Upgrade to latest version of Cleo (#722)

* Upgrade Cleo to the new improved version * Update sonnet script to use sub commands

Upgrade to latest version of Cleo (#722)
* Upgrade Cleo to the new improved version * Update sonnet script to use sub commands
2ff796ed · Sébastien Eustace · GitHub · a51d6642 · 2ff796ed · 2ff796ed
Commit 2ff796ed authored Dec 09, 2018 by Sébastien Eustace Committed by GitHub Dec 09, 2018
70 changed files
--- a/poetry.lock
+++ b/poetry.lock
@@ -34,6 +34,11 @@ optional = false
 python-versions = "*"
 version = "18.2.0"
+[package.extras]
+dev = ["pre-commit", "zope.interface", "sphinx", "zope.interface", "six", "pytest", "pympler", "hypothesis", "coverage"]
+docs = ["zope.interface", "sphinx"]
+tests = ["zope.interface", "six", "pytest", "pympler", "hypothesis", "coverage"]
 [[package]]
 category = "dev"
 description = "The uncompromising code formatter."
@@ -49,6 +54,9 @@ attrs = ">=17.4.0"
 click = ">=6.5"
 toml = ">=0.9.4"
+[package.extras]
+d = ["aiohttp (>=3.3.2)"]
 [[package]]
 category = "main"
 description = "httplib2 caching for requests"
@@ -58,10 +66,17 @@ python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 version = "0.12.5"
 [package.dependencies]
-lockfile = ">=0.9"
 msgpack = "*"
 requests = "*"
+[package.dependencies.lockfile]
+optional = true
+version = ">=0.9"
+[package.extras]
+filecache = ["lockfile (>=0.9)"]
+redis = ["redis (>=2.10.5)"]
 [[package]]
 category = "dev"
 description = "A decorator for caching properties in classes."
@@ -78,6 +93,11 @@ optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 version = "0.2.0"
+[package.extras]
+memcached = ["python-memcached (>=1.59.0.0,<2.0.0.0)"]
+msgpack = ["msgpack-python (>=0.5.0.0,<0.6.0.0)"]
+redis = ["redis (>=2.10.0.0,<3.0.0.0)"]
 [[package]]
 category = "main"
 description = "Python package for providing Mozilla's CA Bundle."
@@ -111,9 +131,10 @@ description = "Cleo allows you to create beautiful and testable command-line int
 name = "cleo"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
-version = "0.6.8"
+version = "0.7.2"
 [package.dependencies]
+clikit = ">=0.2.0,<0.3.0"
 pastel = ">=0.1.0,<0.2.0"
 pylev = ">=1.3,<2.0"
@@ -127,6 +148,26 @@ python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 version = "7.0"
 [[package]]
+category = "main"
+description = "CliKit is a group of utilities to build beautiful and testable command line interfaces."
+name = "clikit"
+optional = false
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
+version = "0.2.2"
+[package.dependencies]
+pastel = ">=0.1.0,<0.2.0"
+pylev = ">=1.3,<2.0"
+[package.dependencies.enum34]
+python = ">=2.7,<2.8"
+version = ">=1.1,<2.0"
+[package.dependencies.typing]
+python = ">=2.7,<2.8 || >=3.4,<3.5"
+version = ">=3.6,<4.0"
+[[package]]
 category = "dev"
 description = "Cross-platform colored terminal text."
 marker = "sys_platform == \"win32\""
@@ -199,6 +240,13 @@ version = "1.0.1"
 six = ">=1.9"
 webencodings = "*"
+[package.extras]
+all = ["genshi", "chardet (>=2.2)", "datrie", "lxml"]
+chardet = ["chardet (>=2.2)"]
+datrie = ["datrie"]
+genshi = ["genshi"]
+lxml = ["lxml"]
 [[package]]
 category = "dev"
 description = "File identification library for Python"
@@ -262,6 +310,9 @@ version = "2.10"
 [package.dependencies]
 MarkupSafe = ">=0.23"
+[package.extras]
+i18n = ["Babel (>=0.8)"]
 [[package]]
 category = "main"
 description = "An implementation of JSON Schema validation for Python"
@@ -279,6 +330,9 @@ six = ">=1.11.0"
 python = "<3"
 version = "*"
+[package.extras]
+format = ["jsonpointer (>1.13)", "rfc3987", "strict-rfc3339", "webcolors"]
 [[package]]
 category = "dev"
 description = "Python LiveReload is an awesome tool for web developers"
@@ -352,6 +406,10 @@ six = ">=1.9"
 python = "<3.3"
 version = ">=1"
+[package.extras]
+docs = ["sphinx", "Pygments (<2)", "jinja2 (<2.7)", "sphinx (<1.3)"]
+test = ["unittest2 (>=1.1.0)"]
 [[package]]
 category = "dev"
 description = "More routines for operating on iterables, beyond itertools"
@@ -432,6 +490,9 @@ optional = false
 python-versions = "*"
 version = "1.4.2"
+[package.extras]
+testing = ["nose", "coverage"]
 [[package]]
 category = "dev"
 description = "plugin and hook calling mechanisms for python"
@@ -440,6 +501,9 @@ optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
 version = "0.8.0"
+[package.extras]
+dev = ["tox", "pre-commit"]
 [[package]]
 category = "dev"
 description = "A framework for managing and maintaining multi-language pre-commit hooks."
@@ -617,6 +681,10 @@ chardet = ">=3.0.2,<3.1.0"
 idna = ">=2.5,<2.8"
 urllib3 = ">=1.21.1,<1.25"
+[package.extras]
+security = ["idna (>=2.0.0)", "cryptography (>=1.3.4)", "pyOpenSSL (>=0.14)"]
+socks = ["win-inet-pton", "PySocks (>=1.5.6,<1.5.7 || >1.5.7)"]
 [[package]]
 category = "main"
 description = "A utility belt for advanced users of python-requests"
@@ -716,6 +784,10 @@ six = ">=1.0.0,<2"
 toml = ">=0.9.4"
 virtualenv = ">=1.11.2"
+[package.extras]
+docs = ["sphinxcontrib-autoprogram (>=0.1.5)", "pygments-github-lexers (>=0.0.5)", "towncrier (>=18.5.0)", "sphinx (>=1.8.0,<2)"]
+testing = ["pytest-randomly (>=1.2.3,<2)", "pytest-xdist (>=1.22.2,<2)", "pytest-timeout (>=1.3.0,<2)", "pytest-mock (>=1.10.0,<2)", "pytest-cov (>=2.5.1,<3)", "pytest (>=3.0.0,<4)"]
 [[package]]
 category = "main"
 description = "Type Hints for Python"
@@ -733,6 +805,10 @@ optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, <4"
 version = "1.24.1"
+[package.extras]
+secure = ["ipaddress", "certifi", "idna (>=2.0.0)", "cryptography (>=1.3.4)", "pyOpenSSL (>=0.14)"]
+socks = ["PySocks (>=1.5.6,<1.5.7 || >1.5.7,<2.0)"]
 [[package]]
 category = "main"
 description = "Virtual Python Environment builder"
@@ -741,6 +817,10 @@ optional = false
 python-versions = ">=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*"
 version = "16.1.0"
+[package.extras]
+docs = ["sphinx (>=1.8.0,<2)"]
+testing = ["mock", "pytest-timeout (>=1.3.0,<2)", "coverage (>=4.5.0,<5)", "pytest (>=3.0.0,<4)"]
 [[package]]
 category = "main"
 description = "Character encoding aliases for legacy web content"
@@ -750,7 +830,7 @@ python-versions = "*"
 version = "0.5.1"
 [metadata]
-content-hash = "cc0af5d7cff3183d13e844efc25bfabc912de0a22eea948614a0895ab4be5ed1"
+content-hash = "8618ec2332b366abaf70c871e9afd0f52d410e0cf17c9715525b9157c8874161"
 python-versions = "~2.7 || ^3.4"
 [metadata.hashes]
@@ -765,8 +845,9 @@ cachy = ["b71513e5a38ce90c1280c02b7d8d6bb3fdf64666c9cc0584f2479afea097d56c", "b7
 certifi = ["339dc09518b07e2fa7eda5450740925974815557727d6bd35d319c1524a04a4c", "6d58c986d22b038c8c0df30d639f23a3e6d172a05c3583e766f4c0b785c0986a"]
 cfgv = ["73f48a752bd7aab103c4b882d6596c6360b7aa63b34073dd2c35c7b4b8f93010", "d1791caa9ff5c0c7bce80e7ecc1921752a2eb7c2463a08ed9b6c96b85a2f75aa"]
 chardet = ["84ab92ed1c4d4f16916e05906b6b75a6c0fb5db821cc65e70cbd64a3e2a5eaae", "fc323ffcaeaed0e0a02bf4d117757b98aed530d9ed4531e3e15460124c106691"]
-cleo = ["85a63076b72ca376fb06668be1fc7758dc16740b394783d5cc65200c4b32f71b", "9b7f79f1aa470a025c0d28c76aa225ee9e65028d32f80032e871aa3500df61b8"]
+cleo = ["7a5000de616de42fd78f968192651b9174bf333a9079fc9d68ccc672ddfd3624", "a39fa806fd3f64ff0ae4e3a55bb80c8ce60ca73634e13619731d63a04a63be69"]
 click = ["2335065e6395b9e67ca716de5f7526736bfa6ceead690adf616d925bdc622b13", "5b94b49521f6456670fdb30cd82a4eca9412788a93fa6dd6df72c94d5a8ff2d7"]
+clikit = ["9dbdb3a0f3ddcd2e1851f11b13dc5173d8a4333d627be24e46ddbbc0d83a84e8", "b65cecedfabc2c73865454a57faeca8696408130fc5c2c74df0770335c787bec"]
 colorama = ["a3d89af5db9e9806a779a50296b5fdb466e281147c2c235e8225ecc6dbf7bbf3", "c9b54bebe91a6a803e0772c8561d53f2926bfeb17cd141fbabcb08424086595c"]
 contextlib2 = ["509f9419ee91cdd00ba34443217d5ca51f5a364a404e1dce9e8979cea969ca48", "f5260a6e679d2ff42ec91ec5252f4eeffdcf21053db9113bd0a8e4d953769c00"]
 coverage = ["06123b58a1410873e22134ca2d88bd36680479fe354955b3579fb8ff150e4d27", "09e47c529ff77bf042ecfe858fb55c3e3eb97aac2c87f0349ab5a7efd6b3939f", "0a1f9b0eb3aa15c990c328535655847b3420231af299386cfe5efc98f9c250fe", "0cc941b37b8c2ececfed341444a456912e740ecf515d560de58b9a76562d966d", "0d34245f824cc3140150ab7848d08b7e2ba67ada959d77619c986f2062e1f0e8", "10e8af18d1315de936d67775d3a814cc81d0747a1a0312d84e27ae5610e313b0", "1b4276550b86caa60606bd3572b52769860a81a70754a54acc8ba789ce74d607", "1e8a2627c48266c7b813975335cfdea58c706fe36f607c97d9392e61502dc79d", "258b21c5cafb0c3768861a6df3ab0cfb4d8b495eee5ec660e16f928bf7385390", "2b224052bfd801beb7478b03e8a66f3f25ea56ea488922e98903914ac9ac930b", "3ad59c84c502cd134b0088ca9038d100e8fb5081bbd5ccca4863f3804d81f61d", "447c450a093766744ab53bf1e7063ec82866f27bcb4f4c907da25ad293bba7e3", "46101fc20c6f6568561cdd15a54018bb42980954b79aa46da8ae6f008066a30e", "4710dc676bb4b779c4361b54eb308bc84d64a2fa3d78e5f7228921eccce5d815", "510986f9a280cd05189b42eee2b69fecdf5bf9651d4cd315ea21d24a964a3c36", "5535dda5739257effef56e49a1c51c71f1d37a6e5607bb25a5eee507c59580d1", "5a7524042014642b39b1fcae85fb37556c200e64ec90824ae9ecf7b667ccfc14", "5f55028169ef85e1fa8e4b8b1b91c0b3b0fa3297c4fb22990d46ff01d22c2d6c", "6694d5573e7790a0e8d3d177d7a416ca5f5c150742ee703f3c18df76260de794", "6831e1ac20ac52634da606b658b0b2712d26984999c9d93f0c6e59fe62ca741b", "71afc1f5cd72ab97330126b566bbf4e8661aab7449f08895d21a5d08c6b051ff", "7349c27128334f787ae63ab49d90bf6d47c7288c63a0a5dfaa319d4b4541dd2c", "77f0d9fa5e10d03aa4528436e33423bfa3718b86c646615f04616294c935f840", "828ad813c7cdc2e71dcf141912c685bfe4b548c0e6d9540db6418b807c345ddd", "859714036274a75e6e57c7bab0c47a4602d2a8cfaaa33bbdb68c8359b2ed4f5c", "85a06c61598b14b015d4df233d249cd5abfa61084ef5b9f64a48e997fd829a82", "869ef4a19f6e4c6987e18b315721b8b971f7048e6eaea29c066854242b4e98d9", "8cb4febad0f0b26c6f62e1628f2053954ad2c555d67660f28dfb1b0496711952", "977e2d9a646773cc7428cdd9a34b069d6ee254fadfb4d09b3f430e95472f3cf3", "99bd767c49c775b79fdcd2eabff405f1063d9d959039c0bdd720527a7738748a", "a5c58664b23b248b16b96253880b2868fb34358911400a7ba39d7f6399935389", "aaa0f296e503cda4bc07566f592cd7a28779d433f3a23c48082af425d6d5a78f", "ab235d9fe64833f12d1334d29b558aacedfbca2356dfb9691f2d0d38a8a7bfb4", "b3b0c8f660fae65eac74fbf003f3103769b90012ae7a460863010539bb7a80da", "bab8e6d510d2ea0f1d14f12642e3f35cefa47a9b2e4c7cea1852b52bc9c49647", "c45297bbdbc8bb79b02cf41417d63352b70bcb76f1bbb1ee7d47b3e89e42f95d", "d19bca47c8a01b92640c614a9147b081a1974f69168ecd494687c827109e8f42", "d64b4340a0c488a9e79b66ec9f9d77d02b99b772c8b8afd46c1294c1d39ca478", "da969da069a82bbb5300b59161d8d7c8d423bc4ccd3b410a9b4d8932aeefc14b", "ed02c7539705696ecb7dc9d476d861f3904a8d2b7e894bd418994920935d36bb", "ee5b8abc35b549012e03a7b1e86c09491457dba6c94112a2482b18589cc2bdb9"]

--- a/poetry/console/application.py
+++ b/poetry/console/application.py
 import os
-import re
-import sys
-import traceback
 from cleo import Application as BaseApplication
-from cleo.formatters import Formatter
-from cleo.inputs import ArgvInput
-from cleo.outputs import ConsoleOutput
-from cleo.outputs import Output
 from poetry import __version__
-from poetry.io.raw_argv_input import RawArgvInput
 from .commands import AboutCommand
 from .commands import AddCommand
 from .commands import BuildCommand
@@ -34,22 +25,25 @@ from .commands import ShowCommand
 from .commands import UpdateCommand
 from .commands import VersionCommand
-from .commands.cache import CacheClearCommand
+from .commands.debug import DebugCommand
+from .commands.cache import CacheCommand
-from .commands.debug import DebugInfoCommand
+from .commands.self import SelfCommand
-from .commands.debug import DebugResolveCommand
-from .commands.self import SelfUpdateCommand
+from .config import ApplicationConfig
 class Application(BaseApplication):
    def __init__(self):
-        super(Application, self).__init__("Poetry", __version__)
+        super(Application, self).__init__(
+            "poetry", __version__, config=ApplicationConfig("poetry", __version__)
+        )
        self._poetry = None
-        self._skip_io_configuration = False
-        self._formatter = Formatter(True)
+        for command in self.get_default_commands():
-        self._formatter.add_style("error", "red", options=["bold"])
+            self.add(command)
    @property
    def poetry(self):
@@ -65,47 +59,8 @@ class Application(BaseApplication):
    def reset_poetry(self):  # type: () -> None
        self._poetry = None
-    def run(self, i=None, o=None):  # type: (...) -> int
-        if i is None:
-            i = ArgvInput()
-        if o is None:
-            o = ConsoleOutput()
-            self._formatter.with_colors(o.is_decorated())
-            o.set_formatter(self._formatter)
-        name = i.get_first_argument()
-        if name in ["run", "script"]:
-            self._skip_io_configuration = True
-            i = RawArgvInput()
-        return super(Application, self).run(i, o)
-    def do_run(self, i, o):
-        name = self.get_command_name(i)
-        if name not in ["run", "script"]:
-            return super(Application, self).do_run(i, o)
-        command = self.find(name)
-        self._running_command = command
-        status_code = command.run(i, o)
-        self._running_command = None
-        return status_code
-    def configure_io(self, i, o):
-        if self._skip_io_configuration:
-            return
-        super(Application, self).configure_io(i, o)
    def get_default_commands(self):  # type: () -> list
-        commands = super(Application, self).get_default_commands()
+        commands = [
-        commands += [
            AboutCommand(),
            AddCommand(),
            BuildCommand(),
@@ -129,74 +84,16 @@ class Application(BaseApplication):
        ]
        # Cache commands
-        commands += [CacheClearCommand()]
+        commands += [CacheCommand()]
-        # Debug commands
+        # Debug command
-        commands += [DebugInfoCommand(), DebugResolveCommand()]
+        commands += [DebugCommand()]
        # Self commands
-        commands += [SelfUpdateCommand()]
+        commands += [SelfCommand()]
        return commands
-    def render_exception(self, e, o):
-        tb = traceback.extract_tb(sys.exc_info()[2])
-        title = "[<error>%s</error>]  " % e.__class__.__name__
-        l = len(title)
-        width = self._terminal.width
-        if not width:
-            width = sys.maxsize
-        formatter = o.get_formatter()
-        lines = []
-        for line in re.split(r"\r?\n", str(e)):
-            for splitline in [
-                line[x : x + (width - 4)] for x in range(0, len(line), width - 4)
-            ]:
-                line_length = (
-                    len(re.sub(r"\[[^m]*m", "", formatter.format(splitline))) + 4
-                )
-                lines.append((splitline, line_length))
-                l = max(line_length, l)
-        messages = []
-        empty_line = formatter.format("%s" % (" " * l))
-        messages.append(empty_line)
-        messages.append(
-            formatter.format("%s%s" % (title, " " * max(0, l - len(title))))
-        )
-        for line in lines:
-            messages.append(
-                formatter.format(
-                    "<error>%s  %s</error>" % (line[0], " " * (l - line[1]))
-                )
-            )
-        messages.append(empty_line)
-        o.writeln(messages, Output.OUTPUT_RAW)
-        if Output.VERBOSITY_VERBOSE <= o.get_verbosity():
-            o.writeln("<comment>Exception trace:</comment>")
-            for exc_info in tb:
-                file_ = exc_info[0]
-                line_number = exc_info[1]
-                function = exc_info[2]
-                line = exc_info[3]
-                o.writeln(
-                    " <info>%s</info> in <fg=cyan>%s()</> "
-                    "at line <info>%s</info>" % (file_, function, line_number)
-                )
-                o.writeln("   %s" % line)
-            o.writeln("")
-        if self._running_command is not None:
-            o.writeln("<info>%s</info>" % self._running_command.get_synopsis())
-            o.writeln("")
+if __name__ == "__main__":
+    Application().run()
--- a/poetry/console/styles/__init__.py
+++ b/poetry/console/styles/__init__.py
--- a/poetry/console/args/run_args_parser.py
+++ b/poetry/console/args/run_args_parser.py
+from clikit.api.args import Args
+from clikit.api.args import RawArgs
+from clikit.api.args.format import ArgsFormat
+from clikit.api.args.format import ArgsFormatBuilder
+from clikit.args import DefaultArgsParser
+class RunArgsParser(DefaultArgsParser):
+    """
+    Parser that just parses command names and leave the rest
+    alone to be passed to the command.
+    """
+    def parse(
+        self, args, fmt, lenient=False
+    ):  # type: (RawArgs, ArgsFormat, bool) -> Args
+        builder = ArgsFormatBuilder()
+        builder.set_command_names(*fmt.get_command_names())
+        builder.set_arguments(*fmt.get_arguments().values())
+        fmt = builder.format
+        return super(RunArgsParser, self).parse(args, fmt, True)
+    def _parse(
+        self, raw_args, fmt, lenient
+    ):  # type: (RawArgs, ArgsFormat, bool) -> None
+        """
+        Parse everything as a single, multi-valued argument.
+        """
+        tokens = raw_args.tokens[:]
+        last_arg = list(fmt.get_arguments().values())[-1]
+        self._arguments[last_arg.name] = []
+        while True:
+            try:
+                token = tokens.pop(0)
+            except IndexError:
+                break
+            self._arguments[last_arg.name].append(token)
--- a/poetry/console/commands/add.py
+++ b/poetry/console/commands/add.py
@@ -25,7 +25,7 @@ class AddCommand(EnvCommand, InitCommand):
 If you do not specify a version constraint, poetry will choose a suitable one based on the available package versions.
 """
-    _loggers = ["poetry.repositories.pypi_repository"]
+    loggers = ["poetry.repositories.pypi_repository"]
    def handle(self):
        from poetry.installation import Installer
@@ -124,11 +124,7 @@ If you do not specify a version constraint, poetry will choose a suitable one ba
        self.reset_poetry()
        installer = Installer(
-            self.output,
+            self.io, self.env, self.poetry.package, self.poetry.locker, self.poetry.pool
-            self.env,
-            self.poetry.package,
-            self.poetry.locker,
-            self.poetry.pool,
        )
        installer.dry_run(self.option("dry-run"))

--- a/poetry/console/commands/build.py
+++ b/poetry/console/commands/build.py
@@ -23,5 +23,5 @@ class BuildCommand(EnvCommand):
            )
        )
-        builder = Builder(self.poetry, self.env, self.output)
+        builder = Builder(self.poetry, self.env, self.io)
        builder.build(fmt)
--- a/poetry/console/commands/cache/__init__.py
+++ b/poetry/console/commands/cache/__init__.py
-from .clear import CacheClearCommand
+from .cache import CacheCommand
--- a/poetry/console/commands/cache/cache.py
+++ b/poetry/console/commands/cache/cache.py
+from ..command import Command
+from .clear import CacheClearCommand
+class CacheCommand(Command):
+    """
+    Interact with Poetry's cache.
+    cache
+    """
+    commands = [CacheClearCommand()]
+    def handle(self):
+        return self.call("help", self._config.name)
--- a/poetry/console/commands/cache/clear.py
+++ b/poetry/console/commands/cache/clear.py
@@ -7,7 +7,7 @@ class CacheClearCommand(Command):
    """
    Clears poetry's cache.
-    cache:clear
+    clear
        { cache : The name of the cache to clear. }
        { --all : Clear all caches. }
    """

--- a/poetry/console/commands/check.py
+++ b/poetry/console/commands/check.py
@@ -17,7 +17,7 @@ class CheckCommand(Command):
            return 0
        for error in check_result["errors"]:
-            self.error("Error: {}".format(error))
+            self.line("<error>Error: {}</error>".format(error))
        for error in check_result["warnings"]:
            self.line("<warning>Warning: {}</warning>".format(error))

