Disable completion in comment text.

It drives me nuts when I try to type some text and IDEA replaces my words with some random identifies.

R=brianwilkerson@google.com, danrubel@google.com
BUG=

Review URL: https://codereview.chromium.org/1410893002 .

pkg/analysis_server/lib/src/provisional/completion/dart/completion_target.dart

@@ -102,6 +102,12 @@ class CompletionTarget {
    */
   final Object entity;
 
+  /**
+   * The [entity] is a comment token, which is either not a documentation
+   * comment or the position is not in a [CommentReference].
+   */
+  final bool isCommentText;
+
   /**
    * If the target is an argument in an [ArgumentList], then this is the index
    * of the argument in the list, otherwise this is `null`.
@@ -145,8 +151,13 @@ class CompletionTarget {
       for (var entity in containingNode.childEntities) {
         if (entity is Token) {
           if (_isCandidateToken(entity, offset)) {
+            // Try to replace with a comment token.
+            Token commentToken = _getContainingCommentToken(entity, offset);
+            if (commentToken != null) {
+              return new CompletionTarget._(containingNode, commentToken, true);
+            }
             // Target found.
-            return new CompletionTarget._(containingNode, entity);
+            return new CompletionTarget._(containingNode, entity, false);
           } else {
             // Since entity is a token, we don't need to look inside it; just
             // proceed to the next entity.
@@ -162,19 +173,24 @@ class CompletionTarget {
 
           // If the node is a candidate target, then we are done.
           if (_isCandidateNode(entity, offset)) {
-            // Check to see if the offset is in a preceeding comment
-            Token commentToken = _getContainingCommentToken(entity, offset);
+            // Check to see if the offset is in a preceding comment
+            Token commentToken =
+                _getContainingCommentToken(entity.beginToken, offset);
             if (commentToken != null) {
               entity = commentToken;
-              // If the preceeding comment is dartdoc token then update
-              // the containing node to be the dartdoc comment
+              // If the preceding comment is dartdoc token, then update
+              // the containing node to be the dartdoc comment.
+              // Otherwise completion is not required.
               Comment docComment =
                   _getContainingDocComment(containingNode, commentToken);
               if (docComment != null) {
                 containingNode = docComment;
+              } else {
+                return new CompletionTarget._(
+                    compilationUnit, commentToken, true);
               }
             }
-            return new CompletionTarget._(containingNode, entity);
+            return new CompletionTarget._(containingNode, entity, false);
           }
 
           // Otherwise, the completion target is somewhere inside the entity,
@@ -198,7 +214,7 @@ class CompletionTarget {
 
       // Since no completion target was found, we set the completion target
       // entity to null and use the compilationUnit as the parent.
-      return new CompletionTarget._(compilationUnit, null);
+      return new CompletionTarget._(compilationUnit, null, false);
     }
   }
 
@@ -206,7 +222,7 @@ class CompletionTarget {
    * Create a [CompletionTarget] holding the given [containingNode] and
    * [entity].
    */
-  CompletionTarget._(AstNode containingNode, Object entity)
+  CompletionTarget._(AstNode containingNode, Object entity, this.isCommentText)
       : this.containingNode = containingNode,
         this.entity = entity,
         this.argIndex = _computeArgIndex(containingNode, entity);
@@ -252,15 +268,14 @@ class CompletionTarget {
   }
 
   /**
-   * Determine if the offset is contained in a preceeding comment token
+   * Determine if the offset is contained in a preceding comment token
    * and return that token, otherwise return `null`.
    */
-  static Token _getContainingCommentToken(AstNode node, int offset) {
-    if (offset >= node.offset) {
+  static Token _getContainingCommentToken(Token token, int offset) {
+    if (token == null) {
       return null;
     }
-    Token token = node.beginToken;
-    if (token == null) {
+    if (offset >= token.offset) {
       return null;
     }
     token = token.precedingComments;

pkg/analysis_server/lib/src/services/completion/imported_reference_contributor.dart

@@ -30,6 +30,11 @@ class ImportedReferenceContributor extends DartCompletionContributor {
 
