`LineInfo` line-end detection fixes.

pkg/analyzer/test/src/task/options_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.options_test;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/source/analysis_options_provider.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
@@ skipping 14 matching lines @@
 }
 
 isInstanceOf isGenerateOptionsErrorsTask =
     new isInstanceOf<GenerateOptionsErrorsTask>();
 
 @reflectiveTest
 class GenerateOptionsErrorsTaskTest extends AbstractContextTest {
   final optionsFilePath = '/${AnalysisEngine.ANALYSIS_OPTIONS_FILE}';
 
   Source source;
+  LineInfo lineInfo(String source) =>
+      GenerateOptionsErrorsTask.computeLineInfo(source);
+
   @override
   setUp() {
     super.setUp();
     source = newSource(optionsFilePath);
   }
 
   test_buildInputs() {
     Map<String, TaskInput> inputs =
         GenerateOptionsErrorsTask.buildInputs(source);
     expect(inputs, isNotNull);
     expect(inputs.keys,
         unorderedEquals([GenerateOptionsErrorsTask.CONTENT_INPUT_NAME]));
   }
 
+  test_compute_lineInfo() {
+    expect(lineInfo('foo\nbar').getLocation(4).lineNumber, 2);
+    expect(lineInfo('foo\nbar').getLocation(4).columnNumber, 1);
+    expect(lineInfo('foo\r\nbar').getLocation(5).lineNumber, 2);
+    expect(lineInfo('foo\r\nbar').getLocation(5).columnNumber, 1);
+    expect(lineInfo('foo\rbar').getLocation(4).lineNumber, 2);
+    expect(lineInfo('foo\rbar').getLocation(4).columnNumber, 1);
+    expect(lineInfo('foo').getLocation(0).lineNumber, 1);
+    expect(lineInfo('foo').getLocation(0).columnNumber, 1);
+    expect(lineInfo('').getLocation(1).lineNumber, 1);
+  }
+
   test_constructor() {
     GenerateOptionsErrorsTask task =
         new GenerateOptionsErrorsTask(context, source);
     expect(task, isNotNull);
     expect(task.context, context);
     expect(task.target, source);
   }
 
   test_createTask() {
     GenerateOptionsErrorsTask task =
@@ skipping 110 matching lines @@
         [AnalysisOptionsWarningCode.UNSUPPORTED_OPTION]);
   }
 
   void validate(String source, List<AnalysisOptionsErrorCode> expected) {
     var options = optionsProvider.getOptionsFromString(source);
     var errors = validator.validate(options);
     expect(errors.map((AnalysisError e) => e.errorCode),
         unorderedEquals(expected));
   }
 }