--- a/poetry/console/commands/command.py
+++ b/poetry/console/commands/command.py
-import logging
 from cleo import Command as BaseCommand
-from ..styles.poetry import PoetryStyle
-class CommandFormatter(logging.Formatter):
-    _colors = {
-        "error": "fg=red",
-        "warning": "fg=yellow",
-        "debug": "debug",
-        "info": "fg=blue",
-    }
-    def format(self, record):
-        if not record.exc_info:
-            level = record.levelname.lower()
-            msg = record.msg
-            if level in self._colors:
-                msg = "<{}>{}</>".format(self._colors[level], msg)
-            return msg
-        return super(CommandFormatter, self).format(record)
-class CommandHandler(logging.Handler):
-    def __init__(self, command):
-        self._command = command
-        output = self._command.output
-        level = logging.WARNING
-        if output.is_debug():
-            level = logging.DEBUG
-        elif output.is_very_verbose() or output.is_verbose():
-            level = logging.INFO
-        super(CommandHandler, self).__init__(level)
-    def emit(self, record):
-        try:
-            msg = self.format(record)
-            level = record.levelname.lower()
-            err = level in ("warning", "error", "exception", "critical")
-            if err:
-                self._command.output.write_error(msg, newline=True)
-            else:
-                self._command.line(msg)
-        except Exception:
-            self.handleError(record)
 class Command(BaseCommand):
-    _loggers = []
+    loggers = []
    @property
    def poetry(self):
-        return self.get_application().poetry
+        return self.application.poetry
    def reset_poetry(self):  # type: () -> None
-        self.get_application().reset_poetry()
+        self.application.reset_poetry()
-    def run(self, i, o):  # type: () -> int
-        """
-        Initialize command.
-        """
-        self.input = i
-        self.output = PoetryStyle(i, o)
-        for logger in self._loggers:
-            self.register_logger(logging.getLogger(logger))
-        return super(BaseCommand, self).run(i, o)
-    def register_logger(self, logger):
-        """
-        Register a new logger.
-        """
-        handler = CommandHandler(self)
-        handler.setFormatter(CommandFormatter())
-        logger.handlers = [handler]
-        logger.propagate = False
-        output = self.output
-        level = logging.WARNING
-        if output.is_debug():
-            level = logging.DEBUG
-        elif output.is_very_verbose() or output.is_verbose():
-            level = logging.INFO
-        logger.setLevel(level)
--- a/poetry/console/commands/config.py
+++ b/poetry/console/commands/config.py
@@ -18,7 +18,7 @@ class ConfigCommand(Command):
    Sets/Gets config options.
    config
-        { key : Setting key. }
+        { key? : Setting key. }
        { value?* : Setting value. }
        { --list : List configuration settings }
        { --unset : Unset configuration setting }
@@ -40,7 +40,7 @@ To remove a repository (repo is a short alias for repositories):
        super(ConfigCommand, self).__init__()
-        self._config = Config.create("config.toml")
+        self._settings_config = Config.create("config.toml")
        self._auth_config = Config.create("auth.toml")
    @property
@@ -74,12 +74,10 @@ To remove a repository (repo is a short alias for repositories):
    def initialize(self, i, o):
        from poetry.utils._compat import decode
-        super(ConfigCommand, self).initialize(i, o)
        # Create config file if it does not exist
-        if not self._config.file.exists():
+        if not self._settings_config.file.exists():
-            self._config.file.parent.mkdir(parents=True, exist_ok=True)
+            self._settings_config.file.parent.mkdir(parents=True, exist_ok=True)
-            with self._config.file.open("w", encoding="utf-8") as f:
+            with self._settings_config.file.open("w", encoding="utf-8") as f:
                f.write(decode(TEMPLATE))
        if not self._auth_config.file.exists():
@@ -89,7 +87,7 @@ To remove a repository (repo is a short alias for repositories):
    def handle(self):
        if self.option("list"):
-            self._list_configuration(self._config.content)
+            self._list_configuration(self._settings_config.content)
            return 0
@@ -106,10 +104,12 @@ To remove a repository (repo is a short alias for repositories):
            if m:
                if not m.group(1):
                    value = {}
-                    if self._config.setting("repositories") is not None:
+                    if self._settings_config.setting("repositories") is not None:
-                        value = self._config.setting("repositories")
+                        value = self._settings_config.setting("repositories")
                else:
-                    repo = self._config.setting("repositories.{}".format(m.group(1)))
+                    repo = self._settings_config.setting(
+                        "repositories.{}".format(m.group(1))
+                    )
                    if repo is None:
                        raise ValueError(
                            "There is no {} repository defined".format(m.group(1))
@@ -124,7 +124,9 @@ To remove a repository (repo is a short alias for repositories):
                    raise ValueError("There is no {} setting.".format(setting_key))
                values = self._get_setting(
-                    self._config.content, setting_key, default=values[setting_key][-1]
+                    self._settings_config.content,
+                    setting_key,
+                    default=values[setting_key][-1],
                )
                for value in values:
@@ -150,20 +152,26 @@ To remove a repository (repo is a short alias for repositories):
                raise ValueError("You cannot remove the [repositories] section")
            if self.option("unset"):
-                repo = self._config.setting("repositories.{}".format(m.group(1)))
+                repo = self._settings_config.setting(
+                    "repositories.{}".format(m.group(1))
+                )
                if repo is None:
                    raise ValueError(
                        "There is no {} repository defined".format(m.group(1))
                    )
-                self._config.remove_property("repositories.{}".format(m.group(1)))
+                self._settings_config.remove_property(
+                    "repositories.{}".format(m.group(1))
+                )
                return 0
            if len(values) == 1:
                url = values[0]
-                self._config.add_property("repositories.{}.url".format(m.group(1)), url)
+                self._settings_config.add_property(
+                    "repositories.{}.url".format(m.group(1)), url
+                )
                return 0
@@ -222,12 +230,12 @@ To remove a repository (repo is a short alias for repositories):
        if not validator(value):
            raise RuntimeError('"{}" is an invalid value for {}'.format(value, key))
-        self._config.add_property(key, normalizer(value))
+        self._settings_config.add_property(key, normalizer(value))
        return 0
    def _remove_single_value(self, key):
-        self._config.remove_property(key)
+        self._settings_config.remove_property(key)
        return 0

--- a/poetry/console/commands/debug/__init__.py
+++ b/poetry/console/commands/debug/__init__.py
-from .info import DebugInfoCommand
+from .debug import DebugCommand
-from .resolve import DebugResolveCommand
--- a/poetry/console/commands/debug/debug.py
+++ b/poetry/console/commands/debug/debug.py
+from ..command import Command
+from .info import DebugInfoCommand
+from .resolve import DebugResolveCommand
+class DebugCommand(Command):
+    """
+    Debug various elements of Poetry.
+    debug
+    """
+    commands = [DebugInfoCommand().default(), DebugResolveCommand()]
--- a/poetry/console/commands/debug/info.py
+++ b/poetry/console/commands/debug/info.py
@@ -8,7 +8,7 @@ class DebugInfoCommand(Command):
    """
    Shows debug information.
-    debug:info
+    info
    """
    def handle(self):
@@ -19,18 +19,17 @@ class DebugInfoCommand(Command):
        poetry_python_version = ".".join(str(s) for s in sys.version_info[:3])
-        self.output.title("Poetry")
+        self.line("")
-        self.output.listing(
+        self.line("<b>Poetry</b>")
-            [
+        self.line("")
-                "<info>Version</info>: <comment>{}</>".format(poetry.VERSION),
+        self.line("<info>Version</info>: <comment>{}</>".format(poetry.VERSION))
-                "<info>Python</info>:  <comment>{}</>".format(poetry_python_version),
+        self.line("<info>Python</info>:  <comment>{}</>".format(poetry_python_version))
-            ]
-        )
        self.line("")
        env_python_version = ".".join(str(s) for s in env.version_info[:3])
-        self.output.title("Virtualenv")
+        self.line("<b>Virtualenv</b>")
+        self.line("")
        listing = [
            "<info>Python</info>:         <comment>{}</>".format(env_python_version),
            "<info>Implementation</info>: <comment>{}</>".format(
@@ -46,17 +45,21 @@ class DebugInfoCommand(Command):
                    tag="comment" if env.is_sane() else "error", is_valid=env.is_sane()
                )
            )
-        self.output.listing(listing)
+        for line in listing:
+            self.line(line)
        self.line("")
-        self.output.title("System")
+        self.line("<b>System</b>")
-        self.output.listing(
+        self.line("")
-            [
+        listing = [
            "<info>Platform</info>: <comment>{}</>".format(sys.platform),
            "<info>OS</info>:       <comment>{}</>".format(os.name),
            "<info>Python</info>:   <comment>{}</>".format(env.base),
        ]
-        )
+        for line in listing:
+            self.line(line)
        self.line("")
--- a/poetry/console/commands/debug/resolve.py
+++ b/poetry/console/commands/debug/resolve.py
@@ -9,7 +9,7 @@ class DebugResolveCommand(Command):
    """
    Debugs dependency resolution.
-    debug:resolve
+    resolve
        { package?* : packages to resolve. }
        { --E|extras=* : Extras to activate for the dependency. }
        { --python= : Python version(s) to use for resolution. }
@@ -17,7 +17,7 @@ class DebugResolveCommand(Command):
        { --install : Show what would be installed for the current system. }
    """
-    _loggers = ["poetry.repositories.pypi_repository"]
+    loggers = ["poetry.repositories.pypi_repository"]
    def handle(self):
        from poetry.packages import ProjectPackage
@@ -54,7 +54,7 @@ class DebugResolveCommand(Command):
        pool = self.poetry.pool
-        solver = Solver(package, pool, Repository(), Repository(), self.output)
+        solver = Solver(package, pool, Repository(), Repository(), self._io)
        ops = solver.solve()
@@ -63,9 +63,8 @@ class DebugResolveCommand(Command):
        self.line("")
        if self.option("tree"):
-            show_command = self.get_application().find("show")
+            show_command = self.application.find("show")
-            show_command.output = self.output
+            show_command.init_styles(self.io)
-            show_command.init_styles()
            packages = [op.package for op in ops]
            repo = Repository(packages)
@@ -74,7 +73,7 @@ class DebugResolveCommand(Command):
            for pkg in repo.packages:
                for require in requires:
                    if pkg.name == require.name:
-                        show_command.display_package_tree(pkg, repo)
+                        show_command.display_package_tree(self.io, pkg, repo)
                        break
            return 0

--- a/poetry/console/commands/env_command.py
+++ b/poetry/console/commands/env_command.py
@@ -7,35 +7,9 @@ class EnvCommand(Command):
        super(EnvCommand, self).__init__()
-    def initialize(self, i, o):
-        from poetry.semver import parse_constraint
-        from poetry.utils.env import Env
-        super(EnvCommand, self).initialize(i, o)
-        # Checking compatibility of the current environment with
-        # the python dependency specified in pyproject.toml
-        current_env = Env.get(self.poetry.file.parent)
-        supported_python = self.poetry.package.python_constraint
-        current_python = parse_constraint(
-            ".".join(str(v) for v in current_env.version_info[:3])
-        )
-        if not supported_python.allows(current_python):
-            raise RuntimeError(
-                "The current Python version ({}) is not supported by the project ({})\n"
-                "Please activate a compatible Python version.".format(
-                    current_python, self.poetry.package.python_versions
-                )
-            )
-        self._env = Env.create_venv(
-            self.poetry.file.parent, o, self.poetry.package.name
-        )
-        if self._env.is_venv() and o.is_verbose():
-            o.writeln("Using virtualenv: <comment>{}</>".format(self._env.path))
    @property
    def env(self):
        return self._env
+    def set_env(self, env):
+        self._env = env
--- a/poetry/console/commands/export.py
+++ b/poetry/console/commands/export.py
@@ -23,11 +23,11 @@ class ExportCommand(Command):
        if not locker.is_locked():
            self.line("<comment>The lock file does not exist. Locking.</comment>")
            options = []
-            if self.output.is_debug():
+            if self.io.is_debug():
                options.append(("-vvv", None))
-            elif self.output.is_very_verbose():
+            elif self.io.is_very_verbose():
                options.append(("-vv", None))
-            elif self.output.is_verbose():
+            elif self.io.is_verbose():
                options.append(("-v", None))
            self.call("lock", options)

--- a/poetry/console/commands/init.py
+++ b/poetry/console/commands/init.py
@@ -41,18 +41,16 @@ The <info>init</info> command creates a basic <comment>pyproject.toml</> file in
        from poetry.vcs.git import GitConfig
        if (Path.cwd() / "pyproject.toml").exists():
-            self.error("A pyproject.toml file already exists.")
+            self.line("<error>A pyproject.toml file already exists.</error>")
            return 1
        vcs_config = GitConfig()
+        self.line("")
        self.line(
-            [
+            "This command will guide you through creating your <info>pyproject.toml</> config."
-                "",
-                "This command will guide you through creating your <info>pyproject.toml</> config.",
-                "",
-            ]
        )
+        self.line("")
        name = self.option("name")
        if not name:
@@ -86,7 +84,7 @@ The <info>init</info> command creates a basic <comment>pyproject.toml</> file in
        question = self.create_question(
            "Author [<comment>{}</comment>, n to skip]: ".format(author), default=author
        )
-        question.validator = lambda v: self._validate_author(v, author)
+        question.set_validator(lambda v: self._validate_author(v, author))
        author = self.ask(question)
        if not author:
@@ -99,7 +97,7 @@ The <info>init</info> command creates a basic <comment>pyproject.toml</> file in
        question = self.create_question(
            "License [<comment>{}</comment>]: ".format(license), default=license
        )
-        question.validator = self._validate_license
+        question.set_validator(self._validate_license)
        license = self.ask(question)
        current_env = Env.get(Path.cwd())
@@ -125,6 +123,7 @@ The <info>init</info> command creates a basic <comment>pyproject.toml</> file in
            requirements = self._format_requirements(
                self._determine_requirements(self.option("dependency"))
            )
+            self.line("")
        dev_requirements = {}
@@ -136,6 +135,7 @@ The <info>init</info> command creates a basic <comment>pyproject.toml</> file in
            dev_requirements = self._format_requirements(
                self._determine_requirements(self.option("dev-dependency"))
            )
+            self.line("")
        layout_ = layout("standard")(
            name,
@@ -149,9 +149,11 @@ The <info>init</info> command creates a basic <comment>pyproject.toml</> file in
        )
        content = layout_.generate_poetry_content()
-        if self.input.is_interactive():
+        if self.io.is_interactive():
            self.line("<info>Generated file</info>")
-            self.line(["", content, ""])
+            self.line("")
+            self.line(content)
+            self.line("")
        if not self.confirm("Do you confirm generation?", True):
            self.line("<error>Command aborted</error>")
@@ -203,7 +205,7 @@ The <info>init</info> command creates a basic <comment>pyproject.toml</> file in
                    constraint = self.ask(question)
-                    if constraint is False:
+                    if constraint is None:
                        _, constraint = self._find_best_version_for_package(package)
                        self.line(

