Use utils.pip for executor installs

poetry/installation/executor.py

@@ -24,6 +24,7 @@ from poetry.utils.env import EnvCommandError
 from poetry.utils.helpers import safe_rmtree
 from poetry.utils.pip import pip_editable_install
 
+from ..utils.pip import pip_install
 from .authenticator import Authenticator
 from .chef import Chef
 from .chooser import Chooser
@@ -475,12 +476,9 @@ class Executor(object):
             )
         )
         self._write(operation, message)
-
-        args = ["install", "--no-deps", str(archive)]
-        if operation.job_type == "update":
-            args.insert(2, "-U")
-
-        return self.run_pip(*args)
+        return pip_install(
+            str(archive), self._env, upgrade=operation.job_type == "update"
+        )
 
     def _update(self, operation: Union[Install, Update]) -> int:
         return self._install(operation)
@@ -538,8 +536,6 @@ class Executor(object):
         else:
             req = os.path.realpath(package.source_url)
 
-        args = ["install", "--no-deps", "-U"]
-
         pyproject = PyProjectTOML(os.path.join(req, "pyproject.toml"))
 
         if pyproject.is_poetry_project():
@@ -574,17 +570,12 @@ class Executor(object):
                 with builder.setup_py():
                     if package.develop:
                         return pip_editable_install(req, self._env)
-
-                    args.append(req)
-
-                    return self.run_pip(*args)
+                    return pip_install(req, self._env, upgrade=True)
 
         if package.develop:
             return pip_editable_install(req, self._env)
 
-        args.append(req)
-
-        return self.run_pip(*args)
+        return pip_install(req, self._env, upgrade=True)
 
     def _install_git(self, operation: Union[Install, Update]) -> int:
         from poetry.core.vcs import Git

poetry/utils/pip.py

+from pathlib import Path
+from typing import Union
+
 from poetry.exceptions import PoetryException
-from poetry.utils._compat import Path
 from poetry.utils.env import Env
 from poetry.utils.env import ephemeral_environment
 
 
 def pip_install(
-    path, environment, editable=False, deps=False, upgrade=False
-):  # type: (Path, Env, bool, bool, bool) -> None
+    path: Union[Path, str],
+    environment: Env,
+    editable: bool = False,
+    deps: bool = False,
+    upgrade: bool = False,
+) -> Union[int, str]:
     path = Path(path) if isinstance(path, str) else path
 
-    args = ["pip", "install", "--prefix", str(environment.path)]
+    args = ["install", "--prefix", str(environment.path)]
 
     if upgrade:
         args.append("--upgrade")
@@ -26,13 +32,19 @@ def pip_install(
 
     args.append(str(path))
 
+    if path.is_file() and path.suffix == ".whl":
+        return environment.run_pip(*args)
+
     with ephemeral_environment(
         executable=environment.python, pip=True, setuptools=True
     ) as env:
-        return env.run(*args)
+        return env.run(
+            "pip",
+            *args,
+        )
 
 
-def pip_editable_install(directory, environment):  # type: (Path, Env) -> None
+def pip_editable_install(directory: Path, environment: Env) -> Union[int, str]:
     return pip_install(
         path=directory, environment=environment, editable=True, deps=False, upgrade=True
     )

tests/installation/test_executor.py

@@ -13,6 +13,7 @@ from cleo.io.buffered_io import BufferedIO
 
 from poetry.config.config import Config
 from poetry.core.packages.package import Package
+from poetry.core.utils._compat import PY36
 from poetry.installation.executor import Executor
 from poetry.installation.operations import Install
 from poetry.installation.operations import Uninstall
@@ -69,7 +70,7 @@ def test_execute_executes_a_batch_of_operations(
     mocker, config, pool, io, tmp_dir, mock_file_downloads, env
 ):
     pip_editable_install = mocker.patch(
-        "poetry.installation.executor.pip_editable_install"
+        "poetry.installation.executor.pip_editable_install", unsafe=not PY36
     )
 
     config = Config()