Allow non-existant path dependencies

src/poetry/core/packages/directory_dependency.py

@@ -4,6 +4,7 @@
 
 from pathlib import Path
 from typing import Iterable
+from warnings import warn
 
 from poetry.core.packages.dependency import Dependency
 from poetry.core.packages.utils.utils import is_python_project
@@ -12,6 +13,8 @@
 
 
 class DirectoryDependency(Dependency):
+    _full_path: Path | None
+
     def __init__(
         self,
         name: str,
@@ -24,26 +27,10 @@ def __init__(
     ) -> None:
         self._path = path
         self._base = base or Path.cwd()
-        self._full_path = path
-
-        if not self._path.is_absolute():
-            try:
-                self._full_path = self._base.joinpath(self._path).resolve()
-            except FileNotFoundError:
-                raise ValueError(f"Directory {self._path} does not exist")
-
+        self._full_path = None
         self._develop = develop
 
-        if not self._full_path.exists():
-            raise ValueError(f"Directory {self._path} does not exist")
-
-        if self._full_path.is_file():
-            raise ValueError(f"{self._path} is a file, expected a directory")
-
-        if not is_python_project(self._full_path):
-            raise ValueError(
-                f"Directory {self._full_path} does not seem to be a Python package"
-            )
+        full_path = self._get_full_path(False, name)
 
         super().__init__(
             name,
@@ -52,20 +39,55 @@ def __init__(
             optional=optional,
             allows_prereleases=True,
             source_type="directory",
-            source_url=self._full_path.as_posix(),
+            source_url=full_path.as_posix(),
             extras=extras,
         )
-
         # cache this function to avoid multiple IO reads and parsing
         self.supports_poetry = functools.lru_cache(maxsize=1)(self._supports_poetry)
 
+    def _get_full_path(self, raise_if_invalid: bool, name: str) -> Path:
+        if self._full_path is not None:
+            return self._full_path
+        full_path = self._path
+        if not self._path.is_absolute():
+            try:
+                full_path = self._base.joinpath(self._path).resolve()
+            except FileNotFoundError:
+                msg = f"Source directory {self._path} for {name} does not exist"
+                if raise_if_invalid:
+                    raise ValueError(msg)
+                warn(msg, category=UserWarning)
+                return full_path
+
+        if not full_path.exists():
+            msg = f"Source directory {self._path} for {name} does not exist"
+            if raise_if_invalid:
+                raise ValueError(msg)
+            warn(msg, category=UserWarning)
+            return full_path
+
+        if full_path.is_file():
+            raise ValueError(
+                f"Expected source for {name} to be a"
+                f" directory but {self._path} is a file"
+            )
+
+        if not is_python_project(full_path):
+            raise ValueError(
+                f"The source directory {self._full_path} for {name}"
+                " does not seem to be a Python package",
+            )
+
+        self._full_path = full_path
+        return full_path
+
     @property
     def path(self) -> Path:
         return self._path
 
     @property
     def full_path(self) -> Path:
-        return self._full_path
+        return self._get_full_path(True, self.name)
 
     @property
     def base(self) -> Path:
@@ -76,7 +98,7 @@ def develop(self) -> bool:
         return self._develop
 
     def _supports_poetry(self) -> bool:
-        return PyProjectTOML(self._full_path / "pyproject.toml").is_poetry_project()
+        return PyProjectTOML(self.full_path / "pyproject.toml").is_poetry_project()
 
     def is_directory(self) -> bool:
         return True

src/poetry/core/packages/file_dependency.py

@@ -5,12 +5,15 @@
 
 from pathlib import Path
 from typing import Iterable
+from warnings import warn
 
 from poetry.core.packages.dependency import Dependency
 from poetry.core.packages.utils.utils import path_to_url
 
