A missing enum case in a switch is a warning, not a compile-time error.

pkg/analyzer/test/generated/compile_time_error_code_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 analyzer.test.generated.compile_time_error_code_test;
 
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/parser.dart' show ParserErrorCode;
 import 'package:analyzer/src/generated/source_io.dart';
 
@@ skipping 3529 matching lines @@
 class A {
   get x => 0;
   x(y) {}
 }''');
     computeLibrarySourceErrors(source);
     assertErrors(
         source, [CompileTimeErrorCode.METHOD_AND_GETTER_WITH_SAME_NAME]);
     verify([source]);
   }
 
-  void test_missingEnumConstantInSwitch() {
-    Source source = addSource(r'''
-enum E { ONE, TWO, THREE, FOUR }
-bool odd(E e) {
-  switch (e) {
-    case E.ONE:
-    case E.THREE: return true;
-  }
-  return false;
-}''');
-    computeLibrarySourceErrors(source);
-    assertErrors(source, [
-      CompileTimeErrorCode.MISSING_ENUM_CONSTANT_IN_SWITCH,
-      CompileTimeErrorCode.MISSING_ENUM_CONSTANT_IN_SWITCH
-    ]);
-    verify([source]);
-  }
-
   void test_mixinDeclaresConstructor_classDeclaration() {
     Source source = addSource(r'''
 class A {
   A() {}
 }
 class B extends Object with A {}''');
     computeLibrarySourceErrors(source);
     assertErrors(source, [CompileTimeErrorCode.MIXIN_DECLARES_CONSTRUCTOR]);
     verify([source]);
   }
@@ skipping 2707 matching lines @@
         source, [CompileTimeErrorCode.WRONG_NUMBER_OF_PARAMETERS_FOR_OPERATOR]);
     verify([source]);
     reset();
   }
 
   void _check_wrongNumberOfParametersForOperator1(String name) {
     _check_wrongNumberOfParametersForOperator(name, "");
     _check_wrongNumberOfParametersForOperator(name, "a, b");
   }
 }