   @override
   bool computeFast(DartCompletionRequest request) {
+    // Don't suggest in comments.
+    if (request.target.isCommentText) {
+      return true;
+    }
+
     OpType optype = request.optype;
     if (!optype.isPrefixed) {
       if (optype.includeReturnValueSuggestions ||

pkg/analysis_server/lib/src/services/completion/keyword_contributor.dart

@@ -22,7 +22,9 @@ const AWAIT = 'await';
 class KeywordContributor extends DartCompletionContributor {
   @override
   bool computeFast(DartCompletionRequest request) {
-    request.target.containingNode.accept(new _KeywordVisitor(request));
+    if (!request.target.isCommentText) {
+      request.target.containingNode.accept(new _KeywordVisitor(request));
+    }
     return true;
   }
 
@@ -33,7 +35,7 @@ class KeywordContributor extends DartCompletionContributor {
 }
 
 /**
- * A vistor for generating keyword suggestions.
+ * A visitor for generating keyword suggestions.
  */
 class _KeywordVisitor extends GeneralizingAstVisitor {
   final DartCompletionRequest request;
@@ -176,9 +178,9 @@ class _KeywordVisitor extends GeneralizingAstVisitor {
 
   @override
   visitFormalParameterList(FormalParameterList node) {
-    AstNode constructorDecl =
+    AstNode constructorDeclaration =
         node.getAncestor((p) => p is ConstructorDeclaration);
-    if (constructorDecl != null) {
+    if (constructorDeclaration != null) {
       _addSuggestions([Keyword.THIS]);
     }
   }

pkg/analysis_server/lib/src/services/completion/local_reference_contributor.dart

@@ -24,6 +24,11 @@ import 'package:analyzer/src/generated/utilities_dart.dart';
 class LocalReferenceContributor extends DartCompletionContributor {
   @override
   bool computeFast(DartCompletionRequest request) {
+    // Don't suggest in comments.
+    if (request.target.isCommentText) {
+      return true;
+    }
+
     OpType optype = request.optype;
 
     // Collect suggestions from the specific child [AstNode] that contains

pkg/analysis_server/test/services/completion/imported_reference_contributor_test.dart

@@ -490,6 +490,17 @@ class B extends A {
     });
   }
 
+  test_inComment_endOfLine() {
+    addTestSource('''
+main() {
+  // text ^
+}
+''');
+    return computeFull((bool result) {
+      assertNoSuggestions();
+    });
+  }
+
   test_InstanceCreationExpression() {
     addSource(
         '/testA.dart',

pkg/analysis_server/test/services/completion/keyword_contributor_test.dart

@@ -436,8 +436,7 @@ class KeywordContributorTest extends AbstractCompletionTest {
     var keywords = <Keyword>[];
     keywords.addAll(STMT_START_OUTSIDE_CLASS);
     keywords.add(Keyword.RETHROW);
-    assertSuggestKeywords(keywords,
-        relevance: DART_RELEVANCE_KEYWORD);
+    assertSuggestKeywords(keywords, relevance: DART_RELEVANCE_KEYWORD);
   }
 
   test_class() {
@@ -1036,6 +1035,27 @@ class A {
     expect(request.replacementLength, 3);
   }
 
+  test_inComment_block() {
+    addTestSource('''
+main() {
+  /* text ^ */
+  print(42);
+}
+''');
+    expect(computeFast(), isTrue);
+    assertNoSuggestions();
+  }
+
+  test_inComment_endOfLine() {
+    addTestSource('''
+main() {
+  // text ^
+}
+''');
+    expect(computeFast(), isTrue);
+    assertNoSuggestions();
+  }
+
   test_is_expression() {
     addTestSource('main() {if (x is^)}');
     expect(computeFast(), isTrue);

pkg/analysis_server/test/services/completion/local_reference_contributor_test.dart

@@ -603,6 +603,38 @@ class B extends A {
     assertNotSuggested('MC');
   }
 
+  test_inComment_block_beforeNode() {
+    addTestSource('''
+main(aaa, bbb) {
+  /* text ^ */
+  print(42);
+}
+''');
+    expect(computeFast(), isTrue);
+    assertNoSuggestions();
+  }
+
+  test_inComment_endOfLine_beforeNode() {
+    addTestSource('''
+main(aaa, bbb) {
+  // text ^
+  print(42);
+}
+''');
+    expect(computeFast(), isTrue);
+    assertNoSuggestions();
+  }
+
+  test_inComment_endOfLine_beforeToken() {
+    addTestSource('''
+main(aaa, bbb) {
+  // text ^
+}
+''');
+    expect(computeFast(), isTrue);
+    assertNoSuggestions();
+  }
+
   test_InstanceCreationExpression() {
     addTestSource('''
 class A {foo(){var f; {var x;}}}