Cover parsed source cache parity

tests/main/test_parsed_source_cache_parity.py

@@ -0,0 +1,121 @@
+"""Parity tests for the process-local parsed source cache."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+import pytest
+
+from datamodel_code_generator import InputFileType, _clear_parser_source_data_cache
+from tests.conftest import assert_output
+from tests.main.conftest import JSON_SCHEMA_DATA_PATH, OPEN_API_DATA_PATH, run_main_with_args
+
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+    from pathlib import Path
+
+
+def _input_file_type_option(input_file_type: InputFileType) -> str:
+    match input_file_type:
+        case InputFileType.JsonSchema:
+            return "jsonschema"
+        case InputFileType.OpenAPI:
+            return "openapi"
+        case _:  # pragma: no cover
+            msg = f"Unsupported parsed source cache parity input type: {input_file_type}"
+            raise AssertionError(msg)
+
+
+def _build_generate_args(
+    input_path: Path,
+    output_path: Path,
+    input_file_type: InputFileType,
+    extra_args: Sequence[str] | None,
+) -> list[str]:
+    args = [
+        "--input",
+        str(input_path),
+        "--output",
+        str(output_path),
+        "--input-file-type",
+        _input_file_type_option(input_file_type),
+        "--disable-timestamp",
+        "--formatters",
+        "builtin",
+    ]
+    if extra := list(extra_args or ()):
+        return [*args, *extra]
+    return args
+
+
+def _run_generate_with_parsed_source_cache(
+    input_path: Path,
+    output_path: Path,
+    input_file_type: InputFileType,
+    *,
+    use_cache: bool,
+    extra_args: Sequence[str] | None,
+) -> None:
+    _clear_parser_source_data_cache()
+    run_main_with_args(
+        _build_generate_args(input_path, output_path, input_file_type, extra_args),
+        use_parsed_source_cache=use_cache,
+        use_builtin_default_formatter=False,
+    )
+
+
+@pytest.mark.parametrize(
+    ("input_path", "input_file_type", "extra_args"),
+    [
+        pytest.param(
+            JSON_SCHEMA_DATA_PATH / "external_definitions_root.json",
+            InputFileType.JsonSchema,
+            None,
+            id="jsonschema-external-definitions",
+        ),
+        pytest.param(
+            JSON_SCHEMA_DATA_PATH / "all_of_ref" / "test.json",
+            InputFileType.JsonSchema,
+            ["--class-name", "Test"],
+            id="jsonschema-relative-all-of",
+        ),
+        pytest.param(
+            OPEN_API_DATA_PATH / "paths_external_ref" / "openapi.yaml",
+            InputFileType.OpenAPI,
+            ["--openapi-scopes", "paths"],
+            id="openapi-paths-external-ref",
+        ),
+        pytest.param(
+            OPEN_API_DATA_PATH / "external_ref_mapping" / "api.yaml",
+            InputFileType.OpenAPI,
+            None,
+            id="openapi-external-ref-mapping",
+        ),
+    ],
+)
+def test_generate_output_matches_with_and_without_parsed_source_cache(
+    input_path: Path,
+    input_file_type: InputFileType,
+    extra_args: Sequence[str] | None,
+    tmp_path: Path,
+) -> None:
+    """Keep representative ref-heavy generation output stable across cache states."""
+    cached_output = tmp_path / "cached.py"
+    uncached_output = tmp_path / "uncached.py"
+
+    _run_generate_with_parsed_source_cache(
+        input_path,
+        cached_output,
+        input_file_type,
+        use_cache=True,
+        extra_args=extra_args,
+    )
+    _run_generate_with_parsed_source_cache(
+        input_path,
+        uncached_output,
+        input_file_type,
+        use_cache=False,
+        extra_args=extra_args,
+    )
+
+    assert_output(uncached_output.read_text(encoding="utf-8"), cached_output)