[TTS] Gather surrounding text on Tap before any UX.

chrome/browser/android/contextualsearch/search_action_unittest.cc

Index: chrome/browser/android/contextualsearch/search_action_unittest.cc
diff --git a/chrome/browser/android/contextualsearch/search_action_unittest.cc b/chrome/browser/android/contextualsearch/search_action_unittest.cc
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+++ b/chrome/browser/android/contextualsearch/search_action_unittest.cc
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+// Copyright 2016 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/android/contextualsearch/search_action.h"
+
+#include "base/gtest_prod_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using base::string16;
+using base::UTF8ToUTF16;
+using std::pair;
+
+// Tests parts of the SearchAction class.
+// This is part of the 2016-refactoring (crbug.com/624609,
+// go/cs-refactoring-2016).
+class SearchActionTest : public testing::Test {
+ public:
+  SearchActionTest() {}
+  ~SearchActionTest() override {}
+
+  // The class under test.
+  std::unique_ptr<SearchAction> search_action_;
+
+ protected:
+  void SetUp() override { search_action_.reset(new SearchAction()); }
+  void TearDown() override {}
+
+  // Helper to set the context to the given sample and focus on |focus|.
+  void SetContext(std::string sample, std::string focus);
+};
+
+void SearchActionTest::SetContext(std::string sample, std::string focus) {
+  size_t offset = sample.find(focus);
+  ASSERT_NE(offset, std::string::npos);
+  search_action_->SetContext(sample, offset, offset + focus.length());
+}
+
+TEST_F(SearchActionTest, IsValidCharacterTest) {
+  EXPECT_TRUE(search_action_->IsValidCharacter('a'));
+  EXPECT_TRUE(search_action_->IsValidCharacter('A'));
+  EXPECT_TRUE(search_action_->IsValidCharacter('0'));
+
+  EXPECT_FALSE(search_action_->IsValidCharacter(','));
+  EXPECT_FALSE(search_action_->IsValidCharacter(' '));
+  EXPECT_FALSE(search_action_->IsValidCharacter('-'));
+}
+
+TEST_F(SearchActionTest, FindFocusedWordTest) {
+  // Test finding "word" within this sample string.
+  std::string sample = "Sample word, text";
+
+  // Any range inside the word but before the end should return the word.
+  search_action_->SetContext(sample, 7, 7);
+  EXPECT_EQ("word", search_action_->FindFocusedWord());
+  search_action_->SetContext(sample, 10, 10);
+  EXPECT_EQ("word", search_action_->FindFocusedWord());
+  search_action_->SetContext(sample, 7, 11);
+  EXPECT_EQ("word", search_action_->FindFocusedWord());
+
+  // A range just past the word returns an empty string.
+  search_action_->SetContext(sample, 11, 11);
+  EXPECT_EQ("", search_action_->FindFocusedWord());
+}
+
+TEST_F(SearchActionTest, SampleSurroundingsTest) {
+  std::string focus = "focus";
+  std::string sample = "987654321focus123456789";
+
+  // Sample big enough to include both ends.
+  SetContext(sample, focus);
+  EXPECT_EQ(sample, search_action_->GetSampleText(100));
+
+  // Must trim both ends, trimming 6 off each end.
+  EXPECT_EQ("321focus123", search_action_->GetSampleText(12));
+
+  // With focus near the beginning, extra is shifted to the end.
+  SetContext("321focus123456789", focus);
+  EXPECT_EQ("321focus12345", search_action_->GetSampleText(13));
+
+  // With focus near the end, extra is shifted to the beginning.
+  SetContext("987654321focus123", focus);
+  EXPECT_EQ("54321focus123", search_action_->GetSampleText(13));
+
+  // Requesting less than the focus.
+  SetContext("focus", focus);
+  EXPECT_EQ("c", search_action_->GetSampleText(1));
+}