Compute IGNORE_INFO and filter DART_ERRORS.

pkg/analyzer/lib/src/task/dart.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 analyzer.src.task.dart;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 2579 matching lines @@
       return errors;
     }
 
     IgnoreInfo ignoreInfo = getRequiredInput(IGNORE_INFO_INPUT);
     if (!ignoreInfo.hasIgnores) {
       return errors;
     }
 
     LineInfo lineInfo = getRequiredInput(LINE_INFO_INPUT);
 
-    bool isIgnored(AnalysisError error) {
-      int errorLine = lineInfo.getLocation(error.offset).lineNumber;
-      String errorCode = error.errorCode.name.toLowerCase();
-      // Ignores can be on the line or just preceding the error.
-      return ignoreInfo.ignoredAt(errorCode, errorLine) ||
-          ignoreInfo.ignoredAt(errorCode, errorLine - 1);
-    }
-
-    return errors.where((AnalysisError e) => !isIgnored(e)).toList();
+    return filterIgnored(errors, ignoreInfo, lineInfo);
   }
 
   /**
    * Return a map from the names of the inputs of this kind of task to the task
    * input descriptors describing those inputs for a task with the
    * given [target].
    */
   static Map<String, TaskInput> buildInputs(AnalysisTarget target) {
     Source source = target;
     Map<String, TaskInput> inputs = <String, TaskInput>{};
@@ skipping 24 matching lines @@
   }
 
   /**
    * Create a [DartErrorsTask] based on the given [target] in the given
    * [context].
    */
   static DartErrorsTask createTask(
       AnalysisContext context, AnalysisTarget target) {
     return new DartErrorsTask(context, target);
   }
+
+  /**
+   * Return a new list with items from [errors] which are not filtered out by
+   * the [ignoreInfo].
+   */
+  static List<AnalysisError> filterIgnored(
+      List<AnalysisError> errors, IgnoreInfo ignoreInfo, LineInfo lineInfo) {
+    if (errors.isEmpty || !ignoreInfo.hasIgnores) {
+      return errors;
+    }
+
+    bool isIgnored(AnalysisError error) {
+      int errorLine = lineInfo.getLocation(error.offset).lineNumber;
+      String errorCode = error.errorCode.name.toLowerCase();
+      // Ignores can be on the line or just preceding the error.
+      return ignoreInfo.ignoredAt(errorCode, errorLine) ||
+          ignoreInfo.ignoredAt(errorCode, errorLine - 1);
+    }
+
+    return errors.where((AnalysisError e) => !isIgnored(e)).toList();
+  }
 }
 
 /**
  * A task that builds [RESOLVED_UNIT13] for a unit.
  */
 class EvaluateUnitConstantsTask extends SourceBasedAnalysisTask {
   /**
    * The name of the [RESOLVED_UNIT12] input.
    */
   static const String UNIT_INPUT = 'UNIT_INPUT';
@@ skipping 3274 matching lines @@
 
   @override
   bool moveNext() {
     if (_newSources.isEmpty) {
       return false;
     }
     currentTarget = _newSources.removeLast();
     return true;
   }
 }