--- a/poetry/console/commands/install.py
+++ b/poetry/console/commands/install.py
@@ -26,19 +26,15 @@ exist it will look for <comment>pyproject.toml</> and do the same.
    _loggers = ["poetry.repositories.pypi_repository"]
    def handle(self):
+        from clikit.io import NullIO
        from poetry.installation import Installer
-        from poetry.io import NullIO
        from poetry.masonry.builders import SdistBuilder
        from poetry.masonry.utils.module import ModuleOrPackageNotFound
        from poetry.utils._compat import decode
        from poetry.utils.env import NullEnv
        installer = Installer(
-            self.output,
+            self.io, self.env, self.poetry.package, self.poetry.locker, self.poetry.pool
-            self.env,
-            self.poetry.package,
-            self.poetry.locker,
-            self.poetry.pool,
        )
        extras = []

--- a/poetry/console/commands/lock.py
+++ b/poetry/console/commands/lock.py
@@ -20,11 +20,7 @@ the current directory, processes it, and locks the depdencies in the <comment>po
        from poetry.installation import Installer
        installer = Installer(
-            self.output,
+            self.io, self.env, self.poetry.package, self.poetry.locker, self.poetry.pool
-            self.env,
-            self.poetry.package,
-            self.poetry.locker,
-            self.poetry.pool,
        )
        installer.update(True)

--- a/poetry/console/commands/publish.py
+++ b/poetry/console/commands/publish.py
@@ -24,7 +24,7 @@ the config command.
    def handle(self):
        from poetry.masonry.publishing.publisher import Publisher
-        publisher = Publisher(self.poetry, self.output)
+        publisher = Publisher(self.poetry, self.io)
        # Building package first, if told
        if self.option("build"):

--- a/poetry/console/commands/remove.py
+++ b/poetry/console/commands/remove.py
@@ -17,7 +17,7 @@ list of installed packages
 <info>poetry remove</info>"""
-    _loggers = ["poetry.repositories.pypi_repository"]
+    loggers = ["poetry.repositories.pypi_repository"]
    def handle(self):
        from poetry.installation import Installer
@@ -55,11 +55,7 @@ list of installed packages
        self.reset_poetry()
        installer = Installer(
-            self.output,
+            self.io, self.env, self.poetry.package, self.poetry.locker, self.poetry.pool
-            self.env,
-            self.poetry.package,
-            self.poetry.locker,
-            self.poetry.pool,
        )
        installer.dry_run(self.option("dry-run"))

--- a/poetry/console/commands/run.py
+++ b/poetry/console/commands/run.py
@@ -9,6 +9,13 @@ class RunCommand(EnvCommand):
        { args* : The command and arguments/options to run. }
    """
+    def __init__(self):  # type: () -> None
+        from poetry.console.args.run_args_parser import RunArgsParser
+        super(RunCommand, self).__init__()
+        self.config.set_args_parser(RunArgsParser())
    def handle(self):
        args = self.argument("args")
        script = args[0]
@@ -48,22 +55,5 @@ class RunCommand(EnvCommand):
        package = poetry.package
        path = poetry.file.parent
        module = Module(package.name, path.as_posix(), package.packages)
-        return module
-    def merge_application_definition(self, merge_args=True):
+        return module
-        if self._application is None or (
-            self._application_definition_merged
-            and (self._application_definition_merged_with_args or not merge_args)
-        ):
-            return
-        if merge_args:
-            current_arguments = self._definition.get_arguments()
-            self._definition.set_arguments(
-                self._application.get_definition().get_arguments()
-            )
-            self._definition.add_arguments(current_arguments)
-        self._application_definition_merged = True
-        if merge_args:
-            self._application_definition_merged_with_args = True
--- a/poetry/console/commands/script.py
+++ b/poetry/console/commands/script.py
@@ -52,22 +52,5 @@ class ScriptCommand(EnvCommand):
        package = poetry.package
        path = poetry.file.parent
        module = Module(package.name, path.as_posix())
-        return module
-    def merge_application_definition(self, merge_args=True):
-        if self._application is None or (
-            self._application_definition_merged
-            and (self._application_definition_merged_with_args or not merge_args)
-        ):
-            return
-        if merge_args:
-            current_arguments = self._definition.get_arguments()
-            self._definition.set_arguments(
-                self._application.get_definition().get_arguments()
-            )
-            self._definition.add_arguments(current_arguments)
-        self._application_definition_merged = True
+        return module
-        if merge_args:
-            self._application_definition_merged_with_args = True
--- a/poetry/console/commands/self/__init__.py
+++ b/poetry/console/commands/self/__init__.py
-from .update import SelfUpdateCommand
+from .self import SelfCommand
--- a/poetry/console/commands/self/self.py
+++ b/poetry/console/commands/self/self.py
+from ..command import Command
+from .update import SelfUpdateCommand
+class SelfCommand(Command):
+    """
+    Interact with Poetry directly.
+    """
+    name = "self"
+    commands = [SelfUpdateCommand()]
+    def handle(self):
+        return self.call("help", self._config.name)
--- a/poetry/console/commands/self/update.py
+++ b/poetry/console/commands/self/update.py
@@ -22,7 +22,7 @@ class SelfUpdateCommand(Command):
    """
    Updates poetry to the latest version.
-    self:update
+    update
        { version? : The version to update to. }
        { --preview : Install prereleases. }
    """
@@ -51,7 +51,6 @@ class SelfUpdateCommand(Command):
        from poetry.repositories.pypi_repository import PyPiRepository
        from poetry.semver import Version
        from poetry.utils._compat import Path
-        from poetry.utils._compat import decode
        current = Path(__file__)
        try:
@@ -104,20 +103,7 @@ class SelfUpdateCommand(Command):
            self.line("You are using the latest version")
            return
-        try:
        self.update(release)
-        except subprocess.CalledProcessError as e:
-            self.line("")
-            self.output.block(
-                [
-                    "[CalledProcessError]",
-                    "An error has occured: {}".format(str(e)),
-                    decode(e.output),
-                ],
-                style="error",
-            )
-            return e.returncode
    def update(self, release):
        version = release.version

--- a/poetry/console/commands/show.py
+++ b/poetry/console/commands/show.py
 # -*- coding: utf-8 -*-
-import sys
 from .env_command import EnvCommand
@@ -24,16 +22,17 @@ lists all packages available."""
    colors = ["green", "yellow", "cyan", "magenta", "blue"]
    def handle(self):
+        from clikit.utils.terminal import Terminal
        from poetry.repositories.installed_repository import InstalledRepository
        from poetry.semver import Version
        package = self.argument("package")
        if self.option("tree"):
-            self.init_styles()
+            self.init_styles(self.io)
        if self.option("outdated"):
-            self.input.set_option("latest", True)
+            self._args.set_option("latest", True)
        include_dev = not self.option("no-dev")
        locked_repo = self.poetry.locker.locked_repository(include_dev)
@@ -45,13 +44,13 @@ lists all packages available."""
            for package in packages:
                for require in requires:
                    if package.name == require.name:
-                        self.display_package_tree(package, locked_repo)
+                        self.display_package_tree(self._io, package, locked_repo)
                        break
            return 0
        table = self.table(style="compact")
-        table.get_style().set_vertical_border_char("")
+        # table.style.line_vc_char = ""
        locked_packages = locked_repo.packages
        if package:
@@ -65,7 +64,7 @@ lists all packages available."""
                raise ValueError("Package {} not found".format(package))
            if self.option("tree"):
-                self.display_package_tree(pkg, locked_repo)
+                self.display_package_tree(self.io, pkg, locked_repo)
                return 0
@@ -92,7 +91,7 @@ lists all packages available."""
        show_latest = self.option("latest")
        show_all = self.option("all")
-        terminal = self.get_application().terminal
+        terminal = Terminal()
        width = terminal.width
        name_length = version_length = latest_length = 0
        latest_packages = {}
@@ -114,7 +113,7 @@ lists all packages available."""
                    continue
            current_length = len(locked.pretty_name)
-            if not self.output.is_decorated():
+            if not self._io.output.supports_ansi():
                installed_status = self.get_installed_status(locked, installed_repo)
                if installed_status == "not-installed":
@@ -158,7 +157,7 @@ lists all packages available."""
                if installed_status == "not-installed":
                    color = "red"
-                    if not self.output.is_decorated():
+                    if not self._io.output.supports_ansi():
                        # Non installed in non decorated mode
                        install_marker = " (!)"
@@ -200,13 +199,13 @@ lists all packages available."""
            self.line(line)
-    def display_package_tree(self, package, installed_repo):
+    def display_package_tree(self, io, package, installed_repo):
-        self.write("<info>{}</info>".format(package.pretty_name))
+        io.write("<info>{}</info>".format(package.pretty_name))
        description = ""
        if package.description:
            description = " " + package.description
-        self.line(" {}{}".format(package.pretty_version, description))
+        io.write_line(" {}{}".format(package.pretty_version, description))
        dependencies = package.requires
        dependencies = sorted(dependencies, key=lambda x: x.name)
@@ -226,17 +225,18 @@ lists all packages available."""
                name=dependency.name,
                constraint=dependency.pretty_constraint,
            )
-            self._write_tree_line(info)
+            self._write_tree_line(io, info)
            tree_bar = tree_bar.replace("└", " ")
            packages_in_tree = [package.name, dependency.name]
            self._display_tree(
-                dependency, installed_repo, packages_in_tree, tree_bar, level + 1
+                io, dependency, installed_repo, packages_in_tree, tree_bar, level + 1
            )
    def _display_tree(
        self,
+        io,
        dependency,
        installed_repo,
        packages_in_tree,
@@ -276,7 +276,7 @@ lists all packages available."""
                constraint=dependency.pretty_constraint,
                warn=circular_warn,
            )
-            self._write_tree_line(info)
+            self._write_tree_line(io, info)
            tree_bar = tree_bar.replace("└", " ")
@@ -284,24 +284,28 @@ lists all packages available."""
                current_tree.append(dependency.name)
                self._display_tree(
-                    dependency, installed_repo, current_tree, tree_bar, level + 1
+                    io, dependency, installed_repo, current_tree, tree_bar, level + 1
                )
-    def _write_tree_line(self, line):
+    def _write_tree_line(self, io, line):
-        if not self.output.is_decorated():
+        if not io.output.supports_ansi():
            line = line.replace("└", "`-")
            line = line.replace("├", "|-")
            line = line.replace("──", "-")
            line = line.replace("│", "|")
-        self.line(line)
+        io.write_line(line)
+    def init_styles(self, io):
+        from clikit.api.formatter import Style
-    def init_styles(self):
        for color in self.colors:
-            self.set_style(color, color)
+            style = Style(color).fg(color)
+            io.output.formatter.add_style(style)
+            io.error_output.formatter.add_style(style)
    def find_latest_package(self, package, include_dev):
-        from poetry.io import NullIO
+        from clikit.io import NullIO
        from poetry.puzzle.provider import Provider
        from poetry.version.version_selector import VersionSelector

--- a/poetry/console/commands/update.py
+++ b/poetry/console/commands/update.py
@@ -13,7 +13,7 @@ class UpdateCommand(EnvCommand):
        { --lock : Do not perform install (only update the lockfile). }
    """
-    _loggers = ["poetry.repositories.pypi_repository"]
+    loggers = ["poetry.repositories.pypi_repository"]
    def handle(self):
        from poetry.installation import Installer
@@ -21,11 +21,7 @@ class UpdateCommand(EnvCommand):
        packages = self.argument("packages")
        installer = Installer(
-            self.output,
+            self.io, self.env, self.poetry.package, self.poetry.locker, self.poetry.pool
-            self.env,
-            self.poetry.package,
-            self.poetry.locker,
-            self.poetry.pool,
        )
        if packages:

--- a/poetry/console/commands/version.py
+++ b/poetry/console/commands/version.py
-import re
 from .command import Command
@@ -8,7 +6,7 @@ class VersionCommand(Command):
    Bumps the version of the project.
    version
-        { version=patch }
+        { version=patch : The version number or the rule to update version }
    """
    help = """\

