Issue 22988. Improve checking for conflicts between parameters and local elements during extracting…

pkg/analysis_server/test/services/refactoring/extract_method_test.dart

Index: pkg/analysis_server/test/services/refactoring/extract_method_test.dart
diff --git a/pkg/analysis_server/test/services/refactoring/extract_method_test.dart b/pkg/analysis_server/test/services/refactoring/extract_method_test.dart
index bec57bd0ada21e4e92346f8ed7261eb9ba881b41..113e3742850bf9f50a872a7eb99492e2b0e316a1 100644
--- a/pkg/analysis_server/test/services/refactoring/extract_method_test.dart
+++ b/pkg/analysis_server/test/services/refactoring/extract_method_test.dart
@@ -384,7 +384,31 @@ main() {
     return _assertFinalConditionsError("Parameter 'dup' already exists");
   }
 
-  test_bad_parameterName_inUse() async {
+  test_bad_parameterName_inUse_function() async {
+    indexTestUnit('''
+main() {
+  int v1 = 1;
+  int v2 = 2;
+// start
+  f(v1, v2);
+// end
+}
+f(a, b) {}
+''');
+    _createRefactoringForStartEndComments();
+    // update parameters
+    await refactoring.checkInitialConditions();
+    {
+      List<RefactoringMethodParameter> parameters = _getParametersCopy();
+      expect(parameters, hasLength(2));
+      parameters[0].name = 'f';
+      refactoring.parameters = parameters;
+    }
+    return _assertFinalConditionsError(
+        "'f' is already used as a name in the selected code");
+  }
+
+  test_bad_parameterName_inUse_localVariable() async {
     indexTestUnit('''
 main() {
   int v1 = 1;
@@ -407,6 +431,32 @@ main() {
         "'a' is already used as a name in the selected code");
   }
 
+  test_bad_parameterName_inUse_method() async {
+    indexTestUnit('''
+class A {
+  main() {
+    int v1 = 1;
+    int v2 = 2;
+  // start
+    m(v1, v2);
+  // end
+  }
+  m(a, b) {}
+}
+''');
+    _createRefactoringForStartEndComments();
+    // update parameters
+    await refactoring.checkInitialConditions();
+    {
+      List<RefactoringMethodParameter> parameters = _getParametersCopy();
+      expect(parameters, hasLength(2));
+      parameters[0].name = 'm';
+      refactoring.parameters = parameters;
+    }
+    return _assertFinalConditionsError(
+        "'m' is already used as a name in the selected code");
+  }
+
   test_bad_selectionEndsInSomeNode() {
     indexTestUnit('''
 main() {
@@ -2213,6 +2263,24 @@ void res(Future<int> v) {
 ''');
   }
 
+  test_statements_parameters_noLocalVariableConflict() async {
+    indexTestUnit('''
+int f(int x) {
+  int y = x + 1;
+// start
+  if (y % 2 == 0) {
+    int y = x + 2;
+    return y;
+  } else {
+    return y;
+  }
+// end
+}
+''');
+    _createRefactoringForStartEndComments();
+    await assertRefactoringConditionsOK();
+  }
+
   test_statements_return_last() {
     indexTestUnit('''
 main() {