Removed dependency on typing_extensions & hid uses behind if TYPE_CHECKING guards

Author: dylan-robins

poetry.lock

@@ -24,7 +24,6 @@ include = [
 
 [tool.poetry.dependencies]
 python = "^3.8"
-typing-extensions = "^4.10.0"
 
 [tool.poetry.group.dev.dependencies]
 pre-commit = ">=2.15.0"

pyproject.toml

@@ -8,21 +8,22 @@
 from typing import Any
 from typing import List
 from typing import Union
-from typing import cast
 
 from packaging.utils import canonicalize_name
 
-from poetry.core.packages.project_package import BuildConfigSpec
-from poetry.core.packages.project_package import IncludeSpec
 from poetry.core.utils.helpers import combine_unicode
 from poetry.core.utils.helpers import readme_content_type
 
 
 if TYPE_CHECKING:
+    from typing import cast
+
     from packaging.utils import NormalizedName
 
     from poetry.core.packages.dependency import Dependency
     from poetry.core.packages.dependency_group import DependencyGroup
+    from poetry.core.packages.project_package import BuildConfigSpec
+    from poetry.core.packages.project_package import IncludeSpec
     from poetry.core.packages.project_package import ProjectPackage
     from poetry.core.poetry import Poetry
     from poetry.core.spdx.license import License
@@ -200,9 +201,13 @@ def configure_package(
 
         if "build" in config:
             build = config["build"]
+            if not build:
+                build = {}
             if not isinstance(build, dict):
                 build = {"script": build}
-            package.build_config = cast(BuildConfigSpec, build) or {}
+            if TYPE_CHECKING:
+                cast(BuildConfigSpec, build)
+            package.build_config = build
 
         if "include" in config:
             package.include = []
@@ -215,8 +220,9 @@ def configure_package(
                 if formats and not isinstance(formats, list):
                     formats = [formats]
                 include["format"] = formats
-
-                package.include.append(cast(IncludeSpec, include))
+                if TYPE_CHECKING:
+                    include = cast(IncludeSpec, include)
+                package.include.append(include)
 
         if "exclude" in config:
             package.exclude = config["exclude"]

src/poetry/core/factory.py

@@ -8,38 +8,33 @@
 from typing import Sequence
 from typing import TypedDict
 
-from typing_extensions import NotRequired
-
 from poetry.core.constraints.version import parse_constraint
+from poetry.core.packages.package import Package
+from poetry.core.packages.utils.utils import create_nested_marker
 from poetry.core.version.markers import parse_marker
 
 
 if TYPE_CHECKING:
+    from typing_extensions import NotRequired
+
     from poetry.core.constraints.version import Version
     from poetry.core.packages.dependency import Dependency
 
-from poetry.core.packages.package import Package
-from poetry.core.packages.utils.utils import create_nested_marker
-
-
-SupportedPackageFormats = Literal["sdist", "wheel"]
-
-
-BuildConfigSpec = TypedDict(
-    "BuildConfigSpec",
-    {"script": NotRequired[str], "generate-setup-file": NotRequired[bool]},
-)
-
+    SupportedPackageFormats = Literal["sdist", "wheel"]
 
-class PackageSpec(TypedDict):
-    include: str
-    to: str
-    format: list[SupportedPackageFormats]
+    BuildConfigSpec = TypedDict(
+        "BuildConfigSpec",
+        {"script": NotRequired[str], "generate-setup-file": NotRequired[bool]},
+    )
 
+    class PackageSpec(TypedDict):
+        include: str
+        to: str
+        format: list[SupportedPackageFormats]
 
-class IncludeSpec(TypedDict):
-    path: str
-    format: list[SupportedPackageFormats]
+    class IncludeSpec(TypedDict):
+        path: str
+        format: list[SupportedPackageFormats]
 
 
 class ProjectPackage(Package):