--- a/poetry/console/config/__init__.py
+++ b/poetry/console/config/__init__.py
+from .application_config import ApplicationConfig
--- a/poetry/console/config/application_config.py
+++ b/poetry/console/config/application_config.py
+import logging
+from cleo.config import ApplicationConfig as BaseApplicationConfig
+from clikit.api.event import ConsoleEvents
+from clikit.api.event import PreHandleEvent
+from clikit.api.formatter import Style
+from poetry.console.commands.command import Command
+from poetry.console.commands.env_command import EnvCommand
+from poetry.console.logging import IOFormatter
+from poetry.console.logging import IOHandler
+class ApplicationConfig(BaseApplicationConfig):
+    def configure(self):
+        super(ApplicationConfig, self).configure()
+        self.add_style(Style("c1").fg("green"))
+        self.add_style(Style("comment").fg("cyan"))
+        self.add_style(Style("error").fg("red").bold())
+        self.add_style(Style("warning").fg("yellow"))
+        self.add_style(Style("debug").fg("black").bold())
+        self.add_event_listener(
+            ConsoleEvents.PRE_HANDLE.value, self.register_command_loggers
+        )
+        self.add_event_listener(ConsoleEvents.PRE_HANDLE.value, self.set_env)
+    def register_command_loggers(
+        self, event, event_name, _
+    ):  # type: (PreHandleEvent, str, ...) -> None
+        command = event.command.config.handler
+        if not isinstance(command, Command):
+            return
+        io = event.io
+        if not command.loggers:
+            return
+        handler = IOHandler(io)
+        handler.setFormatter(IOFormatter())
+        for logger in command.loggers:
+            logger = logging.getLogger(logger)
+            logger.handlers = [handler]
+            logger.propagate = False
+            level = logging.WARNING
+            if io.is_debug():
+                level = logging.DEBUG
+            elif io.is_very_verbose() or io.is_verbose():
+                level = logging.INFO
+            logger.setLevel(level)
+    def set_env(self, event, event_name, _):  # type: (PreHandleEvent, str, ...) -> None
+        from poetry.semver import parse_constraint
+        from poetry.utils.env import Env
+        command = event.command.config.handler
+        if not isinstance(command, EnvCommand):
+            return
+        io = event.io
+        poetry = command.poetry
+        # Checking compatibility of the current environment with
+        # the python dependency specified in pyproject.toml
+        current_env = Env.get(poetry.file.parent)
+        supported_python = poetry.package.python_constraint
+        current_python = parse_constraint(
+            ".".join(str(v) for v in current_env.version_info[:3])
+        )
+        if not supported_python.allows(current_python):
+            raise RuntimeError(
+                "The current Python version ({}) is not supported by the project ({})\n"
+                "Please activate a compatible Python version.".format(
+                    current_python, poetry.package.python_versions
+                )
+            )
+        env = Env.create_venv(poetry.file.parent, io, poetry.package.name)
+        if env.is_venv() and io.is_verbose():
+            io.write_line("Using virtualenv: <comment>{}</>".format(env.path))
+        command.set_env(env)
--- a/poetry/console/logging/__init__.py
+++ b/poetry/console/logging/__init__.py
+from .io_formatter import IOFormatter
+from .io_handler import IOHandler
--- a/poetry/console/logging/io_formatter.py
+++ b/poetry/console/logging/io_formatter.py
+import logging
+class IOFormatter(logging.Formatter):
+    _colors = {
+        "error": "fg=red",
+        "warning": "fg=yellow",
+        "debug": "debug",
+        "info": "fg=blue",
+    }
+    def format(self, record):
+        if not record.exc_info:
+            level = record.levelname.lower()
+            msg = record.msg
+            if level in self._colors:
+                msg = "<{}>{}</>".format(self._colors[level], msg)
+            return msg
+        return super(IOFormatter, self).format(record)
--- a/poetry/console/logging/io_handler.py
+++ b/poetry/console/logging/io_handler.py
+import logging
+class IOHandler(logging.Handler):
+    def __init__(self, io):
+        self._io = io
+        level = logging.WARNING
+        if io.is_debug():
+            level = logging.DEBUG
+        elif io.is_very_verbose() or io.is_verbose():
+            level = logging.INFO
+        super(IOHandler, self).__init__(level)
+    def emit(self, record):
+        try:
+            msg = self.format(record)
+            level = record.levelname.lower()
+            err = level in ("warning", "error", "exception", "critical")
+            if err:
+                self._io.error(msg, newline=True)
+            else:
+                self._io.write_line(msg)
+        except Exception:
+            self.handleError(record)
--- a/poetry/console/styles/poetry.py
+++ b/poetry/console/styles/poetry.py
-from cleo.styles import CleoStyle
-from cleo.styles import OutputStyle
-class PoetryStyle(CleoStyle):
-    def __init__(self, i, o):
-        super(PoetryStyle, self).__init__(i, o)
-        self.output.get_formatter().add_style("error", "red")
-        self.output.get_formatter().add_style("warning", "yellow")
-        self.output.get_formatter().add_style("question", "blue")
-        self.output.get_formatter().add_style("comment", "cyan")
-        self.output.get_formatter().add_style("debug", "black", options=["bold"])
-    def writeln(
-        self,
-        messages,
-        type=OutputStyle.OUTPUT_NORMAL,
-        verbosity=OutputStyle.VERBOSITY_NORMAL,
-    ):
-        if self.output.verbosity >= verbosity:
-            super(PoetryStyle, self).writeln(messages, type=type)
-    def write(
-        self,
-        messages,
-        newline=False,
-        type=OutputStyle.OUTPUT_NORMAL,
-        verbosity=OutputStyle.VERBOSITY_NORMAL,
-    ):
-        if self.output.verbosity >= verbosity:
-            super(PoetryStyle, self).write(messages, newline=newline, type=type)
--- a/poetry/installation/installer.py
+++ b/poetry/installation/installer.py
-import sys
 from typing import List
 from typing import Union
-from poetry.io import NullIO
+from clikit.api.io import IO
+from clikit.io import NullIO
 from poetry.packages import Dependency
 from poetry.packages import Locker
 from poetry.packages import Package
-from poetry.packages.constraints import parse_constraint as parse_generic_constraint
 from poetry.puzzle import Solver
 from poetry.puzzle.operations import Install
 from poetry.puzzle.operations import Uninstall
@@ -17,7 +16,6 @@ from poetry.repositories import Pool
 from poetry.repositories import Repository
 from poetry.repositories.installed_repository import InstalledRepository
 from poetry.semver import parse_constraint
-from poetry.semver import Version
 from poetry.utils.helpers import canonicalize_name
 from .base_installer import BaseInstaller
@@ -27,7 +25,7 @@ from .pip_installer import PipInstaller
 class Installer:
    def __init__(
        self,
-        io,
+        io,  # type: IO
        env,
        package,  # type: Package
        locker,  # type: Locker
@@ -146,7 +144,7 @@ class Installer:
                if extra not in self._package.extras:
                    raise ValueError("Extra [{}] is not specified.".format(extra))
-            self._io.writeln("<info>Updating dependencies</>")
+            self._io.write_line("<info>Updating dependencies</>")
            solver = Solver(
                self._package,
                self._pool,
@@ -157,12 +155,12 @@ class Installer:
            ops = solver.solve(use_latest=self._whitelist)
        else:
-            self._io.writeln("<info>Installing dependencies from lock file</>")
+            self._io.write_line("<info>Installing dependencies from lock file</>")
            locked_repository = self._locker.locked_repository(True)
            if not self._locker.is_fresh():
-                self._io.writeln(
+                self._io.write_line(
                    "<warning>"
                    "Warning: The lock file is not up to date with "
                    "the latest changes in pyproject.toml. "
@@ -220,12 +218,12 @@ class Installer:
        # or optional and not requested, are dropped
        self._filter_operations(ops, local_repo)
-        self._io.new_line()
+        self._io.write_line("")
        # Execute operations
        actual_ops = [op for op in ops if not op.skipped]
        if not actual_ops and (self._execute_operations or self._dry_run):
-            self._io.writeln("Nothing to install or update")
+            self._io.write_line("Nothing to install or update")
        if actual_ops and (self._execute_operations or self._dry_run):
            installs = []
@@ -253,8 +251,8 @@ class Installer:
                elif op.job_type == "uninstall":
                    uninstalls.append(op.package.pretty_name)
-            self._io.new_line()
+            self._io.write_line("")
-            self._io.writeln(
+            self._io.write_line(
                "Package operations: "
                "<info>{}</> install{}, "
                "<info>{}</> update{}, "
@@ -279,10 +277,10 @@ class Installer:
            )
            if updated_lock:
-                self._io.writeln("")
+                self._io.write_line("")
-                self._io.writeln("<info>Writing lock file</>")
+                self._io.write_line("<info>Writing lock file</>")
-        self._io.writeln("")
+        self._io.write_line("")
        for op in ops:
            self._execute(op)
@@ -297,7 +295,7 @@ class Installer:
    def _execute_install(self, operation):  # type: (Install) -> None
        if operation.skipped:
            if self.is_verbose() and (self._execute_operations or self.is_dry_run()):
-                self._io.writeln(
+                self._io.write_line(
                    "  - Skipping <info>{}</> (<comment>{}</>) {}".format(
                        operation.package.pretty_name,
                        operation.package.full_pretty_version,
@@ -308,7 +306,7 @@ class Installer:
            return
        if self._execute_operations or self.is_dry_run():
-            self._io.writeln(
+            self._io.write_line(
                "  - Installing <info>{}</> (<comment>{}</>)".format(
                    operation.package.pretty_name, operation.package.full_pretty_version
                )
@@ -325,7 +323,7 @@ class Installer:
        if operation.skipped:
            if self.is_verbose() and (self._execute_operations or self.is_dry_run()):
-                self._io.writeln(
+                self._io.write_line(
                    "  - Skipping <info>{}</> (<comment>{}</>) {}".format(
                        target.pretty_name,
                        target.full_pretty_version,
@@ -336,7 +334,7 @@ class Installer:
            return
        if self._execute_operations or self.is_dry_run():
-            self._io.writeln(
+            self._io.write_line(
                "  - Updating <info>{}</> (<comment>{}</> -> <comment>{}</>)".format(
                    target.pretty_name,
                    source.full_pretty_version,
@@ -352,7 +350,7 @@ class Installer:
    def _execute_uninstall(self, operation):  # type: (Uninstall) -> None
        if operation.skipped:
            if self.is_verbose() and (self._execute_operations or self.is_dry_run()):
-                self._io.writeln(
+                self._io.write_line(
                    "  - Not removing <info>{}</> (<comment>{}</>) {}".format(
                        operation.package.pretty_name,
                        operation.package.full_pretty_version,
@@ -363,7 +361,7 @@ class Installer:
            return
        if self._execute_operations or self.is_dry_run():
-            self._io.writeln(
+            self._io.write_line(
                "  - Removing <info>{}</> (<comment>{}</>)".format(
                    operation.package.pretty_name, operation.package.full_pretty_version
                )

--- a/poetry/installation/pip_installer.py
+++ b/poetry/installation/pip_installer.py
 import os
-import shutil
 import tempfile
 from subprocess import CalledProcessError
+from clikit.io import NullIO
 from poetry.config import Config
 from poetry.utils.helpers import get_http_basic_auth
 from poetry.utils.helpers import safe_rmtree
@@ -41,7 +42,7 @@ class PipInstaller(BaseInstaller):
        if package.source_type == "legacy" and package.source_url:
            parsed = urlparse.urlparse(package.source_url)
            if parsed.scheme == "http":
-                self._io.write_error(
+                self._io.error(
                    "    <warning>Installing from unsecure host: {}</warning>".format(
                        parsed.hostname
                    )
@@ -152,7 +153,6 @@ class PipInstaller(BaseInstaller):
        return name
    def install_directory(self, package):
-        from poetry.io import NullIO
        from poetry.masonry.builder import SdistBuilder
        from poetry.poetry import Poetry
        from poetry.utils._compat import decode

--- a/poetry/io/__init__.py
+++ b/poetry/io/__init__.py
-from .null_io import NullIO
--- a/poetry/io/null_io.py
+++ b/poetry/io/null_io.py
-from cleo.inputs import ListInput
-from cleo.outputs import NullOutput
-from poetry.console.styles.poetry import PoetryStyle
-class NullIO(PoetryStyle):
-    def __init__(self):
-        super(NullIO, self).__init__(ListInput([]), NullOutput())
-    def is_quiet(self):  # type: () -> bool
-        return False
-    def is_verbose(self):  # type: () -> bool
-        return False
-    def is_very_verbose(self):  # type: () -> bool
-        return False
-    def is_debug(self):  # type: () -> bool
-        return False
-    def writeln(self, *args, **kwargs):
-        pass
-    def write(self, *args, **kwargs):
-        pass
-    def new_line(self, *args, **kwargs):
-        pass
--- a/poetry/io/raw_argv_input.py
+++ b/poetry/io/raw_argv_input.py
-import sys
-from cleo.inputs import ArgvInput
-class RawArgvInput(ArgvInput):
-    def parse(self):
-        self._parsed = self._tokens
-        while True:
-            try:
-                token = self._parsed.pop(0)
-            except IndexError:
-                break
-            self.parse_argument(token)
--- a/poetry/masonry/api.py
+++ b/poetry/masonry/api.py
@@ -4,8 +4,9 @@ PEP-517 compliant buildsystem API
 import logging
 import sys
+from clikit.io import NullIO
 from poetry.poetry import Poetry
-from poetry.io import NullIO
 from poetry.utils._compat import Path
 from poetry.utils._compat import unicode
 from poetry.utils.env import SystemEnv

