fix: Fix handling of "format" in package includes initialization

Ensure that "format" is always processed as a list when initializing package includes. If not explicit set default to sdist and wheel.

Author: finswimmer

src/poetry/core/masonry/utils/module.py

@@ -72,11 +72,15 @@ def __init__(
             packages = [default_package]
 
         for package in packages:
+            formats = package.get("format", ["sdist", "wheel"])
+            if formats and not isinstance(formats, list):
+                formats = [formats]
+
             self._package_includes.append(
                 PackageInclude(
                     self._path,
                     package["include"],
-                    formats=package["format"],
+                    formats=formats,
                     source=package.get("from"),
                     target=package.get("to"),
                 )

tests/masonry/utils/test_module.py

@@ -0,0 +1,35 @@
+from __future__ import annotations
+
+import pytest
+
+from poetry.core.factory import Factory
+from poetry.core.masonry.utils.module import Module
+from tests.test_factory import fixtures_dir
+
+
+@pytest.mark.parametrize(
+    ["given_format", "expected_formats"],
+    [
+        (None, ["sdist", "wheel"]),
+        ("sdist", ["sdist"]),
+        ("wheel", ["wheel"]),
+        (["sdist", "wheel"], ["sdist", "wheel"]),
+    ],
+)
+def test_create_module_select_correct_formats(
+    given_format: str | list[str] | None, expected_formats: list[str]
+) -> None:
+    directory = fixtures_dir / "project_with_markers_and_extras"
+    poetry = Factory().create_poetry(directory)
+
+    package = poetry.package
+    assert "format" not in package.packages[0]
+
+    if given_format:
+        package.packages[0]["format"] = given_format  # type: ignore[index]
+
+    module = Module(
+        name=package.name, directory=str(directory), packages=package.packages
+    )
+    assert len(module.includes) == 1
+    assert module.includes[0].formats == expected_formats