Enhance readme handling

src/poetry/core/factory.py

@@ -224,10 +224,10 @@ def _configure_package_metadata(
                 package.readme_content = root / readme["text"]
                 package.readme_content_type = readme["content-type"]
         elif custom_readme := tool_poetry.get("readme"):
-            if isinstance(custom_readme, str):
-                package.readmes = (root / custom_readme,)
-            else:
-                package.readmes = tuple(root / readme for readme in custom_readme)
+            custom_readmes = (
+                (custom_readme,) if isinstance(custom_readme, str) else custom_readme
+            )
+            package.readmes = tuple(root / r for r in custom_readmes if r)
 
     @classmethod
     def _configure_entry_points(

src/poetry/core/masonry/metadata.py

@@ -59,8 +59,20 @@ def from_package(cls, package: ProjectPackage) -> Metadata:
         elif package.readmes:
             descriptions = []
             for readme in package.readmes:
-                with readme.open(encoding="utf-8") as f:
-                    descriptions.append(f.read())
+                try:
+                    descriptions.append(readme.read_text(encoding="utf-8"))
+                except FileNotFoundError as e:
+                    raise FileNotFoundError(
+                        f"Readme path `{readme}` does not exist."
+                    ) from e
+                except IsADirectoryError as e:
+                    raise IsADirectoryError(
+                        f"Readme path `{readme}` is a directory."
+                    ) from e
+                except PermissionError as e:
+                    raise PermissionError(
+                        f"Readme path `{readme}` is not readable."
+                    ) from e
             meta.description = "\n".join(descriptions)
 
         meta.keywords = ",".join(package.keywords)

tests/masonry/test_metadata.py

@@ -0,0 +1,62 @@
+from __future__ import annotations
+
+from pathlib import Path
+from typing import TYPE_CHECKING
+
+import pytest
+
+from poetry.core.masonry.metadata import Metadata
+from poetry.core.packages.project_package import ProjectPackage
+
+
+if TYPE_CHECKING:
+    from pytest_mock import MockerFixture
+
+
+def test_from_package_readme(tmp_path: Path) -> None:
+    readme_path = tmp_path / "README.md"
+    readme_path.write_text("This is a description\néöß", encoding="utf-8")
+
+    package = ProjectPackage("foo", "1.0")
+    package.readmes = (readme_path,)
+
+    metadata = Metadata.from_package(package)
+
+    assert metadata.description == "This is a description\néöß"
+
+
+def test_from_package_multiple_readmes(tmp_path: Path) -> None:
+    readme_path1 = tmp_path / "README1.md"
+    readme_path1.write_text("Description 1", encoding="utf-8")
+
+    readme_path2 = tmp_path / "README2.md"
+    readme_path2.write_text("Description 2", encoding="utf-8")
+
+    package = ProjectPackage("foo", "1.0")
+    package.readmes = (readme_path1, readme_path2)
+
+    metadata = Metadata.from_package(package)
+
+    assert metadata.description == "Description 1\nDescription 2"
+
+
+@pytest.mark.parametrize(
+    ("exception", "message"),
+    [
+        (FileNotFoundError, "Readme path `MyReadme.md` does not exist."),
+        (IsADirectoryError, "Readme path `MyReadme.md` is a directory."),
+        (PermissionError, "Readme path `MyReadme.md` is not readable."),
+    ],
+)
+def test_from_package_readme_issues(
+    mocker: MockerFixture, exception: type[OSError], message: str
+) -> None:
+    package = ProjectPackage("foo", "1.0")
+    package.readmes = (Path("MyReadme.md"),)
+
+    mocker.patch("pathlib.Path.read_text", side_effect=exception)
+
+    with pytest.raises(exception) as e:
+        Metadata.from_package(package)
+
+    assert str(e.value) == message

tests/test_factory.py

@@ -510,6 +510,29 @@ def test_create_poetry_classifiers(
     assert poetry.package.all_classifiers == expected
 
 
+def test_create_poetry_no_readme(tmp_path: Path) -> None:
+    pyproject = tmp_path / "pyproject.toml"
+    pyproject.write_text(
+        '[tool.poetry]\nname="foo"\nversion="1"\nauthors = []\ndescription = ""\n',
+        encoding="utf-8",
+    )
+    poetry = Factory().create_poetry(tmp_path)
+
+    assert not poetry.package.readmes
+
+
+def test_create_poetry_empty_readme(tmp_path: Path) -> None:
+    pyproject = tmp_path / "pyproject.toml"
+    pyproject.write_text(
+        '[tool.poetry]\nname="foo"\nversion="1"\nauthors = []\ndescription = ""\n'
+        'readme = ""\n',
+        encoding="utf-8",
+    )
+    poetry = Factory().create_poetry(tmp_path)
+
+    assert not poetry.package.readmes
+
+
 def test_validate() -> None:
     complete = fixtures_dir / "complete.toml"
     with complete.open("rb") as f: