Create a new helper function to extract search terms from the URL irrespective of the availablility

chrome/browser/ui/search/instant_search_prerenderer_unittest.cc

 // Copyright 2013 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 "chrome/browser/ui/search/instant_search_prerenderer.h"
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/field_trial.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/autocomplete/autocomplete_match.h"
 #include "chrome/browser/prerender/prerender_contents.h"
 #include "chrome/browser/prerender/prerender_handle.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/prerender/prerender_manager_factory.h"
 #include "chrome/browser/prerender/prerender_origin.h"
 #include "chrome/browser/prerender/prerender_tracker.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/instant_service.h"
 #include "chrome/browser/search/instant_unittest_base.h"
 #include "chrome/browser/search/search.h"
 #include "chrome/browser/ui/search/search_tab_helper.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/render_messages.h"
+#include "chrome/common/url_constants.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/url_constants.h"
 #include "content/public/test/mock_render_process_host.h"
 #include "ipc/ipc_message.h"
 #include "ipc/ipc_test_sink.h"
 #include "ui/gfx/size.h"
 
 using base::ASCIIToUTF16;
 
@@ skipping 294 matching lines @@
   // Search results page supports Instant search. InstantSearchPrerenderer is
   // used only when the underlying page doesn't support Instant.
   NavigateAndCommitActiveTab(GURL("https://www.google.com/alt#quux=foo&strk"));
   active_tab = GetActiveWebContents();
   EXPECT_FALSE(chrome::GetSearchTermsFromURL(profile(), active_tab->GetURL())
       .empty());
   EXPECT_FALSE(chrome::ShouldPrefetchSearchResultsOnSRP());
   EXPECT_FALSE(prerenderer->IsAllowed(search_type_match, active_tab));
 }
 
+struct SearchURLTestCase {
+  const char* url;
+  const char* expected_result;
+  const char* comment;
+};
+
+TEST_F(InstantSearchPrerendererTest, GetSearchTermsFromURL) {
+  const SearchURLTestCase kTestCases[] = {
+    {chrome::kChromeSearchLocalNtpUrl,           "",    "NTP url"},
+    {"https://foo.com/instant?strk",             "",    "Invalid search url"},
+    {"https://foo.com/instant#strk",             "",    "Invalid search url"},
+    {"https://www.google.com/alt#quux=foo",      "foo", "Valid search url"},
+    {"https://www.google.com/alt#quux=foo&strk", "foo", "Valid search url"}
+  };
+
+  Init(true, true);
+  InstantSearchPrerenderer* prerenderer = GetInstantSearchPrerenderer();
+  for (size_t i = 0; i < arraysize(kTestCases); ++i) {
+    const SearchURLTestCase& test = kTestCases[i];
+    EXPECT_EQ(
+        test.expected_result,
+        UTF16ToASCII(prerenderer->GetSearchTermsFromURL(GURL(test.url))))
+            << test.url << " " << test.comment;
+  }
+}
+
 TEST_F(InstantSearchPrerendererTest, UsePrerenderPage) {
   PrerenderSearchQuery(ASCIIToUTF16("foo"));
 
   // Open a search results page. A prerendered page exists for |url|. Make sure
   // the browser swaps the current tab contents with the prerendered contents.
   GURL url("https://www.google.com/alt#quux=foo&strk");
   browser()->OpenURL(content::OpenURLParams(url, Referrer(), CURRENT_TAB,
                                             content::PAGE_TRANSITION_TYPED,
                                             false));
   EXPECT_EQ(GetPrerenderURL(), GetActiveWebContents()->GetURL());
@@ skipping 86 matching lines @@
   InstantSearchPrerenderer* prerenderer = GetInstantSearchPrerenderer();
   base::string16 query = ASCIIToUTF16("flowers");
   prerenderer->Prerender(InstantSuggestion(query, std::string()));
 
   // When the Instant search base page hasn't finished loading,
   // InstantSearchPrerenderer cannot commit any search query to the base page.
   EXPECT_FALSE(prerenderer->CanCommitQuery(GetActiveWebContents(), query));
   EXPECT_FALSE(prerenderer->CanCommitQuery(GetActiveWebContents(),
                                            ASCIIToUTF16("joy")));
 }
+
+class TestUsePrerenderPage : public InstantSearchPrerendererTest {
+ protected:
+  virtual void SetUp() OVERRIDE {
+    // Disable query extraction flag in field trials.
+    ASSERT_TRUE(base::FieldTrialList::CreateFieldTrial(
+        "EmbeddedSearch",
+        "Group1 strk:20 query_extraction:0 prefetch_results:1"));
+    InstantUnitTestBase::SetUpWithoutQueryExtraction();
+  }
+};
+
+TEST_F(TestUsePrerenderPage, ExtractSearchTermsAndUsePrerenderPage) {
+  PrerenderSearchQuery(ASCIIToUTF16("foo"));
+
+  // Open a search results page. Query extraction flag is disabled in field
+  // trials. Search results page URL does not contain search terms replacement
+  // key. Make sure UsePrerenderedPage() extracts the search terms from the URL
+  // and uses the prerendered page contents.
+  GURL url("https://www.google.com/alt#quux=foo");
+  browser()->OpenURL(content::OpenURLParams(url, Referrer(), CURRENT_TAB,
+                                            content::PAGE_TRANSITION_TYPED,
+                                            false));
+  EXPECT_EQ(GetPrerenderURL(), GetActiveWebContents()->GetURL());
+  EXPECT_EQ(static_cast<PrerenderHandle*>(NULL), prerender_handle());
+}