fix(move): Moves decorated function or class to other module

fixes python-rope#419 fixes python-rope#439

CHANGELOG.md

@@ -2,6 +2,11 @@
 ## New feature
 - #464 Improve autoimport code to use a sqllite3 database, cache all available modules quickly, search for names and produce import statements, sort import statements.
 
+## Bug fixes
+
+- #419 Fix bug while moving decorated function (@dryobates)
+- #439 Fix bug while moving decorated class (@dryobates)
+
 # Release 1.0.0
 
 Date: 2022-04-08

rope/refactor/importutils/module_imports.py

@@ -278,7 +278,8 @@ def _first_import_line(self):
                 nodes[lineno], ast.ImportFrom
             ):
                 return nodes[lineno].lineno
-            lineno = self.pymodule.logical_lines.logical_line_in(nodes[lineno].lineno)[
+            first_line = get_first_decorator_or_function_start_line(nodes[lineno])
+            lineno = self.pymodule.logical_lines.logical_line_in(first_line)[
                 0
             ]
         else:
@@ -288,6 +289,7 @@ def _first_import_line(self):
             self.pymodule.lines.get_line, lineno - 1, 1, -1
         )
 
+
     def _get_import_name(self, import_stmt):
         import_info = import_stmt.import_info
         if hasattr(import_info, "module_name"):
@@ -340,6 +342,12 @@ def remove_pyname(self, pyname):
             import_stmt.accept(visitor)
 
 
+def get_first_decorator_or_function_start_line(node):
+    decorators = getattr(node, "decorator_list", [])
+    first_line = min([decorator.lineno for decorator in decorators] + [node.lineno])
+    return first_line
+
+
 def _count_blank_lines(get_line, start, end, step=1):
     count = 0
     for idx in range(start, end, step):

rope/refactor/move.py

@@ -16,6 +16,7 @@
 )
 from rope.base.change import ChangeSet, ChangeContents, MoveResource
 from rope.refactor import importutils, rename, occurrences, sourceutils, functionutils
+from rope.refactor.importutils.module_imports import get_first_decorator_or_function_start_line
 
 
 def create_move(project, resource, offset=None):
@@ -435,9 +436,9 @@ def _get_moving_region(self):
             start = lines.get_line_start(lineno)
             end_line = logical_lines.logical_line_in(lineno)[1]
         else:
-            scope = self.old_pyname.get_object().get_scope()
-            start = lines.get_line_start(scope.get_start())
-            end_line = scope.get_end()
+            node = self.old_pyname.get_object().ast_node
+            start = lines.get_line_start(get_first_decorator_or_function_start_line(node))
+            end_line = self.old_pyname.get_object().get_scope().get_end()
 
         # Include comment lines before the definition
         start_line = lines.get_line_number(start)

ropetest/refactor/movetest.py

@@ -1257,3 +1257,50 @@ def f(): pass
         self.project.do(mover.get_changes(self.mod1))
         expected = "%s\n%s" % (code1, code2)
         self.assertEqual(expected, self.mod1.read())
+
+    def test_moving_decorated_function(self):
+        self.mod1.write(
+            dedent("""\
+                def hello(func):
+                    return func
+                @hello
+                def foo():
+                    pass
+            """)
+        )
+        self._move(self.mod1, self.mod1.read().index("foo") + 1, self.mod2)
+        self.assertEqual("def hello(func):\n    return func\n", self.mod1.read())
+        self.assertEqual(
+            dedent("""\
+                from mod1 import hello
+                
+
+                @hello
+                def foo():
+                    pass
+            """),
+            self.mod2.read(),
+        )
+
+    def test_moving_decorated_class(self):
+        self.mod1.write(
+            dedent("""\
+                from dataclasses import dataclass
+                @dataclass
+                class AClass:
+                    pass
+            """)
+        )
+        self._move(self.mod1, self.mod1.read().index("AClass") + 1, self.mod2)
+        self.assertEqual("", self.mod1.read())
+        self.assertEqual(
+            dedent("""\
+                from dataclasses import dataclass
+                
+
+                @dataclass
+                class AClass:
+                    pass
+            """),
+            self.mod2.read(),
+        )