Major fixes and new features

venv/lib/python3.12/site-packages/mypy/test/testtransform.py

@@ -0,0 +1,66 @@
+"""Identity AST transform test cases"""
+
+from __future__ import annotations
+
+from mypy import build
+from mypy.errors import CompileError
+from mypy.modulefinder import BuildSource
+from mypy.options import TYPE_VAR_TUPLE, UNPACK
+from mypy.test.config import test_temp_dir
+from mypy.test.data import DataDrivenTestCase, DataSuite
+from mypy.test.helpers import assert_string_arrays_equal, normalize_error_messages, parse_options
+from mypy.test.visitors import TypeAssertTransformVisitor
+
+
+class TransformSuite(DataSuite):
+    required_out_section = True
+    # Reuse semantic analysis test cases.
+    files = [
+        "semanal-basic.test",
+        "semanal-expressions.test",
+        "semanal-classes.test",
+        "semanal-types.test",
+        "semanal-modules.test",
+        "semanal-statements.test",
+        "semanal-abstractclasses.test",
+    ]
+    native_sep = True
+
+    def run_case(self, testcase: DataDrivenTestCase) -> None:
+        test_transform(testcase)
+
+
+def test_transform(testcase: DataDrivenTestCase) -> None:
+    """Perform an identity transform test case."""
+
+    try:
+        src = "\n".join(testcase.input)
+        options = parse_options(src, testcase, 1)
+        options.use_builtins_fixtures = True
+        options.semantic_analysis_only = True
+        options.enable_incomplete_feature = [TYPE_VAR_TUPLE, UNPACK]
+        options.show_traceback = True
+        options.force_uppercase_builtins = True
+        result = build.build(
+            sources=[BuildSource("main", None, src)], options=options, alt_lib_path=test_temp_dir
+        )
+        a = result.errors
+        if a:
+            raise CompileError(a)
+        # Include string representations of the source files in the actual
+        # output.
+        for module in sorted(result.files.keys()):
+            if module in testcase.test_modules:
+                t = TypeAssertTransformVisitor()
+                t.test_only = True
+                file = t.mypyfile(result.files[module])
+                a += file.str_with_options(options).split("\n")
+    except CompileError as e:
+        a = e.messages
+    if testcase.normalize_output:
+        a = normalize_error_messages(a)
+    assert_string_arrays_equal(
+        testcase.output,
+        a,
+        f"Invalid semantic analyzer output ({testcase.file}, line {testcase.line})",
+    )