Misc cleanups (#6256)

No functional change or fixes here, just tidier code:
* prefer Path.exists()
* typechecking - NormalizedNames from poetry-core
* clean up some unnecessary duplication
* minor refactor
* gather the pyproject.toml parsing into one block, save a level of indentation
* remove more dead code
* simplify handling of extras at command line
* more abstract types 

src/poetry/console/commands/add.py

@@ -180,10 +180,7 @@ The add command adds required packages to your <comment>pyproject.toml</> and in
             if self.option("extras"):
                 extras = []
                 for extra in self.option("extras"):
-                    if " " in extra:
-                        extras += [e.strip() for e in extra.split(" ")]
-                    else:
-                        extras.append(extra)
+                    extras += extra.split()
 
                 constraint["extras"] = self.option("extras")
 

src/poetry/console/commands/cache/clear.py

@@ -46,7 +46,7 @@ class CacheClearCommand(Command):
                     f"Add the --all option if you want to clear all {parts[0]} caches"
                 )
 
-            if not os.path.exists(cache_dir):
+            if not cache_dir.exists():
                 self.line(f"No cache entries for {parts[0]}")
                 return 0
 

src/poetry/console/commands/debug/resolve.py

@@ -65,10 +65,7 @@ class DebugResolveCommand(InitCommand):
                 assert isinstance(name, str)
                 extras = []
                 for extra in self.option("extras"):
-                    if " " in extra:
-                        extras += [e.strip() for e in extra.split(" ")]
-                    else:
-                        extras.append(extra)
+                    extras += extra.split()
 
                 constraint["extras"] = extras
 

src/poetry/console/commands/install.py

@@ -120,10 +120,7 @@ dependencies and not including the current project, run the command with the
         else:
             extras = []
             for extra in self.option("extras", []):
-                if " " in extra:
-                    extras += [e.strip() for e in extra.split(" ")]
-                else:
-                    extras.append(extra)
+                extras += extra.split()
 
         self.installer.extras(extras)
 

src/poetry/installation/executor.py

 from __future__ import annotations
 
+import contextlib
 import csv
 import itertools
 import json
@@ -542,7 +543,12 @@ class Executor:
 
         pyproject = PyProjectTOML(os.path.join(req, "pyproject.toml"))
 
+        package_poetry = None
         if pyproject.is_poetry_project():
+            with contextlib.suppress(RuntimeError):
+                package_poetry = Factory().create_poetry(pyproject.file.path.parent)
+
+        if package_poetry is not None:
             # Even if there is a build system specified
             # some versions of pip (< 19.0.0) don't understand it
             # so we need to check the version of pip to know
@@ -552,12 +558,6 @@ class Executor:
                 < self._env.pip_version.__class__.from_parts(19, 0, 0)
             )
 
-            try:
-                package_poetry = Factory().create_poetry(pyproject.file.path.parent)
-            except RuntimeError:
-                package_poetry = None
-
-            if package_poetry is not None:
             builder: Builder
             if package.develop and not package_poetry.package.build_script:
                 from poetry.masonry.builders.editable import EditableBuilder
@@ -577,16 +577,10 @@ class Executor:
                 # build-systems
                 # We also need it for non-PEP-517 packages
                 builder = SdistBuilder(package_poetry)
-
                 with builder.setup_py():
-                        if package.develop:
-                            return self.pip_install(req, upgrade=True, editable=True)
-                        return self.pip_install(req, upgrade=True)
-
-        if package.develop:
-            return self.pip_install(req, upgrade=True, editable=True)
+                    return self.pip_install(req, upgrade=True, editable=package.develop)
 
-        return self.pip_install(req, upgrade=True)
+        return self.pip_install(req, upgrade=True, editable=package.develop)
 
     def _install_git(self, operation: Install | Update) -> int:
         from poetry.vcs.git import Git

src/poetry/installation/installer.py

@@ -20,7 +20,6 @@ from poetry.utils.helpers import pluralize
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
-    from collections.abc import Sequence
 
     from cleo.io.io import IO
     from poetry.core.packages.project_package import ProjectPackage
@@ -465,7 +464,7 @@ class Installer:
         self._installer.remove(operation.package)
 
     def _populate_lockfile_repo(
-        self, repo: LockfileRepository, ops: Sequence[Operation]
+        self, repo: LockfileRepository, ops: Iterable[Operation]
     ) -> None:
         for op in ops:
             if isinstance(op, Uninstall):
@@ -509,7 +508,7 @@ class Installer:
 
         return ops
 
-    def _filter_operations(self, ops: Sequence[Operation], repo: Repository) -> None:
+    def _filter_operations(self, ops: Iterable[Operation], repo: Repository) -> None:
         extra_packages = self._get_extra_packages(repo)
         for op in ops:
             if isinstance(op, Update):

src/poetry/installation/pip_installer.py

 from __future__ import annotations
 
+import contextlib
 import os
 import tempfile
 import urllib.parse
@@ -225,19 +226,18 @@ class PipInstaller(BaseInstaller):
 
         pyproject = PyProjectTOML(os.path.join(req, "pyproject.toml"))
 
