Handle non-mapping in metadata

Author: spoorcc

dfetch/project/metadata.py

@@ -99,6 +99,10 @@ def from_file(cls, path: str) -> "Metadata":
             except (KeyError, TypeError) as exc:
                 raise InvalidMetadataError(str(exc)) from exc
 
+            if not isinstance(data, dict):
+                raise InvalidMetadataError(
+                    f"Expected a mapping under 'dfetch', got {type(data).__name__}"
+                )
             return cls(data)
 
     def fetched(

tests/test_metadata.py

@@ -0,0 +1,102 @@
+"""Test metadata loading."""
+
+# mypy: ignore-errors
+# flake8: noqa
+
+import textwrap
+
+import pytest
+
+from dfetch.project.metadata import InvalidMetadataError, Metadata
+
+VALID_METADATA = """\
+    dfetch:
+      remote_url: https://example.com/repo
+      branch: main
+      tag: ''
+      revision: abc123
+      last_fetch: 01/01/2000, 00:00:00
+      hash: deadbeef
+      patch: ''
+    """
+
+
+def _write_metadata(tmp_path, content):
+    path = tmp_path / ".dfetch_data.yaml"
+    path.write_text(textwrap.dedent(content))
+    return str(path)
+
+
+def test_from_file_raises_when_dfetch_value_is_a_scalar(tmp_path):
+    """A scalar under 'dfetch:' must raise InvalidMetadataError, not AttributeError."""
+    path = _write_metadata(tmp_path, "dfetch: just-a-string\n")
+    with pytest.raises(InvalidMetadataError):
+        Metadata.from_file(path)
+
+
+def test_from_file_raises_when_dfetch_value_is_a_list(tmp_path):
+    """A list under 'dfetch:' must raise InvalidMetadataError, not AttributeError."""
+    path = _write_metadata(tmp_path, "dfetch:\n  - item1\n  - item2\n")
+    with pytest.raises(InvalidMetadataError):
+        Metadata.from_file(path)
+
+
+def test_from_file_raises_when_dfetch_value_is_null(tmp_path):
+    """A null under 'dfetch:' must raise InvalidMetadataError, not AttributeError."""
+    path = _write_metadata(tmp_path, "dfetch:\n")
+    with pytest.raises(InvalidMetadataError):
+        Metadata.from_file(path)
+
+
+def test_from_file_raises_on_invalid_yaml_syntax(tmp_path):
+    """Broken YAML syntax must raise InvalidMetadataError."""
+    path = _write_metadata(tmp_path, "dfetch: [unclosed bracket\n")
+    with pytest.raises(InvalidMetadataError):
+        Metadata.from_file(path)
+
+
+def test_from_file_raises_when_dfetch_key_is_absent(tmp_path):
+    """A file with no 'dfetch' top-level key must raise InvalidMetadataError."""
+    path = _write_metadata(tmp_path, "other_key: value\n")
+    with pytest.raises(InvalidMetadataError):
+        Metadata.from_file(path)
+
+
+def test_from_file_loads_remote_url(tmp_path):
+    """remote_url is read back correctly from a valid file."""
+    path = _write_metadata(tmp_path, VALID_METADATA)
+    meta = Metadata.from_file(path)
+    assert meta.remote_url == "https://example.com/repo"
+
+
+def test_from_file_loads_branch(tmp_path):
+    """branch is read back correctly from a valid file."""
+    path = _write_metadata(tmp_path, VALID_METADATA)
+    meta = Metadata.from_file(path)
+    assert meta.branch == "main"
+
+
+def test_from_file_loads_revision(tmp_path):
+    """revision is read back correctly from a valid file."""
+    path = _write_metadata(tmp_path, VALID_METADATA)
+    meta = Metadata.from_file(path)
+    assert meta.revision == "abc123"
+
+
+def test_from_file_loads_hash(tmp_path):
+    """hash is read back correctly from a valid file."""
+    path = _write_metadata(tmp_path, VALID_METADATA)
+    meta = Metadata.from_file(path)
+    assert meta.hash == "deadbeef"
+
+
+def test_from_file_uses_defaults_for_missing_fields(tmp_path):
+    """A minimal mapping with only the 'dfetch' key and no fields uses defaults."""
+    path = _write_metadata(tmp_path, "dfetch: {}\n")
+    meta = Metadata.from_file(path)
+    assert meta.remote_url == ""
+    assert meta.branch == ""
+    assert meta.revision == ""
+    assert meta.hash == ""
+    assert meta.patch == []
+    assert meta.dependencies == []