Record language usage as UMA histograms.

chrome/browser/language_usage_metrics_unittest.cc

+// Copyright (c) 2011 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/language_usage_metrics.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(LanguageUsageMetricsTest, ParseAcceptLanguages) {
+  std::set<Language> language_set;
+  std::set<Language>::const_iterator it;
+
+  // Basic single language case.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // Empty language.
+  LanguageUsageMetrics::ParseAcceptLanguages("", &language_set);
+  EXPECT_EQ(0U, language_set.size());
+
+  // Country code is ignored.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja-JP", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // Case is ignored.
+  LanguageUsageMetrics::ParseAcceptLanguages("Ja-jP", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // Underscore as the separator.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja_JP", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // The result contains a same language code only once.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja-JP,ja", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // Basic two languages case.
+  LanguageUsageMetrics::ParseAcceptLanguages("en,ja", &language_set);
+  EXPECT_EQ(2U, language_set.size());
+  it = language_set.begin();
+  EXPECT_EQ(ENGLISH, *it);
+  EXPECT_EQ(JAPANESE, *++it);
+
+  // Multiple languages.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja-JP,en,es,ja,en-US",
+                                             &language_set);
+  EXPECT_EQ(3U, language_set.size());
+  it = language_set.begin();
+  EXPECT_EQ(ENGLISH, *it);
+  EXPECT_EQ(JAPANESE, *++it);
+  EXPECT_EQ(SPANISH, *++it);
+
+  // Two empty languages.
+  LanguageUsageMetrics::ParseAcceptLanguages(",", &language_set);
+  EXPECT_EQ(0U, language_set.size());
+
+  // Trailing comma.
+  LanguageUsageMetrics::ParseAcceptLanguages("ja,", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(JAPANESE, *language_set.begin());
+
+  // Leading comma.
+  LanguageUsageMetrics::ParseAcceptLanguages(",es", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(SPANISH, *language_set.begin());
+
+  // Combination of invalid and valid.
+  LanguageUsageMetrics::ParseAcceptLanguages("zz,en", &language_set);
+  EXPECT_EQ(1U, language_set.size());
+  EXPECT_EQ(ENGLISH, *language_set.begin());
+}
+
+TEST(LanguageUsageMetricsTest, ToLanguage) {
+  // Basic case.
+  EXPECT_EQ(JAPANESE, LanguageUsageMetrics::ToLanguage("ja"));
+
+  // Case is ignored.
+  EXPECT_EQ(SPANISH, LanguageUsageMetrics::ToLanguage("Es"));
+
+  // Coutry code is ignored.
+  EXPECT_EQ(JAPANESE, LanguageUsageMetrics::ToLanguage("ja-JP"));
+
+  // Invalid locales are considered as unknown language.
+  EXPECT_EQ(UNKNOWN_LANGUAGE, LanguageUsageMetrics::ToLanguage(""));
+  EXPECT_EQ(UNKNOWN_LANGUAGE, LanguageUsageMetrics::ToLanguage("xx"));
+}