+        package_poetry = None
         if pyproject.is_poetry_project():
+            with contextlib.suppress(RuntimeError):
+                package_poetry = Factory().create_poetry(pyproject.file.path.parent)
+
+        if package_poetry is not None:
             # Even if there is a build system specified
             # some versions of pip (< 19.0.0) don't understand it
             # so we need to check the version of pip to know
             # if we can rely on the build system
             legacy_pip = self._env.pip_version < Version.from_parts(19, 0, 0)
 
-            try:
-                package_poetry = Factory().create_poetry(pyproject.file.path.parent)
-            except RuntimeError:
-                package_poetry = None
-
-            if package_poetry is not None:
             builder: Builder
             if package.develop and not package_poetry.package.build_script:
                 from poetry.masonry.builders.editable import EditableBuilder
@@ -259,22 +259,16 @@ class PipInstaller(BaseInstaller):
                 builder = SdistBuilder(package_poetry)
 
                 with builder.setup_py():
-                        if package.develop:
                     return pip_install(
                         path=req,
                         environment=self._env,
                         upgrade=True,
-                                editable=True,
-                            )
-                        return pip_install(
-                            path=req, environment=self._env, deps=False, upgrade=True
+                        editable=package.develop,
                     )
 
-        if package.develop:
         return pip_install(
-                path=req, environment=self._env, upgrade=True, editable=True
+            path=req, environment=self._env, upgrade=True, editable=package.develop
         )
-        return pip_install(path=req, environment=self._env, deps=False, upgrade=True)
 
     def install_git(self, package: Package) -> None:
         from poetry.core.packages.package import Package

src/poetry/packages/package_collection.py

@@ -7,7 +7,7 @@ from poetry.packages.dependency_package import DependencyPackage
 
 
 if TYPE_CHECKING:
-    from collections.abc import Sequence
+    from collections.abc import Iterable
 
     from poetry.core.packages.dependency import Dependency
     from poetry.core.packages.package import Package
@@ -17,13 +17,10 @@ class PackageCollection(List[DependencyPackage]):
     def __init__(
         self,
         dependency: Dependency,
-        packages: Sequence[Package | DependencyPackage] | None = None,
+        packages: Iterable[Package | DependencyPackage] = (),
     ) -> None:
         self._dependency = dependency
 
-        if packages is None:
-            packages = []
-
         super().__init__()
 
         for package in packages:

src/poetry/repositories/repository.py

@@ -5,9 +5,7 @@ import logging
 from typing import TYPE_CHECKING
 
 from packaging.utils import canonicalize_name
-from poetry.core.semver.helpers import parse_constraint
 from poetry.core.semver.version import Version
-from poetry.core.semver.version_constraint import VersionConstraint
 from poetry.core.semver.version_range import VersionRange
 
 from poetry.repositories.exceptions import PackageNotFound
@@ -18,6 +16,7 @@ if TYPE_CHECKING:
     from poetry.core.packages.dependency import Dependency
     from poetry.core.packages.package import Package
     from poetry.core.packages.utils.link import Link
+    from poetry.core.semver.version_constraint import VersionConstraint
 
 
 class Repository:
@@ -103,11 +102,6 @@ class Repository:
         dependency: Dependency,
     ) -> tuple[VersionConstraint, bool]:
         constraint = dependency.constraint
-        if constraint is None:
-            constraint = "*"
-
-        if not isinstance(constraint, VersionConstraint):
-            constraint = parse_constraint(constraint)
 
         allow_prereleases = dependency.allows_prereleases()
         if isinstance(constraint, VersionRange) and (

src/poetry/utils/extras.py

@@ -4,9 +4,9 @@ from typing import TYPE_CHECKING
 
 
 if TYPE_CHECKING:
+    from collections.abc import Collection
     from collections.abc import Iterable
     from collections.abc import Iterator
-    from collections.abc import Sequence
     from typing import Mapping
 
     from packaging.utils import NormalizedName
@@ -14,10 +14,10 @@ if TYPE_CHECKING:
 
 
 def get_extra_package_names(
-    packages: Sequence[Package],
+    packages: Iterable[Package],
     extras: Mapping[str, list[str]],
-    extra_names: Sequence[str],
-) -> Iterable[str]:
+    extra_names: Collection[str],
+) -> Iterable[NormalizedName]:
     """
     Returns all package names required by the given extras.
 

tests/installation/test_pip_installer.py

@@ -296,5 +296,5 @@ def test_install_directory_fallback_on_poetry_create_error(
     assert mock_sdist_builder.call_count == 0
     assert mock_editable_builder.call_count == 0
     assert mock_pip_install.call_count == 1
-    assert mock_pip_install.call_args[1].get("deps") is False
+    assert mock_pip_install.call_args[1].get("deps") is None
     assert mock_pip_install.call_args[1].get("upgrade") is True