Preserve original names in external from-imports

Author: ryanchou1994

CHANGELOG.md

@@ -1,5 +1,6 @@
 # **Upcoming release**
 
+- #831 Preserve external imported names when renaming their local bindings
 - #850 Update and pin black version in pre-commit and Github Actions
 - #851 Bump supported python version to up to Python 3.14
 - #852 Implement patchedast handlers for TypeAlias

rope/refactor/rename.py

@@ -2,6 +2,7 @@
 from keyword import iskeyword
 
 from rope.base import (
+    ast,
     codeanalyze,
     evaluate,
     exceptions,
@@ -120,7 +121,12 @@ def unsure_func(value=unsure):
         job_set = task_handle.create_jobset("Collecting Changes", len(resources))
         for file_ in resources:
             job_set.started_job(file_.path)
-            new_content = rename_in_module(finder, new_name, resource=file_)
+            new_content = rename_in_module(
+                finder,
+                new_name,
+                resource=file_,
+                preserve_imports=self._get_preserved_imports(file_),
+            )
             if new_content is not None:
                 changes.add_change(ChangeContents(file_, new_content))
             job_set.finished_job()
@@ -130,6 +136,33 @@ def unsure_func(value=unsure):
                 self._rename_module(resource, new_name, changes)
         return changes
 
+    def _get_preserved_imports(self, resource):
+        """Find imported names whose definitions are outside the project."""
+        pymodule = self.project.get_pymodule(resource)
+        lines = codeanalyze.ASTLinesAdapter(pymodule.source_code)
+        for node in ast.walk(pymodule.get_ast()):
+            if not isinstance(node, ast.ImportFrom):
+                continue
+            names = [alias for alias in node.names if alias.name == self.old_name]
+            if not names:
+                continue
+            imported_module = pynames.ImportedModule(
+                pymodule, node.module or "", level=node.level
+            ).get_object()
+            imported_resource = (
+                imported_module.get_resource()
+                if isinstance(imported_module, pyobjects.AbstractModule)
+                else None
+            )
+            if imported_resource is not None and (
+                imported_resource.project == self.project
+                and not self.project.is_ignored(imported_resource)
+            ):
+                continue
+            for alias in names:
+                start, _ = lines[alias]
+                yield start, alias.asname is None
+
     def validate_changes(
         self,
         new_name: str,
@@ -233,13 +266,15 @@ def rename_in_module(
     region=None,
     reads=True,
     writes=True,
+    preserve_imports=None,
 ):
     """Returns the changed source or `None` if there is no changes"""
     if resource is not None:
         source_code = resource.read()
     else:
         source_code = pymodule.source_code
     change_collector = codeanalyze.ChangeCollector(source_code)
+    preserved_imports = None
     for occurrence in occurrences_finder.find_occurrences(resource, pymodule):
         if replace_primary and occurrence.is_a_fixed_primary():
             continue
@@ -252,7 +287,16 @@ def rename_in_module(
         ):
             continue
         if region is None or region[0] <= start < region[1]:
-            change_collector.add_change(start, end, new_name)
+            replacement = new_name
+            if preserve_imports is not None and occurrence.is_in_import_statement():
+                if preserved_imports is None:
+                    preserved_imports = dict(preserve_imports)
+                if start in preserved_imports:
+                    if not preserved_imports[start]:
+                        continue
+                    if source_code[start:end] != new_name:
+                        replacement = source_code[start:end] + " as " + new_name
+            change_collector.add_change(start, end, replacement)
     return change_collector.get_changed()
 
 

ropetest/refactor/renametest.py

@@ -582,6 +582,111 @@ def new_func():
             mod2.read(),
         )
 
+    def test_renaming_external_import_preserves_imported_name(self):
+        self.project.prefs.add("extension_modules", "builtins")
+        code = "from builtins import zip\nresult = list(zip([1], [2]))\n"
+        refactored = self._local_rename(code, code.rindex("zip"), "pairs")
+        self.assertEqual(
+            "from builtins import zip as pairs\nresult = list(pairs([1], [2]))\n",
+            refactored,
+        )
+        namespace = {}
+        exec(refactored, namespace)
+        self.assertEqual([(1, 2)], namespace["result"])
+
+    def test_renaming_external_import_with_same_alias(self):
+        code = "from builtins import zip as zip\nresult = zip([], [])\n"
+        refactored = self._local_rename(code, code.rindex("zip"), "pairs")
+        self.assertEqual(
+            "from builtins import zip as pairs\nresult = pairs([], [])\n",
+            refactored,
+        )
+
+    def test_renaming_external_import_with_different_alias(self):
+        code = "from builtins import zip as pairs\nresult = pairs([], [])\n"
+        refactored = self._local_rename(code, code.rindex("pairs"), "new_pairs")
+        self.assertEqual(
+            "from builtins import zip as new_pairs\nresult = new_pairs([], [])\n",
+            refactored,
+        )
+
+    def test_renaming_multiline_external_import_after_unicode(self):
+        code = dedent("""\
+            café = 1; from builtins import (
+                zip as  # Keep the imported name.
+                zip,
+            )
+            result = zip([], [])
+        """)
+        refactored = self._local_rename(code, code.rindex("zip"), "pairs")
+        self.assertEqual(
+            dedent("""\
+                café = 1; from builtins import (
+                    zip as  # Keep the imported name.
+                    pairs,
+                )
+                result = pairs([], [])
+            """),
+            refactored,
+        )
+
+    def test_renaming_conditional_external_import_from_another_module(self):
+        compat = testutils.create_module(self.project, "compat")
+        compat.write(dedent("""\
+            import sys
+            if sys.version_info[0] >= 3:
+                from builtins import map, zip
+            else:
+                zip = lambda *args: None
+        """))
+        mod = testutils.create_module(self.project, "mod")
+        mod.write("from compat import zip\nresult = list(zip([1], [2]))\n")
+        self._rename(mod, mod.read().rindex("zip"), "pairs")
+        self.assertEqual(
+            dedent("""\
+                import sys
+                if sys.version_info[0] >= 3:
+                    from builtins import map, zip as pairs
+                else:
+                    pairs = lambda *args: None
+            """),
+            compat.read(),
+        )
+        self.assertEqual(
+            "from compat import pairs\nresult = list(pairs([1], [2]))\n",
+            mod.read(),
+        )
+
+    def test_renaming_import_from_external_python_module(self):
+        external_project = testutils.sample_project()
+        self.addCleanup(testutils.remove_project, external_project)
+        external = testutils.create_module(external_project, "external")
+        external.write("value = 42\n")
+        self.project.prefs.add("python_path", external_project.address)
+        code = "from external import value\nresult = value\n"
+        refactored = self._local_rename(code, code.rindex("value"), "new_value")
+        self.assertEqual(
+            "from external import value as new_value\nresult = new_value\n",
+            refactored,
+        )
+        self.assertEqual("value = 42\n", external.read())
+
+    def test_renaming_external_import_does_not_resolve_unrelated_import(self):
+        invalid = testutils.create_module(self.project, "invalid")
+        invalid.write("def broken(:\n")
+        code = (
+            "from invalid import other\n"
+            "from builtins import zip\n"
+            "result = zip([], [])\n"
+        )
+        refactored = self._local_rename(code, code.rindex("zip"), "pairs")
+        self.assertEqual(
+            "from invalid import other\n"
+            "from builtins import zip as pairs\n"
+            "result = pairs([], [])\n",
+            refactored,
+        )
+
     def test_applying_all_changes_together(self):
         mod1 = testutils.create_module(self.project, "mod1")
         mod1.write(dedent("""\