| 5 | """Test mixing to have basic assertions for AST nodes.""" |
| 6 | |
| 7 | def assertASTEqual(self, ast1, ast2): |
| 8 | # Ensure the comparisons start at an AST node |
| 9 | self.assertIsInstance(ast1, ast.AST) |
| 10 | self.assertIsInstance(ast2, ast.AST) |
| 11 | |
| 12 | # An AST comparison routine modeled after ast.dump(), but |
| 13 | # instead of string building, it traverses the two trees |
| 14 | # in lock-step. |
| 15 | def traverse_compare(a, b, missing=object()): |
| 16 | if type(a) is not type(b): |
| 17 | self.fail(f"{type(a)!r} is not {type(b)!r}") |
| 18 | if isinstance(a, ast.AST): |
| 19 | for field in a._fields: |
| 20 | if isinstance(a, ast.Constant) and field == "kind": |
| 21 | # Skip the 'kind' field for ast.Constant |
| 22 | continue |
| 23 | value1 = getattr(a, field, missing) |
| 24 | value2 = getattr(b, field, missing) |
| 25 | # Singletons are equal by definition, so further |
| 26 | # testing can be skipped. |
| 27 | if value1 is not value2: |
| 28 | traverse_compare(value1, value2) |
| 29 | elif isinstance(a, list): |
| 30 | try: |
| 31 | for node1, node2 in zip(a, b, strict=True): |
| 32 | traverse_compare(node1, node2) |
| 33 | except ValueError: |
| 34 | # Attempt a "pretty" error ala assertSequenceEqual() |
| 35 | len1 = len(a) |
| 36 | len2 = len(b) |
| 37 | if len1 > len2: |
| 38 | what = "First" |
| 39 | diff = len1 - len2 |
| 40 | else: |
| 41 | what = "Second" |
| 42 | diff = len2 - len1 |
| 43 | msg = f"{what} list contains {diff} additional elements." |
| 44 | raise self.failureException(msg) from None |
| 45 | elif a != b: |
| 46 | self.fail(f"{a!r} != {b!r}") |
| 47 | traverse_compare(ast1, ast2) |