Implement test case for pathnode.

Author: tobiasraabe

src/_pytask/nodes.py

@@ -64,6 +64,7 @@ def __attrs_post_init__(self: Task) -> None:
             self.short_name = self.name
 
     def state(self, hash: bool = False) -> str | None:  # noqa: A002
+        """Return the state of the node."""
         if hash and self.path.exists():
             return hashlib.sha256(self.path.read_bytes()).hexdigest()
         if not hash and self.path.exists():
@@ -102,6 +103,7 @@ def value(self) -> Path:
 
     @value.setter
     def value(self, value: Path) -> None:
+        """Set path and if other attributes are not set, set sensible defaults."""
         if not isinstance(value, Path):
             raise TypeError("'value' must be a 'pathlib.Path'.")
         if not self.name:
@@ -133,6 +135,17 @@ def state(self) -> str | None:
     def load(self) -> Path:
         return self.value
 
+    def save(self, value: bytes | str) -> None:
+        """Save strings or bytes to file."""
+        if isinstance(value, str):
+            self.path.write_text(value)
+        elif isinstance(value, bytes):
+            self.path.write_bytes(value)
+        else:
+            raise TypeError(
+                f"'PathNode' can only save 'str' and 'bytes', not {type(value)}"
+            )
+
 
 @define(kw_only=True)
 class PythonNode(Node):

tests/test_execute.py

@@ -532,7 +532,6 @@ def test_error_with_multiple_different_dep_annotations(runner, tmp_path):
     from pathlib import Path
     from typing_extensions import Annotated
     from pytask import Product, PythonNode, PathNode
-    from typing import Any
 
     def task_example(
         dependency: Annotated[Any, PythonNode(), PathNode()] = "hello",
@@ -547,6 +546,25 @@ def task_example(
     assert "Parameter 'dependency'" in result.output
 
 
+@pytest.mark.end_to_end()
+def test_return_with_pathnode_annotation_as_return(runner, tmp_path):
+    source = """
+    from pathlib import Path
+    from typing import Any
+    from typing_extensions import Annotated
+    from pytask import PathNode
+
+    node = PathNode.from_path(Path(__file__).parent.joinpath("file.txt"))
+
+    def task_example() -> Annotated[str, node]:
+        return "Hello, World!"
+    """
+    tmp_path.joinpath("task_module.py").write_text(textwrap.dedent(source))
+    result = runner.invoke(cli, [tmp_path.as_posix()])
+    assert result.exit_code == ExitCode.OK
+    assert tmp_path.joinpath("file.txt").read_text() == "Hello, World!"
+
+
 @pytest.mark.end_to_end()
 def test_return_with_custom_type_annotation_as_return(runner, tmp_path):
     source = """