tests: Add tests for dataclasses extension

Author: pawamoy

tests/test_extensions/test_dataclasses.py

@@ -0,0 +1,170 @@
+"""Test the dataclasses extension."""
+
+from griffe import ParameterKind, load_extensions, temporary_visited_package
+
+
+def test_dataclass_support() -> None:
+    """Test our `dataclass` support."""
+    code = """
+        from dataclasses import dataclass
+
+        @dataclass
+        class Point:
+            x: int
+            '''Docstring for x.'''
+            y: int
+            '''Docstring for y.'''
+    """
+    with temporary_visited_package(
+        "pkg",
+        {"__init__.py": code},
+        extensions=load_extensions("dataclasses"),
+    ) as pkg:
+        point = pkg["Point"]
+    assert "__init__" in point.members
+    init = point["__init__"]
+    assert len(init.parameters) == 3
+    assert "self" in init.parameters
+    assert "x" in init.parameters
+    assert "y" in init.parameters
+    assert str(init.parameters["x"].annotation) == "int"
+    assert str(init.parameters["y"].annotation) == "int"
+    assert init.parameters["x"].docstring.value == "Docstring for x."
+    assert init.parameters["y"].docstring.value == "Docstring for y."
+    assert init.returns == "None"
+
+
+def test_non_init_fields() -> None:
+    """Test that non-init fields are not included in the `__init__` method."""
+    code = """
+        from dataclasses import dataclass, field
+
+        @dataclass
+        class Point:
+            x: int
+            '''Docstring for x.'''
+            y: int = field(init=False)
+            '''Docstring for y.'''
+    """
+    with temporary_visited_package(
+        "pkg",
+        {"__init__.py": code},
+        extensions=load_extensions("dataclasses"),
+    ) as pkg:
+        point = pkg["Point"]
+    assert "__init__" in point.members
+    init = point["__init__"]
+    assert len(init.parameters) == 2
+    assert "self" in init.parameters
+    assert "x" in init.parameters
+    assert "y" not in init.parameters
+
+
+def test_classvar_fields() -> None:
+    """Test that `ClassVar` fields are not included in the `__init__` method."""
+    code = """
+        from dataclasses import dataclass
+        from typing import ClassVar
+
+        @dataclass
+        class Point:
+            x: int
+            '''Docstring for x.'''
+            y: ClassVar[int]
+            '''Docstring for y.'''
+    """
+    with temporary_visited_package(
+        "pkg",
+        {"__init__.py": code},
+        extensions=load_extensions("dataclasses"),
+    ) as pkg:
+        point = pkg["Point"]
+    assert "__init__" in point.members
+    init = point["__init__"]
+    assert len(init.parameters) == 2
+    assert "self" in init.parameters
+    assert "x" in init.parameters
+    assert "y" not in init.parameters
+
+
+def test_kw_only_fields() -> None:
+    """Test that `kw_only` fields are included as keyword-only parameters in the `__init__` method."""
+    code = """
+        from dataclasses import dataclass, field
+
+        @dataclass
+        class Point:
+            x: int
+            '''Docstring for x.'''
+            y: int = field(kw_only=True)
+            '''Docstring for y.'''
+    """
+    with temporary_visited_package(
+        "pkg",
+        {"__init__.py": code},
+        extensions=load_extensions("dataclasses"),
+    ) as pkg:
+        point = pkg["Point"]
+    assert "__init__" in point.members
+    init = point["__init__"]
+    assert len(init.parameters) == 3
+    assert "self" in init.parameters
+    assert "x" in init.parameters
+    assert "y" in init.parameters
+    assert init.parameters["y"].kind is ParameterKind.keyword_only
+
+
+def test_kw_only_sentinel() -> None:
+    """Test that the `KW_ONLY` sentinel works."""
+    code = """
+        from dataclasses import dataclass, KW_ONLY
+
+        @dataclass
+        class Point:
+            x: int
+            '''Docstring for x.'''
+            _: KW_ONLY
+            y: int
+            '''Docstring for y.'''
+    """
+    with temporary_visited_package(
+        "pkg",
+        {"__init__.py": code},
+        extensions=load_extensions("dataclasses"),
+    ) as pkg:
+        point = pkg["Point"]
+    assert "__init__" in point.members
+    init = point["__init__"]
+    assert len(init.parameters) == 3
+    assert "self" in init.parameters
+    assert "x" in init.parameters
+    assert "y" in init.parameters
+    assert init.parameters["y"].kind is ParameterKind.keyword_only
+
+
+def test_all_kw_only_fields() -> None:
+    """Test that all fields can be made keyword-only."""
+    code = """
+        from dataclasses import dataclass
+
+        @dataclass(kw_only=True)
+        class Point:
+            x: int
+            '''Docstring for x.'''
+            y: int
+            '''Docstring for y.'''
+    """
+    with temporary_visited_package(
+        "pkg",
+        {"__init__.py": code},
+        extensions=load_extensions("dataclasses"),
+    ) as pkg:
+        point = pkg["Point"]
+    assert "__init__" in point.members
+    init = point["__init__"]
+    assert len(init.parameters) == 3
+    assert "self" in init.parameters
+    assert "x" in init.parameters
+    assert "y" in init.parameters
+    assert init.parameters["x"].kind is ParameterKind.keyword_only
+    assert init.parameters["y"].kind is ParameterKind.keyword_only