--- a/poetry/masonry/builders/builder.py
+++ b/poetry/masonry/builders/builder.py
@@ -8,6 +8,8 @@ from contextlib import contextmanager
 from typing import Set
 from typing import Union
+from clikit.api.io.flags import VERY_VERBOSE
 from poetry.utils._compat import Path
 from poetry.utils._compat import basestring
 from poetry.utils._compat import lru_cache
@@ -98,26 +100,24 @@ class Builder(object):
                    # Skip duplicates
                    continue
-                self._io.writeln(
+                self._io.write_line(
-                    " - Adding: <comment>{}</comment>".format(str(file)),
+                    " - Adding: <comment>{}</comment>".format(str(file)), VERY_VERBOSE
-                    verbosity=self._io.VERBOSITY_VERY_VERBOSE,
                )
                to_add.append(file)
        # Include project files
-        self._io.writeln(
+        self._io.write_line(
-            " - Adding: <comment>pyproject.toml</comment>",
+            " - Adding: <comment>pyproject.toml</comment>", VERY_VERBOSE
-            verbosity=self._io.VERBOSITY_VERY_VERBOSE,
        )
        to_add.append(Path("pyproject.toml"))
        # If a license file exists, add it
        for license_file in self._path.glob("LICENSE*"):
-            self._io.writeln(
+            self._io.write_line(
                " - Adding: <comment>{}</comment>".format(
                    license_file.relative_to(self._path)
                ),
-                verbosity=self._io.VERBOSITY_VERY_VERBOSE,
+                VERY_VERBOSE,
            )
            to_add.append(license_file.relative_to(self._path))
@@ -126,11 +126,11 @@ class Builder(object):
        if "readme" in self._poetry.local_config:
            readme = self._path / self._poetry.local_config["readme"]
            if readme.exists():
-                self._io.writeln(
+                self._io.write_line(
                    " - Adding: <comment>{}</comment>".format(
                        readme.relative_to(self._path)
                    ),
-                    verbosity=self._io.VERBOSITY_VERY_VERBOSE,
+                    VERY_VERBOSE,
                )
                to_add.append(readme.relative_to(self._path))

--- a/poetry/masonry/builders/complete.py
+++ b/poetry/masonry/builders/complete.py
@@ -17,7 +17,7 @@ class CompleteBuilder(Builder):
        sdist_builder = SdistBuilder(self._poetry, self._env, self._io)
        sdist_file = sdist_builder.build()
-        self._io.writeln("")
+        self._io.write_line("")
        dist_dir = self._path / "dist"
        with self.unpacked_tarball(sdist_file) as tmpdir:

--- a/poetry/masonry/builders/sdist.py
+++ b/poetry/masonry/builders/sdist.py
@@ -54,7 +54,7 @@ Author-email: {author_email}
 class SdistBuilder(Builder):
    def build(self, target_dir=None):  # type: (Path) -> Path
-        self._io.writeln(" - Building <info>sdist</info>")
+        self._io.write_line(" - Building <info>sdist</info>")
        if target_dir is None:
            target_dir = self._path / "dist"
@@ -101,7 +101,7 @@ class SdistBuilder(Builder):
            tar.close()
            gz.close()
-        self._io.writeln(" - Built <fg=cyan>{}</>".format(target.name))
+        self._io.write_line(" - Built <fg=cyan>{}</>".format(target.name))
        return target

--- a/poetry/masonry/builders/wheel.py
+++ b/poetry/masonry/builders/wheel.py
@@ -13,6 +13,8 @@ from base64 import urlsafe_b64encode
 from io import StringIO
 from typing import Set
+from clikit.api.io.flags import VERY_VERBOSE
 from poetry.__version__ import __version__
 from poetry.semver import parse_constraint
@@ -56,7 +58,7 @@ class WheelBuilder(Builder):
        cls.make_in(poetry, env, io)
    def build(self):
-        self._io.writeln(" - Building <info>wheel</info>")
+        self._io.write_line(" - Building <info>wheel</info>")
        dist_dir = self._target_dir
        if not dist_dir.exists():
@@ -77,7 +79,7 @@ class WheelBuilder(Builder):
            wheel_path.unlink()
        shutil.move(temp_path, str(wheel_path))
-        self._io.writeln(" - Built <fg=cyan>{}</>".format(self.wheel_filename))
+        self._io.write_line(" - Built <fg=cyan>{}</>".format(self.wheel_filename))
    def _build(self, wheel):
        if self._package.build:
@@ -113,9 +115,8 @@ class WheelBuilder(Builder):
                if rel_path in wheel.namelist():
                    continue
-                self._io.writeln(
+                self._io.write_line(
-                    " - Adding: <comment>{}</comment>".format(rel_path),
+                    " - Adding: <comment>{}</comment>".format(rel_path), VERY_VERBOSE
-                    verbosity=self._io.VERBOSITY_VERY_VERBOSE,
                )
                self._add_file(wheel, pkg, rel_path)
@@ -149,9 +150,8 @@ class WheelBuilder(Builder):
                    # Skip duplicates
                    continue
-                self._io.writeln(
+                self._io.write_line(
-                    " - Adding: <comment>{}</comment>".format(str(file)),
+                    " - Adding: <comment>{}</comment>".format(str(file)), VERY_VERBOSE
-                    verbosity=self._io.VERBOSITY_VERY_VERBOSE,
                )
                to_add.append((file, rel_file))

--- a/poetry/masonry/publishing/publisher.py
+++ b/poetry/masonry/publishing/publisher.py
@@ -23,7 +23,7 @@ class Publisher:
    def publish(self, repository_name, username, password):
        if repository_name:
-            self._io.writeln(
+            self._io.write_line(
                "Publishing <info>{}</info> (<comment>{}</comment>) "
                "to <fg=cyan>{}</>".format(
                    self._package.pretty_name,
@@ -32,7 +32,7 @@ class Publisher:
                )
            )
        else:
-            self._io.writeln(
+            self._io.write_line(
                "Publishing <info>{}</info> (<comment>{}</comment>) "
                "to <fg=cyan>PyPI</>".format(
                    self._package.pretty_name, self._package.pretty_version

--- a/poetry/masonry/publishing/uploader.py
+++ b/poetry/masonry/publishing/uploader.py
@@ -213,7 +213,7 @@ class Uploader:
                ("content", (file.name, fp, "application/octet-stream"))
            )
            encoder = MultipartEncoder(data_to_send)
-            bar = self._io.create_progress_bar(encoder.len)
+            bar = self._io.progress_bar(encoder.len)
            bar.set_format(
                " - Uploading <info>{0}</> <comment>%percent%%</>".format(file.name)
            )
@@ -233,7 +233,7 @@ class Uploader:
            if resp.ok:
                bar.finish()
-                self._io.writeln("")
+                self._io.write_line("")
            else:
                self._io.overwrite("")

--- a/poetry/puzzle/provider.py
+++ b/poetry/puzzle/provider.py
@@ -3,16 +3,13 @@ import logging
 import os
 import pkginfo
 import re
-import shutil
 import time
-from cleo import ProgressIndicator
+from clikit.ui.components import ProgressIndicator
 from contextlib import contextmanager
 from tempfile import mkdtemp
 from typing import List
-from poetry.io import NullIO
 from poetry.packages import Dependency
 from poetry.packages import DependencyPackage
 from poetry.packages import DirectoryDependency
@@ -46,20 +43,8 @@ logger = logging.getLogger(__name__)
 class Indicator(ProgressIndicator):
-    def __init__(self, output):
-        super(Indicator, self).__init__(output)
-        self.format = "%message% <fg=black;options=bold>(%elapsed:2s%)</>"
-    @contextmanager
-    def auto(self):
-        message = "<info>Resolving dependencies</info>..."
-        with super(Indicator, self).auto(message, message):
-            yield
    def _formatter_elapsed(self):
-        elapsed = time.time() - self.start_time
+        elapsed = time.time() - self._start_time
        return "{:.1f}s".format(elapsed)
@@ -625,14 +610,8 @@ class Provider:
        return package
-    # UI
-    @property
-    def output(self):
-        return self._io
    def debug(self, message, depth=0):
-        if not (self.output.is_very_verbose() or self.output.is_debug()):
+        if not (self._io.is_very_verbose() or self._io.is_debug()):
            return
        if message.startswith("fact:"):
@@ -717,17 +696,22 @@ class Provider:
                + "\n"
            )
-            self.output.write(debug_info)
+            self._io.write(debug_info)
    @contextmanager
    def progress(self):
-        if not self._io.is_decorated() or self.is_debugging():
+        if not self._io.output.supports_ansi() or self.is_debugging():
-            self.output.writeln("Resolving dependencies...")
+            self._io.write_line("Resolving dependencies...")
            yield
        else:
-            indicator = Indicator(self._io)
+            indicator = Indicator(
+                self._io, "{message} <fg=black;options=bold>({elapsed:2s})</>"
+            )
-            with indicator.auto():
+            with indicator.auto(
+                "<info>Resolving dependencies...</info>",
+                "<info>Resolving dependencies...</info>",
+            ):
                yield
        self._in_progress = False
--- a/poetry/utils/env.py
+++ b/poetry/utils/env.py
@@ -13,6 +13,8 @@ from typing import Dict
 from typing import Optional
 from typing import Tuple
+from clikit.api.io import IO
 from poetry.config import Config
 from poetry.locations import CACHE_DIR
 from poetry.utils._compat import Path
@@ -235,7 +237,7 @@ class Env(object):
        if not venv.exists():
            if create_venv is False:
-                io.writeln(
+                io.write_line(
                    "<fg=black;bg=yellow>"
                    "Skipping virtualenv creation, "
                    "as specified in config file."
@@ -244,14 +246,14 @@ class Env(object):
                return SystemEnv(Path(sys.prefix))
-            io.writeln(
+            io.write_line(
                "Creating virtualenv <info>{}</> in {}".format(name, str(venv_path))
            )
            cls.build_venv(str(venv))
        else:
            if io.is_very_verbose():
-                io.writeln("Virtualenv <info>{}</> already exists.".format(name))
+                io.write_line("Virtualenv <info>{}</> already exists.".format(name))
        # venv detection:
        # stdlib venv may symlink sys.executable, so we can't use realpath.
@@ -528,11 +530,17 @@ class NullEnv(SystemEnv):
        self._execute = execute
        self.executed = []
-    def run(self, bin, *args):
+    def run(self, bin, *args, **kwargs):
+        self.executed.append([bin] + list(args))
+        if self._execute:
+            return super(NullEnv, self).run(bin, *args, **kwargs)
+    def execute(self, bin, *args, **kwargs):
        self.executed.append([bin] + list(args))
        if self._execute:
-            return super(NullEnv, self).run(bin, *args)
+            return super(NullEnv, self).execute(bin, *args, **kwargs)
    def _bin(self, bin):
        return bin

--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,7 +23,7 @@ classifiers = [
 # Requirements
 [tool.poetry.dependencies]
 python = "~2.7 || ^3.4"
-cleo = "^0.6.7"
+cleo = "^0.7.2"
 requests = "^2.18"
 cachy = "^0.2"
 requests-toolbelt = "^0.8.0"