 
 class FileDependency(Dependency):
+    _full_path: Path | None
+
     def __init__(
         self,
         name: str,
@@ -22,19 +25,8 @@ def __init__(
     ) -> None:
         self._path = path
         self._base = base or Path.cwd()
-        self._full_path = path
-
-        if not self._path.is_absolute():
-            try:
-                self._full_path = self._base.joinpath(self._path).resolve()
-            except FileNotFoundError:
-                raise ValueError(f"Directory {self._path} does not exist")
-
-        if not self._full_path.exists():
-            raise ValueError(f"File {self._path} does not exist")
-
-        if self._full_path.is_dir():
-            raise ValueError(f"{self._path} is a directory, expected a file")
+        self._full_path = None
+        full_path = self._get_full_path(False, name)
 
         super().__init__(
             name,
@@ -43,10 +35,40 @@ def __init__(
             optional=optional,
             allows_prereleases=True,
             source_type="file",
-            source_url=self._full_path.as_posix(),
+            source_url=full_path.as_posix(),
             extras=extras,
         )
 
+    def _get_full_path(self, raise_if_invalid: bool, name: str) -> Path:
+        if self._full_path is not None:
+            return self._full_path
+        full_path = self._path
+        if not self._path.is_absolute():
+            try:
+                full_path = self._base.joinpath(self._path).resolve()
+            except FileNotFoundError:
+                msg = f"Source file {self._path} for {name} does not exist"
+                if raise_if_invalid:
+                    raise ValueError(msg)
+                warn(msg, category=UserWarning)
+                return full_path
+
+        if not full_path.exists():
+            msg = f"Source file {self._path} for {name} does not exist"
+            if raise_if_invalid:
+                raise ValueError(msg)
+            warn(msg, category=UserWarning)
+            return full_path
+
+        if full_path.is_dir():
+            raise ValueError(
+                f"Expected source for {name} to be a"
+                f" file but {self._path} is a directory"
+            )
+
+        self._full_path = full_path
+        return full_path
+
     @property
     def base(self) -> Path:
         return self._base
@@ -57,14 +79,14 @@ def path(self) -> Path:
 
     @property
     def full_path(self) -> Path:
-        return self._full_path
+        return self._get_full_path(True, self.name)
 
     def is_file(self) -> bool:
         return True
 
     def hash(self, hash_name: str = "sha256") -> str:
         h = hashlib.new(hash_name)
-        with self._full_path.open("rb") as fp:
+        with self.full_path.open("rb") as fp:
             for content in iter(lambda: fp.read(io.DEFAULT_BUFFER_SIZE), b""):
                 h.update(content)
 

tests/fixtures/non_python_project/pyproject.toml

@@ -0,0 +1 @@
+# missing build section

tests/packages/test_directory_dependency.py

@@ -15,7 +15,7 @@
 
 def test_directory_dependency_must_exist() -> None:
     with pytest.raises(ValueError):
-        DirectoryDependency("demo", DIST_PATH / "invalid")
+        DirectoryDependency("demo", DIST_PATH / "invalid").full_path
 
 
 def _test_directory_dependency_pep_508(

tests/packages/test_file_dependency.py

@@ -22,7 +22,7 @@
 
 def test_file_dependency_wrong_path() -> None:
     with pytest.raises(ValueError):
-        FileDependency("demo", DIST_PATH / "demo-0.2.0.tar.gz")
+        FileDependency("demo", DIST_PATH / "demo-0.2.0.tar.gz").full_path
 
 
 def test_file_dependency_dir() -> None:

tests/test_factory.py

@@ -298,18 +298,6 @@ def test_create_poetry_omits_dev_dependencies_iff_with_dev_is_false() -> None:
     assert any("dev" in r.groups for r in poetry.package.all_requires)
 
 
-def test_create_poetry_fails_with_invalid_dev_dependencies_iff_with_dev_is_true() -> (
-    None
-):
-    with pytest.raises(ValueError) as err:
-        Factory().create_poetry(fixtures_dir / "project_with_invalid_dev_deps")
-    assert "does not exist" in str(err.value)
-
-    Factory().create_poetry(
-        fixtures_dir / "project_with_invalid_dev_deps", with_groups=False
-    )
-
-
 def test_create_poetry_with_groups_and_legacy_dev() -> None:
     poetry = Factory().create_poetry(
         fixtures_dir / "project_with_groups_and_legacy_dev"