init

.venv/lib/python3.8/site-packages/mypy/test/testdiff.py

@@ -0,0 +1,66 @@
+"""Test cases for AST diff (used for fine-grained incremental checking)"""
+
+import os
+from typing import List, Tuple, Dict, Optional
+
+from mypy import build
+from mypy.modulefinder import BuildSource
+from mypy.defaults import PYTHON3_VERSION
+from mypy.errors import CompileError
+from mypy.nodes import MypyFile
+from mypy.options import Options
+from mypy.server.astdiff import snapshot_symbol_table, compare_symbol_table_snapshots
+from mypy.test.config import test_temp_dir
+from mypy.test.data import DataDrivenTestCase, DataSuite
+from mypy.test.helpers import assert_string_arrays_equal, parse_options
+
+
+class ASTDiffSuite(DataSuite):
+    files = [
+        'diff.test',
+    ]
+
+    def run_case(self, testcase: DataDrivenTestCase) -> None:
+        first_src = '\n'.join(testcase.input)
+        files_dict = dict(testcase.files)
+        second_src = files_dict['tmp/next.py']
+        options = parse_options(first_src, testcase, 1)
+
+        messages1, files1 = self.build(first_src, options)
+        messages2, files2 = self.build(second_src, options)
+
+        a = []
+        if messages1:
+            a.extend(messages1)
+        if messages2:
+            a.append('== next ==')
+            a.extend(messages2)
+
+        assert files1 is not None and files2 is not None, ('cases where CompileError'
+                                                           ' occurred should not be run')
+        prefix = '__main__'
+        snapshot1 = snapshot_symbol_table(prefix, files1['__main__'].names)
+        snapshot2 = snapshot_symbol_table(prefix, files2['__main__'].names)
+        diff = compare_symbol_table_snapshots(prefix, snapshot1, snapshot2)
+        for trigger in sorted(diff):
+            a.append(trigger)
+
+        assert_string_arrays_equal(
+            testcase.output, a,
+            'Invalid output ({}, line {})'.format(testcase.file,
+                                                  testcase.line))
+
+    def build(self, source: str,
+              options: Options) -> Tuple[List[str], Optional[Dict[str, MypyFile]]]:
+        options.use_builtins_fixtures = True
+        options.show_traceback = True
+        options.cache_dir = os.devnull
+        options.python_version = PYTHON3_VERSION
+        try:
+            result = build.build(sources=[BuildSource('main', None, source)],
+                                 options=options,
+                                 alt_lib_path=test_temp_dir)
+        except CompileError as e:
+            # TODO: Is it okay to return None?
+            return e.messages, None
+        return result.errors, result.files