--- a/sonnet
+++ b/sonnet
@@ -18,7 +18,7 @@ class MakeReleaseCommand(Command):
    """
    Makes a self-contained package of Poetry.
-    make:release
+    release
        {--P|python=?* : Python version to use}
    """
@@ -198,9 +198,22 @@ class MakeReleaseCommand(Command):
        self.line("")
-app = Application("Sonnet")
+class MakeCommand(Command):
+    """
+    Build poetry releases.
+    make
+    """
+    commands = [MakeReleaseCommand()]
+    def handle(self):
+        return self.call("help", self.config.name)
+app = Application("sonnet")
-app.add(MakeReleaseCommand())
+app.add(MakeCommand())
 if __name__ == "__main__":
    app.run()
--- a/tests/console/commands/debug/test_resolve.py
+++ b/tests/console/commands/debug/test_resolve.py
@@ -4,7 +4,7 @@ from tests.helpers import get_package
 def test_debug_resolve_gives_resolution_results(app, repo):
-    command = app.find("debug:resolve")
+    command = app.find("debug resolve")
    tester = CommandTester(command)
    cachy2 = get_package("cachy", "0.2.0")
@@ -14,7 +14,7 @@ def test_debug_resolve_gives_resolution_results(app, repo):
    repo.add_package(cachy2)
    repo.add_package(get_package("msgpack-python", "0.5.3"))
-    tester.execute([("command", command.get_name()), ("package", ["cachy"])])
+    tester.execute("cachy")
    expected = """\
 Resolving dependencies...
@@ -25,11 +25,11 @@ Resolution results:
  - cachy (0.2.0)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_debug_resolve_tree_option_gives_the_dependency_tree(app, repo):
-    command = app.find("debug:resolve")
+    command = app.find("debug resolve")
    tester = CommandTester(command)
    cachy2 = get_package("cachy", "0.2.0")
@@ -39,9 +39,7 @@ def test_debug_resolve_tree_option_gives_the_dependency_tree(app, repo):
    repo.add_package(cachy2)
    repo.add_package(get_package("msgpack-python", "0.5.3"))
-    tester.execute(
+    tester.execute("cachy --tree")
-        [("command", command.get_name()), ("package", ["cachy"]), ("--tree", True)]
-    )
    expected = """\
 Resolving dependencies...
@@ -52,22 +50,17 @@ cachy 0.2.0
 `-- msgpack-python >=0.5 <0.6
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_debug_resolve_git_dependency(app, repo):
    repo.add_package(get_package("pendulum", "2.0.3"))
    repo.add_package(get_package("cleo", "0.6.5"))
-    command = app.find("debug:resolve")
+    command = app.find("debug resolve")
    tester = CommandTester(command)
-    tester.execute(
+    tester.execute("git+https://github.com/demo/demo.git")
-        [
-            ("command", command.get_name()),
-            ("package", ["git+https://github.com/demo/demo.git"]),
-        ]
-    )
    expected = """\
 Resolving dependencies...
@@ -78,4 +71,4 @@ Resolution results:
  - demo (0.1.2)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
--- a/tests/console/commands/test_about.py
+++ b/tests/console/commands/test_about.py
@@ -5,14 +5,13 @@ def test_about(app):
    command = app.find("about")
    tester = CommandTester(command)
-    tester.execute([("command", command.get_name())])
+    tester.execute()
    expected = """\
 Poetry - Package Management for Python
 Poetry is a dependency manager tracking local dependencies of your projects and libraries.
 See https://github.com/sdispater/poetry for more information.
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
--- a/tests/console/commands/test_add.py
+++ b/tests/console/commands/test_add.py
@@ -13,7 +13,7 @@ def test_add_no_constraint(app, repo, installer):
    repo.add_package(get_package("cachy", "0.1.0"))
    repo.add_package(get_package("cachy", "0.2.0"))
-    tester.execute([("command", command.get_name()), ("name", ["cachy"])])
+    tester.execute("cachy")
    expected = """\
 Using version ^0.2.0 for cachy
@@ -29,7 +29,7 @@ Writing lock file
  - Installing cachy (0.2.0)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 1
@@ -46,7 +46,7 @@ def test_add_constraint(app, repo, installer):
    repo.add_package(get_package("cachy", "0.1.0"))
    repo.add_package(get_package("cachy", "0.2.0"))
-    tester.execute([("command", command.get_name()), ("name", ["cachy=0.1.0"])])
+    tester.execute("cachy=0.1.0")
    expected = """\
@@ -61,7 +61,7 @@ Writing lock file
  - Installing cachy (0.1.0)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 1
@@ -78,7 +78,7 @@ def test_add_constraint_dependencies(app, repo, installer):
    repo.add_package(cachy2)
    repo.add_package(get_package("msgpack-python", "0.5.3"))
-    tester.execute([("command", command.get_name()), ("name", ["cachy=0.2.0"])])
+    tester.execute("cachy=0.2.0")
    expected = """\
@@ -94,7 +94,7 @@ Writing lock file
  - Installing cachy (0.2.0)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 2
@@ -106,13 +106,7 @@ def test_add_git_constraint(app, repo, installer):
    repo.add_package(get_package("pendulum", "1.4.4"))
    repo.add_package(get_package("cleo", "0.6.5"))
-    tester.execute(
+    tester.execute("demo --git https://github.com/demo/demo.git")
-        [
-            ("command", command.get_name()),
-            ("name", ["demo"]),
-            ("--git", "https://github.com/demo/demo.git"),
-        ]
-    )
    expected = """\
@@ -128,7 +122,7 @@ Writing lock file
  - Installing demo (0.1.2 9cf87a2)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 2
@@ -146,13 +140,7 @@ def test_add_git_constraint_with_poetry(app, repo, installer):
    repo.add_package(get_package("pendulum", "1.4.4"))
-    tester.execute(
+    tester.execute("demo --git https://github.com/demo/pyproject-demo.git")
-        [
-            ("command", command.get_name()),
-            ("name", ["demo"]),
-            ("--git", "https://github.com/demo/pyproject-demo.git"),
-        ]
-    )
    expected = """\
@@ -168,7 +156,7 @@ Writing lock file
  - Installing demo (0.1.2 9cf87a2)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 2
@@ -179,13 +167,7 @@ def test_add_file_constraint_wheel(app, repo, installer):
    repo.add_package(get_package("pendulum", "1.4.4"))
-    tester.execute(
+    tester.execute("demo --path ../distributions/demo-0.1.0-py2.py3-none-any.whl")
-        [
-            ("command", command.get_name()),
-            ("name", ["demo"]),
-            ("--path", "../distributions/demo-0.1.0-py2.py3-none-any.whl"),
-        ]
-    )
    expected = """\
@@ -201,7 +183,7 @@ Writing lock file
  - Installing demo (0.1.0 ../distributions/demo-0.1.0-py2.py3-none-any.whl)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 2
@@ -219,13 +201,7 @@ def test_add_file_constraint_sdist(app, repo, installer):
    repo.add_package(get_package("pendulum", "1.4.4"))
-    tester.execute(
+    tester.execute("demo --path ../distributions/demo-0.1.0.tar.gz")
-        [
-            ("command", command.get_name()),
-            ("name", ["demo"]),
-            ("--path", "../distributions/demo-0.1.0.tar.gz"),
-        ]
-    )
    expected = """\
@@ -241,7 +217,7 @@ Writing lock file
  - Installing demo (0.1.0 ../distributions/demo-0.1.0.tar.gz)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 2
@@ -266,13 +242,7 @@ def test_add_constraint_with_extras(app, repo, installer):
    repo.add_package(cachy2)
    repo.add_package(get_package("msgpack-python", "0.5.3"))
-    tester.execute(
+    tester.execute("cachy=0.2.0 --extras msgpack")
-        [
-            ("command", command.get_name()),
-            ("name", ["cachy=0.2.0"]),
-            ("--extras", ["msgpack"]),
-        ]
-    )
    expected = """\
@@ -288,7 +258,7 @@ Writing lock file
  - Installing cachy (0.2.0)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 2
@@ -310,13 +280,7 @@ def test_add_constraint_with_python(app, repo, installer):
    repo.add_package(get_package("cachy", "0.1.0"))
    repo.add_package(cachy2)
-    tester.execute(
+    tester.execute("cachy=0.2.0 --python >=2.7")
-        [
-            ("command", command.get_name()),
-            ("name", ["cachy=0.2.0"]),
-            ("--python", ">=2.7"),
-        ]
-    )
    expected = """\
@@ -331,7 +295,7 @@ Writing lock file
  - Installing cachy (0.2.0)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 1
@@ -351,13 +315,7 @@ def test_add_constraint_with_platform(app, repo, installer):
    repo.add_package(get_package("cachy", "0.1.0"))
    repo.add_package(cachy2)
-    tester.execute(
+    tester.execute("cachy=0.2.0 --platform {}".format(platform))
-        [
-            ("command", command.get_name()),
-            ("name", ["cachy=0.2.0"]),
-            ("--platform", platform),
-        ]
-    )
    expected = """\
@@ -372,7 +330,7 @@ Writing lock file
  - Installing cachy (0.2.0)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 1
@@ -392,9 +350,7 @@ def test_add_to_section_that_does_no_exist_yet(app, repo, installer):
    repo.add_package(get_package("cachy", "0.1.0"))
    repo.add_package(get_package("cachy", "0.2.0"))
-    tester.execute(
+    tester.execute("cachy --dev")
-        [("command", command.get_name()), ("name", ["cachy"]), ("--dev", True)]
-    )
    expected = """\
 Using version ^0.2.0 for cachy
@@ -410,7 +366,7 @@ Writing lock file
  - Installing cachy (0.2.0)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 1
@@ -427,7 +383,7 @@ def test_add_should_not_select_prereleases(app, repo, installer):
    repo.add_package(get_package("pyyaml", "3.13"))
    repo.add_package(get_package("pyyaml", "4.2b2"))
-    tester.execute([("command", command.get_name()), ("name", ["pyyaml"])])
+    tester.execute("pyyaml")
    expected = """\
 Using version ^3.13 for pyyaml
@@ -443,7 +399,7 @@ Writing lock file
  - Installing pyyaml (3.13)
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
    assert len(installer.installs) == 1

