Cancel unnecessary spellcheck requests.

chrome/renderer/spellchecker/spellcheck_provider_hunspell_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <vector>
 
 #include "base/utf_string_conversions.h"
 #include "base/stl_util.h"
 #include "chrome/common/spellcheck_messages.h"
 #include "chrome/renderer/spellchecker/spellcheck_provider.h"
@@ skipping 58 matching lines @@
   string16 text_;
   std::vector<IPC::Message*> messages_;
 };
 
 namespace {
 
 // A fake completion object for verification.
 class FakeTextCheckingCompletion : public WebKit::WebTextCheckingCompletion {
  public:
   FakeTextCheckingCompletion()
-      : completion_count_(0) {
+      : completion_count_(0),
+        cancellation_count_(0) {
   }
 
   virtual void didFinishCheckingText(
       const WebKit::WebVector<WebKit::WebTextCheckingResult>& results)
           OVERRIDE {
     ++completion_count_;
     last_results_ = results;
   }
 
+  virtual void didCancelCheckingText() OVERRIDE {
+    ++completion_count_;
+    ++cancellation_count_;
+  }
+
   size_t completion_count_;
+  size_t cancellation_count_;
   WebKit::WebVector<WebKit::WebTextCheckingResult> last_results_;
 };
 
 class SpellCheckProviderTest : public testing::Test {
  public:
   SpellCheckProviderTest() { }
   virtual ~SpellCheckProviderTest() { }
 
  protected:
   TestingSpellCheckProvider provider_;
@@ skipping 62 matching lines @@
 
   // Verify that the SpellCheckProvider class spellcheck the second line when we
   // type a period.
   provider_.ResetResult();
   provider_.RequestTextChecking(
       WebKit::WebString("First Second\nThird   Fourth."), 0, &completion);
   EXPECT_EQ(13, provider_.offset_);
   EXPECT_EQ(ASCIIToUTF16("Third   Fourth."), provider_.text_);
 }
 
+// Tests that the SpellCheckProvider class cancels incoming spellcheck requests
+// when it does not need to handle them.
+TEST_F(SpellCheckProviderTest,CancelUnnecessaryRequests) {
+  int document_tag = 123;
+  FakeTextCheckingCompletion completion;
+  provider_.RequestTextChecking(WebKit::WebString("hello."),
+                                document_tag,
+                                &completion);
+  EXPECT_EQ(completion.completion_count_, 1U);
+  EXPECT_EQ(completion.cancellation_count_, 0U);
+
+  // Test that the SpellCheckProvider class cancels an incoming request with the
+  // text same as above.
+  provider_.RequestTextChecking(WebKit::WebString("hello."),
+                                document_tag,
+                                &completion);
+  EXPECT_EQ(completion.completion_count_, 2U);
+  EXPECT_EQ(completion.cancellation_count_, 1U);
+
+  // Test that the SpellCheckProvider class cancels an incoming request that
+  // does not include any words.
+  provider_.RequestTextChecking(WebKit::WebString(":-)"),
+                                document_tag,
+                                &completion);
+  EXPECT_EQ(completion.completion_count_, 3U);
+  EXPECT_EQ(completion.cancellation_count_, 2U);
+}
+
 }  // namespace