Fix computation of errors to not run extra tasks

pkg/analyzer/test/src/task/inputs_test.dart

 // Copyright (c) 2015, 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 test.src.task.inputs_test;
 
 import 'package:analyzer/src/task/inputs.dart';
 import 'package:analyzer/src/task/model.dart';
 import 'package:analyzer/task/model.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../generated/test_support.dart';
 import '../../reflective_tests.dart';
 import '../../utils.dart';
 
 main() {
   initializeTestEnvironment();
+  runReflectiveTests(ConstantTaskInputBuilderTest);
+  runReflectiveTests(ConstantTaskInputTest);
   runReflectiveTests(ListTaskInputImplTest);
   runReflectiveTests(ListToListTaskInputTest);
   runReflectiveTests(ListToListTaskInputBuilderTest);
   runReflectiveTests(ListToMapTaskInputBuilderTest);
   runReflectiveTests(ListToMapTaskInputTest);
   runReflectiveTests(ObjectToListTaskInputBuilderTest);
   runReflectiveTests(ObjectToListTaskInputTest);
   runReflectiveTests(SimpleTaskInputTest);
   runReflectiveTests(SimpleTaskInputBuilderTest);
   runReflectiveTests(TopLevelTaskInputBuilderTest);
 }
 
 @reflectiveTest
+class ConstantTaskInputBuilderTest extends EngineTestCase {
+  static final int value = 7;
+  static final ConstantTaskInput<int> input = new ConstantTaskInput<int>(value);
+
+  ConstantTaskInputBuilder builder;
+
+  void setUp() {
+    builder = new ConstantTaskInputBuilder(input);
+  }
+
+  test_create() {
+    expect(builder, isNotNull);
+    expect(builder.input, input);
+  }
+
+  test_currentResult_afterOneMoveNext() {
+    builder.moveNext();
+    expect(builder.currentResult, null);
+  }
+
+  test_currentResult_beforeMoveNext() {
+    expect(builder.currentResult, null);
+  }
+
+  test_currentTarget_afterOneMoveNext() {
+    builder.moveNext();
+    expect(builder.currentTarget, null);
+  }
+
+  test_currentTarget_beforeMoveNext() {
+    expect(builder.currentTarget, null);
+  }
+
+  test_currentValue_afterOneMoveNext() {
+    builder.moveNext();
+    expect(() {
+      builder.currentValue = 'value';
+    }, throwsStateError);
+  }
+
+  test_currentValue_beforeMoveNext() {
+    expect(() {
+      builder.currentValue = 'value';
+    }, throwsStateError);
+  }
+
+  test_currentValueNotAvailable_afterOneMoveNext() {
+    builder.moveNext();
+    expect(() {
+      builder.currentValueNotAvailable();
+    }, throwsStateError);
+  }
+
+  test_currentValueNotAvailable_beforeMoveNext() {
+    expect(() {
+      builder.currentValueNotAvailable();
+    }, throwsStateError);
+  }
+
+  test_inputValue_afterOneMoveNext() {
+    builder.moveNext();
+    expect(builder.inputValue, value);
+  }
+
+  test_inputValue_beforeMoveNext() {
+    expect(builder.inputValue, value);
+  }
+
+  test_moveNext() {
+    expect(builder.moveNext(), false);
+    expect(builder.moveNext(), false);
+  }
+}
+
+@reflectiveTest
+class ConstantTaskInputTest extends EngineTestCase {
+  test_create() {
+    int value = 3;
+    ConstantTaskInput<int> input = new ConstantTaskInput<int>(value);
+    expect(input, isNotNull);
+    expect(input.value, value);
+  }
+
+  test_createBuilder() {
+    ConstantTaskInput<int> input = new ConstantTaskInput<int>(5);
+    expect(input.createBuilder(), new isInstanceOf<ConstantTaskInputBuilder>());
+  }
+}
+
+@reflectiveTest
 class ListTaskInputImplTest extends EngineTestCase {
   static final AnalysisTarget target = new TestSource();
   static final result1 =
       new ResultDescriptorImpl<List<AnalysisTarget>>('result1', null);
   static final result2 = new ResultDescriptorImpl<int>('result2', null);
 
   test_create() {
     var input = new ListTaskInputImpl<AnalysisTarget>(target, result1);
     expect(input, isNotNull);
     expect(input.target, target);
@@ skipping 752 matching lines @@
   }
 
   test_currentResult_afterOneMoveNext() {
     Map<String, TaskInput> inputDescriptors = {'one': input1, 'two': input2};
     TopLevelTaskInputBuilder builder =
         new TopLevelTaskInputBuilder(inputDescriptors);
     builder.moveNext();
     expect(builder.currentResult, result1);
   }
 
+  test_currentResult_afterTwoMoveNext_withConstantInput() {
+    ConstantTaskInput<int> constantInput = new ConstantTaskInput<int>(11);
+    Map<String, TaskInput> inputDescriptors = {
+      'one': input1,
+      'constant': constantInput,
+      'two': input2
+    };
+    TopLevelTaskInputBuilder builder =
+        new TopLevelTaskInputBuilder(inputDescriptors);
+    builder.moveNext();
+    builder.currentValue = 'value1';
+    builder.moveNext();
+    expect(builder.currentResult, result2);
+  }
+
   test_currentResult_beforeMoveNext() {
     Map<String, TaskInput> inputDescriptors = {};
     TopLevelTaskInputBuilder builder =
         new TopLevelTaskInputBuilder(inputDescriptors);
     expect(builder.currentResult, null);
   }
 
   test_currentTarget_afterComplete() {
     Map<String, TaskInput> inputDescriptors = {'one': input1};
     TopLevelTaskInputBuilder builder =
@@ skipping 15 matching lines @@
   }
 
   test_currentTarget_afterOneMoveNext() {
     Map<String, TaskInput> inputDescriptors = {'one': input1};
     TopLevelTaskInputBuilder builder =
         new TopLevelTaskInputBuilder(inputDescriptors);
     builder.moveNext();
     expect(builder.currentTarget, target);
   }
 
+  test_currentTarget_afterTwoMoveNext_withConstantInput() {
+    ConstantTaskInput<int> constantInput = new ConstantTaskInput<int>(11);
+    Map<String, TaskInput> inputDescriptors = {
+      'one': input1,
+      'constant': constantInput,
+      'two': input2
+    };
+    TopLevelTaskInputBuilder builder =
+        new TopLevelTaskInputBuilder(inputDescriptors);
+    builder.moveNext();
+    builder.currentValue = 'value1';
+    builder.moveNext();
+    expect(builder.currentTarget, target);
+  }
+
   test_currentTarget_beforeMoveNext() {
     Map<String, TaskInput> inputDescriptors = {};
     TopLevelTaskInputBuilder builder =
         new TopLevelTaskInputBuilder(inputDescriptors);
     expect(builder.currentTarget, null);
   }
 
   test_currentValue_afterOneMoveNext() {
     Map<String, TaskInput> inputDescriptors = {'one': input1};
     TopLevelTaskInputBuilder builder =
@@ skipping 94 matching lines @@
   test_moveNext_withSet() {
     Map<String, TaskInput> inputDescriptors = {'one': input1};
     TopLevelTaskInputBuilder builder =
         new TopLevelTaskInputBuilder(inputDescriptors);
     expect(builder.moveNext(), true);
     builder.currentValue = 'value1';
     expect(builder.moveNext(), false);
     expect(builder.moveNext(), false);
   }
 }