--- a/tests/console/commands/test_check.py
+++ b/tests/console/commands/test_check.py
@@ -9,13 +9,13 @@ def test_check_valid(app):
    command = app.find("check")
    tester = CommandTester(command)
-    tester.execute([("command", command.get_name())])
+    tester.execute()
    expected = """\
 All set!
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_check_invalid(app):
@@ -25,7 +25,7 @@ def test_check_invalid(app):
    command = app.find("check")
    tester = CommandTester(command)
-    tester.execute([("command", command.get_name())])
+    tester.execute()
    if PY2:
        expected = """\
@@ -40,4 +40,4 @@ Error: INVALID is not a valid license
 Warning: A wildcard Python dependency is ambiguous. Consider specifying a more explicit one.
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
--- a/tests/console/commands/test_config.py
+++ b/tests/console/commands/test_config.py
@@ -26,10 +26,10 @@ def setup(config):
 def test_list_displays_default_value_if_not_set(app, config):
    command = app.find("config")
-    command._config = Config(config.file)
+    command._settings_config = Config(config.file)
    tester = CommandTester(command)
-    tester.execute([("command", command.get_name()), ("--list", True)])
+    tester.execute("--list")
    expected = """settings.virtualenvs.create = true
 settings.virtualenvs.in-project = false
@@ -37,24 +37,18 @@ settings.virtualenvs.path = "."
 repositories = {}
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_list_displays_set_get_setting(app, config):
    command = app.find("config")
-    command._config = Config(config.file)
+    command._settings_config = Config(config.file)
    tester = CommandTester(command)
-    tester.execute(
+    tester.execute("settings.virtualenvs.create false")
-        [
-            ("command", command.get_name()),
-            ("key", "settings.virtualenvs.create"),
-            ("value", ["false"]),
-        ]
-    )
-    command._config = Config(config.file)
+    command._settings_config = Config(config.file)
-    tester.execute([("command", command.get_name()), ("--list", True)])
+    tester.execute("--list")
    expected = """settings.virtualenvs.create = false
 settings.virtualenvs.in-project = false
@@ -62,19 +56,17 @@ settings.virtualenvs.path = "."
 repositories = {}
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_display_single_setting(app, config):
    command = app.find("config")
-    command._config = Config(config.file)
+    command._settings_config = Config(config.file)
    tester = CommandTester(command)
-    tester.execute(
+    tester.execute("settings.virtualenvs.create")
-        [("command", command.get_name()), ("key", "settings.virtualenvs.create")]
-    )
    expected = """true
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
--- a/tests/console/commands/test_export.py
+++ b/tests/console/commands/test_export.py
@@ -69,7 +69,7 @@ def test_export_exports_requirements_txt_file_locks_if_no_lock_file(app, repo):
    repo.add_package(get_package("foo", "1.0.0"))
-    tester.execute([("command", command.get_name()), ("--format", "requirements.txt")])
+    tester.execute("--format requirements.txt")
    requirements = app.poetry.file.parent / "requirements.txt"
    assert requirements.exists()
@@ -84,7 +84,7 @@ foo==1.0.0
 """
    assert expected == content
-    assert "The lock file does not exist. Locking." in tester.get_display(True)
+    assert "The lock file does not exist. Locking." in tester.io.fetch_output()
 def test_export_exports_requirements_txt_uses_lock_file(app, repo):
@@ -92,14 +92,14 @@ def test_export_exports_requirements_txt_uses_lock_file(app, repo):
    command = app.find("lock")
    tester = CommandTester(command)
-    tester.execute([("command", "lock")])
+    tester.execute()
    assert app.poetry.locker.lock.exists()
    command = app.find("export")
    tester = CommandTester(command)
-    tester.execute([("command", command.get_name()), ("--format", "requirements.txt")])
+    tester.execute("--format requirements.txt")
    requirements = app.poetry.file.parent / "requirements.txt"
    assert requirements.exists()
@@ -114,7 +114,7 @@ foo==1.0.0
 """
    assert expected == content
-    assert "The lock file does not exist. Locking." not in tester.get_display(True)
+    assert "The lock file does not exist. Locking." not in tester.io.fetch_output()
 def test_export_fails_on_invalid_format(app, repo):
@@ -122,7 +122,7 @@ def test_export_fails_on_invalid_format(app, repo):
    command = app.find("lock")
    tester = CommandTester(command)
-    tester.execute([("command", "lock")])
+    tester.execute()
    assert app.poetry.locker.lock.exists()
@@ -130,4 +130,4 @@ def test_export_fails_on_invalid_format(app, repo):
    tester = CommandTester(command)
    with pytest.raises(ValueError):
-        tester.execute([("command", command.get_name()), ("--format", "invalid")])
+        tester.execute("--format invalid")
--- a/tests/console/commands/test_init.py
+++ b/tests/console/commands/test_init.py
@@ -14,8 +14,7 @@ def test_basic_interactive(app, mocker, poetry):
    p.return_value = Path(__file__)
    tester = CommandTester(command)
-    tester.set_inputs(
+    inputs = [
-        [
        "my-package",  # Package name
        "1.2.3",  # Version
        "This is a description",  # Description
@@ -26,10 +25,8 @@ def test_basic_interactive(app, mocker, poetry):
        "n",  # Interactive dev packages
        "\n",  # Generate
    ]
-    )
+    tester.execute(inputs="\n".join(inputs))
-    tester.execute([("command", command.name)])
-    output = tester.get_display(True)
    expected = """\
 [tool.poetry]
 name = "my-package"
@@ -44,7 +41,7 @@ python = "~2.7 || ^3.6"
 [tool.poetry.dev-dependencies]
 """
-    assert expected in output
+    assert expected in tester.io.fetch_output()
 def test_interactive_with_dependencies(app, repo, mocker, poetry):
@@ -59,8 +56,7 @@ def test_interactive_with_dependencies(app, repo, mocker, poetry):
    p.return_value = Path(__file__).parent
    tester = CommandTester(command)
-    tester.set_inputs(
+    inputs = [
-        [
        "my-package",  # Package name
        "1.2.3",  # Version
        "This is a description",  # Description
@@ -79,10 +75,8 @@ def test_interactive_with_dependencies(app, repo, mocker, poetry):
        "",
        "\n",  # Generate
    ]
-    )
+    tester.execute(inputs="\n".join(inputs))
-    tester.execute([("command", command.name)])
-    output = tester.get_display(True)
    expected = """\
 [tool.poetry]
 name = "my-package"
@@ -99,7 +93,7 @@ pendulum = "^2.0"
 pytest = "^3.6"
 """
-    assert expected in output
+    assert expected in tester.io.fetch_output()
 def test_empty_license(app, mocker, poetry):
@@ -111,8 +105,7 @@ def test_empty_license(app, mocker, poetry):
    p.return_value = Path(__file__)
    tester = CommandTester(command)
-    tester.set_inputs(
+    inputs = [
-        [
        "my-package",  # Package name
        "1.2.3",  # Version
        "",  # Description
@@ -123,10 +116,8 @@ def test_empty_license(app, mocker, poetry):
        "n",  # Interactive dev packages
        "\n",  # Generate
    ]
-    )
+    tester.execute(inputs="\n".join(inputs))
-    tester.execute([("command", command.name)])
-    output = tester.get_display(True)
    expected = """\
 [tool.poetry]
 name = "my-package"
@@ -140,4 +131,4 @@ python = "^3.7"
 [tool.poetry.dev-dependencies]
 """
-    assert expected in output
+    assert expected in tester.io.fetch_output()
--- a/tests/console/commands/test_run.py
+++ b/tests/console/commands/test_run.py
+from cleo.testers import CommandTester
+from poetry.utils.env import MockEnv
+def test_run_passes_all_args(app, mocker):
+    env = MockEnv(is_venv=True)
+    mocker.patch("poetry.utils.env.Env.get", return_value=env)
+    command = app.find("run")
+    tester = CommandTester(command)
+    tester.execute("python -V")
+    assert [["python", "-V"]] == env.executed
--- a/tests/console/commands/test_show.py
+++ b/tests/console/commands/test_show.py
@@ -65,7 +65,7 @@ def test_show_basic_with_installed_packages(app, poetry, installed):
        }
    )
-    tester.execute([("command", command.get_name())])
+    tester.execute()
    expected = """\
 cachy    0.1.0 Cachy package
@@ -73,7 +73,7 @@ pendulum 2.0.0 Pendulum package
 pytest   3.7.3 Pytest package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_show_basic_with_not_installed_packages_non_decorated(app, poetry, installed):
@@ -120,14 +120,14 @@ def test_show_basic_with_not_installed_packages_non_decorated(app, poetry, insta
        }
    )
-    tester.execute([("command", command.get_name())])
+    tester.execute()
    expected = """\
 cachy        0.1.0 Cachy package
 pendulum (!) 2.0.0 Pendulum package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_show_basic_with_not_installed_packages_decorated(app, poetry, installed):
@@ -174,14 +174,14 @@ def test_show_basic_with_not_installed_packages_decorated(app, poetry, installed
        }
    )
-    tester.execute([("command", command.get_name())], {"decorated": True})
+    tester.execute(decorated=True)
    expected = """\
 \033[32mcachy   \033[0m \033[36m0.1.0\033[0m Cachy package
 \033[31mpendulum\033[0m \033[36m2.0.0\033[0m Pendulum package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_show_latest_non_decorated(app, poetry, installed, repo):
@@ -239,14 +239,14 @@ def test_show_latest_non_decorated(app, poetry, installed, repo):
        }
    )
-    tester.execute([("command", command.get_name()), ("--latest", True)])
+    tester.execute("--latest")
    expected = """\
 cachy    0.1.0 0.2.0 Cachy package
 pendulum 2.0.0 2.0.1 Pendulum package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_show_latest_decorated(app, poetry, installed, repo):
@@ -304,16 +304,14 @@ def test_show_latest_decorated(app, poetry, installed, repo):
        }
    )
-    tester.execute(
+    tester.execute("--latest", decorated=True)
-        [("command", command.get_name()), ("--latest", True)], {"decorated": True}
-    )
    expected = """\
 \033[32mcachy   \033[0m \033[36m0.1.0\033[0m \033[33m0.2.0\033[0m Cachy package
 \033[32mpendulum\033[0m \033[36m2.0.0\033[0m \033[31m2.0.1\033[0m Pendulum package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_show_outdated(app, poetry, installed, repo):
@@ -368,13 +366,13 @@ def test_show_outdated(app, poetry, installed, repo):
        }
    )
-    tester.execute([("command", command.get_name()), ("--outdated", True)])
+    tester.execute("--outdated")
    expected = """\
 cachy 0.1.0 0.2.0 Cachy package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_show_outdated_formatting(app, poetry, installed, repo):
@@ -432,14 +430,14 @@ def test_show_outdated_formatting(app, poetry, installed, repo):
        }
    )
-    tester.execute([("command", command.get_name()), ("--outdated", True)])
+    tester.execute("--outdated")
    expected = """\
 cachy    0.1.0 0.2.0 Cachy package
 pendulum 2.0.0 2.0.1 Pendulum package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 @pytest.mark.parametrize("project_directory", ["project_with_local_dependencies"])
@@ -533,13 +531,13 @@ def test_show_outdated_local_dependencies(app, poetry, installed, repo):
        }
    )
-    tester.execute([("command", command.get_name()), ("--outdated", True)])
+    tester.execute("--outdated")
    expected = """\
 cachy      0.1.0                       0.2.0                      
 my-package 0.1.1 ../project_with_setup 0.1.2 ../project_with_setup
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 @pytest.mark.parametrize("project_directory", ["project_with_git_dev_dependency"])
@@ -614,14 +612,14 @@ def test_show_outdated_git_dev_dependency(app, poetry, installed, repo):
        }
    )
-    tester.execute([("command", command.get_name()), ("--outdated", True)])
+    tester.execute("--outdated")
    expected = """\
 cachy 0.1.0         0.2.0         Cachy package
 demo  0.1.1 9cf87a2 0.1.2 9cf87a2 Demo package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 @pytest.mark.parametrize("project_directory", ["project_with_git_dev_dependency"])
@@ -696,15 +694,13 @@ def test_show_outdated_no_dev_git_dev_dependency(app, poetry, installed, repo):
        }
    )
-    tester.execute(
+    tester.execute("--outdated --no-dev")
-        [("command", command.get_name()), ("--outdated", True), ("--no-dev", True)]
-    )
    expected = """\
 cachy 0.1.0 0.2.0 Cachy package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_show_hides_incompatible_package(app, poetry, installed, repo):
@@ -753,13 +749,13 @@ def test_show_hides_incompatible_package(app, poetry, installed, repo):
        }
    )
-    tester.execute([("command", command.get_name())])
+    tester.execute()
    expected = """\
 pendulum 2.0.0 Pendulum package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_show_all_shows_incompatible_package(app, poetry, installed, repo):
@@ -808,14 +804,14 @@ def test_show_all_shows_incompatible_package(app, poetry, installed, repo):
        }
    )
-    tester.execute([("command", command.get_name()), ("--all", True)])
+    tester.execute("--all")
    expected = """\
 cachy     0.1.0 Cachy package
 pendulum  2.0.0 Pendulum package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
 def test_show_non_dev_with_basic_installed_packages(app, poetry, installed):
@@ -879,11 +875,66 @@ def test_show_non_dev_with_basic_installed_packages(app, poetry, installed):
        }
    )
-    tester.execute([("command", command.get_name()), ("--no-dev", True)])
+    tester.execute("--no-dev")
    expected = """\
 cachy    0.1.0 Cachy package
 pendulum 2.0.0 Pendulum package
 """
-    assert tester.get_display(True) == expected
+    assert expected == tester.io.fetch_output()
+def test_show_tree(app, poetry, installed):
+    command = app.find("show")
+    tester = CommandTester(command)
+    poetry.package.add_dependency("cachy", "^0.2.0")
+    cachy2 = get_package("cachy", "0.2.0")
+    cachy2.add_dependency("msgpack-python", ">=0.5 <0.6")
+    installed.add_package(cachy2)
+    poetry.locker.mock_lock_data(
+        {
+            "package": [
+                {
+                    "name": "cachy",
+                    "version": "0.2.0",
+                    "description": "",
+                    "category": "main",
+                    "optional": False,
+                    "platform": "*",
+                    "python-versions": "*",
+                    "checksum": [],
+                    "dependencies": {"msgpack-python": ">=0.5 <0.6"},
+                },
+                {
+                    "name": "msgpack-python",
+                    "version": "0.5.1",
+                    "description": "",
+                    "category": "main",
+                    "optional": False,
+                    "platform": "*",
+                    "python-versions": "*",
+                    "checksum": [],
+                },
+            ],
+            "metadata": {
+                "python-versions": "*",
+                "platform": "*",
+                "content-hash": "123456789",
+                "hashes": {"cachy": [], "msgpack-python": []},
+            },
+        }
+    )
+    tester.execute("--tree")
+    expected = """\
+cachy 0.2.0
+`-- msgpack-python >=0.5 <0.6
+"""
+    assert expected == tester.io.fetch_output()
--- a/tests/installation/test_installer.py
+++ b/tests/installation/test_installer.py
@@ -4,9 +4,10 @@ import sys
 import pytest
+from clikit.io import NullIO
 from poetry.installation import Installer as BaseInstaller
 from poetry.installation.noop_installer import NoopInstaller
-from poetry.io import NullIO
 from poetry.packages import Locker as BaseLocker
 from poetry.packages import ProjectPackage
 from poetry.repositories import Pool

--- a/tests/masonry/builders/test_builder.py
+++ b/tests/masonry/builders/test_builder.py
-from poetry.io import NullIO
+from clikit.io import NullIO
 from poetry.masonry.builders.builder import Builder
 from poetry.poetry import Poetry
 from poetry.utils._compat import Path

--- a/tests/masonry/builders/test_complete.py
+++ b/tests/masonry/builders/test_complete.py
@@ -9,8 +9,9 @@ import tarfile
 import zipfile
 import tempfile
+from clikit.io import NullIO
 from poetry import __version__
-from poetry.io import NullIO
 from poetry.masonry.builders import CompleteBuilder
 from poetry.poetry import Poetry
 from poetry.utils._compat import Path

--- a/tests/masonry/builders/test_sdist.py
+++ b/tests/masonry/builders/test_sdist.py
 # -*- coding: utf-8 -*-
 import ast
 import pytest
-import re
 import shutil
 import tarfile
 from email.parser import Parser
-from poetry.io import NullIO
+from clikit.io import NullIO
 from poetry.masonry.builders.sdist import SdistBuilder
 from poetry.masonry.utils.package_include import PackageInclude
 from poetry.packages import Package

--- a/tests/masonry/builders/test_wheel.py
+++ b/tests/masonry/builders/test_wheel.py
@@ -2,7 +2,8 @@ import pytest
 import shutil
 import zipfile
-from poetry.io import NullIO
+from clikit.io import NullIO
 from poetry.masonry.builders import WheelBuilder
 from poetry.poetry import Poetry
 from poetry.utils._compat import Path

--- a/tests/mixology/version_solver/conftest.py
+++ b/tests/mixology/version_solver/conftest.py
 import pytest
-from poetry.io import NullIO
+from clikit.io import NullIO
 from poetry.packages.project_package import ProjectPackage
 from poetry.repositories import Pool
 from poetry.repositories import Repository

--- a/tests/puzzle/test_provider.py
+++ b/tests/puzzle/test_provider.py
 import pytest
-from poetry.io import NullIO
+from clikit.io import NullIO
 from poetry.packages import ProjectPackage
 from poetry.packages.directory_dependency import DirectoryDependency
 from poetry.packages.file_dependency import FileDependency

--- a/tests/puzzle/test_solver.py
+++ b/tests/puzzle/test_solver.py
 import pytest
-from cleo.outputs.null_output import NullOutput
+from clikit.io import NullIO
-from cleo.styles import OutputStyle
 from poetry.packages import dependency_from_pep_508
 from poetry.packages import ProjectPackage
@@ -22,7 +21,7 @@ from tests.repositories.test_legacy_repository import (
 @pytest.fixture()
 def io():
-    return OutputStyle(NullOutput())
+    return NullIO()
 @pytest.fixture()