Report separate UNUSED_CATCH_CLAUSE and UNUSED_CATCH_STACK hints.

pkg/analyzer/test/generated/resolver_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library engine.resolver_test;
 
 import 'dart:collection';
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
@@ skipping 4137 matching lines @@
     assertErrors(source, [HintCode.UNUSED_IMPORT]);
     assertNoErrors(source2);
     verify([source, source2]);
   }
 
   void test_unusedLocalVariable_inCatch_exception() {
     enableUnusedLocalVariable = true;
     Source source = addSource(r'''
 main() {
   try {
+  } on String catch (exception) {
+  }
+}''');
+    resolve(source);
+    assertErrors(source, [HintCode.UNUSED_CATCH_CLAUSE]);
+    verify([source]);
+  }
+
+  void test_unusedLocalVariable_inCatch_exception_hasStack() {
+    enableUnusedLocalVariable = true;
+    Source source = addSource(r'''
+main() {
+  try {
+  } catch (exception, stack) {
+    print(stack);
+  }
+}''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
+  void test_unusedLocalVariable_inCatch_exception_noOnClause() {
+    enableUnusedLocalVariable = true;
+    Source source = addSource(r'''
+main() {
+  try {
   } catch (exception) {
   }
 }''');
     resolve(source);
-    assertErrors(source);
+    assertNoErrors(source);
     verify([source]);
   }
 
   void test_unusedLocalVariable_inCatch_stackTrace() {
     enableUnusedLocalVariable = true;
     Source source = addSource(r'''
 main() {
   try {
   } catch (exception, stackTrace) {
   }
 }''');
     resolve(source);
-    assertErrors(source, [HintCode.UNUSED_LOCAL_VARIABLE]);
+    assertErrors(source, [HintCode.UNUSED_CATCH_STACK]);
     verify([source]);
   }
 
   void test_unusedLocalVariable_inCatch_stackTrace_used() {
     enableUnusedLocalVariable = true;
     Source source = addSource(r'''
 main() {
   try {
   } catch (exception, stackTrace) {
     print('exception at $stackTrace');
@@ skipping 3428 matching lines @@
       [List<ErrorCode> expectedErrorCodes = ErrorCode.EMPTY_LIST]) {
     GatheringErrorListener errorListener = new GatheringErrorListener();
     for (AnalysisError error in analysisContext2.computeErrors(source)) {
       ErrorCode errorCode = error.errorCode;
       if (!enableUnusedElement &&
           (errorCode == HintCode.UNUSED_ELEMENT ||
               errorCode == HintCode.UNUSED_FIELD)) {
         continue;
       }
       if (!enableUnusedLocalVariable &&
-          errorCode == HintCode.UNUSED_LOCAL_VARIABLE) {
+          (errorCode == HintCode.UNUSED_CATCH_CLAUSE ||
+              errorCode == HintCode.UNUSED_CATCH_STACK ||
+              errorCode == HintCode.UNUSED_LOCAL_VARIABLE)) {
         continue;
       }
       errorListener.onError(error);
     }
     errorListener.assertErrorsWithCodes(expectedErrorCodes);
   }
 
   /**
    * Assert that no errors have been reported against the given source.
    *
@@ skipping 6024 matching lines @@
         // check propagated type
         FunctionType propagatedType = node.propagatedType as FunctionType;
         expect(propagatedType.returnType, test.typeProvider.stringType);
       } on AnalysisException catch (e, stackTrace) {
         thrownException[0] = new CaughtException(e, stackTrace);
       }
     }
     return null;
   }
 }