fix issue in const error handling

lib/src/ast.dart

@@ -324,7 +324,7 @@ class HasConstErrorListener extends AnalysisErrorListener {
 
   @override
   void onError(AnalysisError error) {
-    hasConstError = errorCodes.contains(error.errorCode);
+    hasConstError = hasConstError || errorCodes.contains(error.errorCode);
   }
 
   static const List<CompileTimeErrorCode> errorCodes = const [
@@ -340,6 +340,7 @@ class HasConstErrorListener extends AnalysisErrorListener {
     CompileTimeErrorCode.INVALID_CONSTANT,
     CompileTimeErrorCode.MISSING_CONST_IN_LIST_LITERAL,
     CompileTimeErrorCode.MISSING_CONST_IN_MAP_LITERAL,
+    CompileTimeErrorCode.NON_CONSTANT_CASE_EXPRESSION,
     CompileTimeErrorCode.NON_CONSTANT_LIST_ELEMENT,
     CompileTimeErrorCode.NON_CONSTANT_MAP_KEY,
     CompileTimeErrorCode.NON_CONSTANT_MAP_VALUE,

test/all.dart

@@ -4,6 +4,7 @@
 
 import 'package:analyzer/src/lint/io.dart';
 
+import 'ast_test.dart' as ast_test;
 import 'engine_test.dart' as engine_test;
 import 'formatter_test.dart' as formatter_test;
 import 'integration_test.dart' as integration_test;
@@ -17,6 +18,7 @@ main() {
   // Redirect output.
   outSink = new MockIOSink();
 
+  ast_test.main();
   engine_test.main();
   formatter_test.main();
   integration_test.main();

test/ast_test.dart

@@ -0,0 +1,27 @@
+import 'package:analyzer/analyzer.dart';
+import 'package:linter/src/ast.dart';
+import 'package:test/test.dart';
+
+main() {
+  group('HasConstErrorListener', () {
+    test('has hasConstError false by default', () {
+      final listener = new HasConstErrorListener();
+      expect(listener.hasConstError, isFalse);
+    });
+    test('has hasConstError true with a tracked const error', () {
+      final listener = new HasConstErrorListener();
+      listener.onError(new AnalysisError(
+          null, null, null, CompileTimeErrorCode.CONST_WITH_NON_CONST));
+      expect(listener.hasConstError, isTrue);
+    });
+    test('has hasConstError true even if last error is not related to const',
+        () {
+      final listener = new HasConstErrorListener();
+      listener.onError(new AnalysisError(
+          null, null, null, CompileTimeErrorCode.CONST_WITH_NON_CONST));
+      listener.onError(new AnalysisError(
+          null, null, null, CompileTimeErrorCode.ACCESS_PRIVATE_ENUM_FIELD));
+      expect(listener.hasConstError, isTrue);
+    });
+  });
+}