tests: add testcase that shows that pyreverse will not extract the inheritance link for a flat folder as described in #7686

pylint/testutils/pyreverse.py

@@ -110,6 +110,34 @@ def get_functional_test_files(
     return test_files
 
 
+def get_functional_test_packages(
+    root_directory: Path,
+) -> list[FunctionalPyreverseTestfile]:
+    """Treat every subdirectory as a package and get all functional test files."""
+    test_files = []
+    for package_directory in root_directory.iterdir():
+        package_name = package_directory.name
+        config_file = package_directory / f"{package_name}.rc"
+        if config_file.exists():
+            test_files.append(
+                FunctionalPyreverseTestfile(
+                    source=package_directory, options=_read_config(config_file)
+                )
+            )
+        else:
+            test_files.append(
+                FunctionalPyreverseTestfile(
+                    source=package_directory,
+                    options={
+                        "source_roots": [],
+                        "output_formats": ["mmd"],
+                        "command_line_args": [],
+                    },
+                )
+            )
+    return test_files
+
+
 def _read_config(config_file: Path) -> TestFileOptions:
     config = configparser.ConfigParser()
     config.read(str(config_file))

tests/pyreverse/functional/class_diagrams/inheritance/complex_inheritance.mmd

@@ -0,0 +1,11 @@
+classDiagram
+  class AbstractParent {
+  }
+  class Child {
+  }
+  class ConcreteChild {
+  }
+  class GenericParent {
+  }
+  Child --|> AbstractParent
+  ConcreteChild --|> GenericParent

tests/pyreverse/functional/class_diagrams/inheritance/complex_inheritance.py

@@ -0,0 +1,24 @@
+from abc import ABC
+from dataclasses import dataclass
+from typing import Generic, TypeVar
+
+
+@dataclass
+class AbstractParent(ABC):
+    """parent class"""
+
+
+@dataclass
+class Child(AbstractParent):
+    """child class"""
+
+
+GenericType = TypeVar("GenericType")
+
+
+class GenericParent(Generic[GenericType]):
+    """parent class"""
+
+
+class ConcreteChild(GenericParent[int]):
+    """child class"""

tests/pyreverse/functional/packages/complex_inheritance/child.py

@@ -0,0 +1,9 @@
+from dataclasses import dataclass
+
+from parent import AbstractParent
+
+
+@dataclass
+class Child(AbstractParent):
+    """child class"""
+    pass

tests/pyreverse/functional/packages/complex_inheritance/complex_inheritance.mmd

@@ -0,0 +1,6 @@
+classDiagram
+  class Child {
+  }
+  class AbstractParent {
+  }
+  Child --|> AbstractParent

tests/pyreverse/functional/packages/complex_inheritance/complex_inheritance.rc

@@ -0,0 +1,2 @@
+[testoptions]
+command_line_args=-ASmy

tests/pyreverse/functional/packages/complex_inheritance/parent.py

@@ -0,0 +1,7 @@
+from abc import ABC
+from dataclasses import dataclass
+
+
+@dataclass
+class AbstractParent(ABC):
+    """parent class"""

tests/pyreverse/test_pyreverse_functional.py

@@ -10,12 +10,18 @@
 from pylint.testutils.pyreverse import (
     FunctionalPyreverseTestfile,
     get_functional_test_files,
+    get_functional_test_packages,
 )
 
 FUNCTIONAL_DIR = Path(__file__).parent / "functional"
 CLASS_DIAGRAMS_DIR = FUNCTIONAL_DIR / "class_diagrams"
 CLASS_DIAGRAM_TESTS = get_functional_test_files(CLASS_DIAGRAMS_DIR)
 CLASS_DIAGRAM_TEST_IDS = [testfile.source.stem for testfile in CLASS_DIAGRAM_TESTS]
+PACKAGE_DIAGRAMS_DIR = FUNCTIONAL_DIR / "packages"
+PACKAGE_DIAGRAM_TESTS = get_functional_test_packages(PACKAGE_DIAGRAMS_DIR)
+PACKAGE_DIAGRAM_TEST_IDS = [
+    test_package.source.name for test_package in PACKAGE_DIAGRAM_TESTS
+]
 
 
 @pytest.mark.parametrize(
@@ -49,3 +55,36 @@ def test_class_diagrams(testfile: FunctionalPyreverseTestfile, tmp_path: Path) -
         assert testfile.source.with_suffix(f".{output_format}").read_text(
             encoding="utf8"
         ) == (tmp_path / f"classes.{output_format}").read_text(encoding="utf8")
+
+
+@pytest.mark.parametrize(
+    "test_package",
+    PACKAGE_DIAGRAM_TESTS,
+    ids=PACKAGE_DIAGRAM_TEST_IDS,
+)
+def test_packages(test_package: FunctionalPyreverseTestfile, tmp_path: Path) -> None:
+    input_path = test_package.source
+    if test_package.options["source_roots"]:
+        source_roots = ",".join(
+            [
+                os.path.realpath(
+                    os.path.expanduser(os.path.join(input_path, source_root))
+                )
+                for source_root in test_package.options["source_roots"]
+            ]
+        )
+    else:
+        source_roots = ""
+    for output_format in test_package.options["output_formats"]:
+        output_file = input_path / f"{input_path.name}.{output_format}"
+        with pytest.raises(SystemExit) as sys_exit:
+            args = ["-o", f"{output_format}", "-d", str(tmp_path)]
+            if source_roots:
+                args += ["--source-roots", source_roots]
+            args.extend(test_package.options["command_line_args"])
+            args += [str(input_path)]
+            Run(args)
+        assert sys_exit.value.code == 0
+        assert output_file.read_text(encoding="utf8") == (
+            tmp_path / f"classes.{output_format}"
+        ).read_text(encoding="utf8")