ui/gfx/font_fallback_win_unittest.cc - chromium/src - Git at Google

 // 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 "ui/gfx/font_fallback_win.h"

 #include <ios>
 #include <tuple>

 #include "base/macros.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/test/scoped_task_environment.h"
 #include "base/win/windows_version.h"
 #include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/icu/source/common/unicode/uchar.h"
 #include "third_party/icu/source/common/unicode/uscript.h"
 #include "third_party/icu/source/common/unicode/utf16.h"
 #include "third_party/skia/include/core/SkTypeface.h"
 #include "ui/gfx/test/font_fallback_test_data.h"

 #if defined(OS_WIN)
 #include <windows.h>
 #endif

 namespace gfx {

 namespace {

 const char kDefaultApplicationLocale[] = "us-en";

 class FontFallbackWinTest : public testing::Test {
  public:
   FontFallbackWinTest() = default;

  private:
   // Needed to bypass DCHECK in GetFallbackFont.
   base::test::ScopedTaskEnvironment scoped_task_environment_{
       base::test::ScopedTaskEnvironment::MainThreadType::UI};

   DISALLOW_COPY_AND_ASSIGN(FontFallbackWinTest);
 };

 // Options to parameterized unittests.
 struct FallbackFontTestOption {
   bool ignore_get_fallback_failure = false;
   bool skip_code_point_validation = false;
   bool skip_fallback_fonts_validation = false;
 };

 const FallbackFontTestOption default_fallback_option = {false, false, false};
 // Options for tests that does not validate the GetFallbackFont(...) parameters.
 const FallbackFontTestOption untested_fallback_option = {true, true, true};

 using FallbackFontTestParamInfo =
     std::tuple<FallbackFontTestCase, FallbackFontTestOption>;

 class GetFallbackFontTest
     : public ::testing::TestWithParam<FallbackFontTestParamInfo> {
  public:
   GetFallbackFontTest() = default;

   static std::string ParamInfoToString(
       ::testing::TestParamInfo<FallbackFontTestParamInfo> param_info) {
     const FallbackFontTestCase& test_case = std::get<0>(param_info.param);

     std::string language_tag = test_case.language_tag;
     base::RemoveChars(language_tag, "-", &language_tag);
     return std::string("S") + uscript_getName(test_case.script) + "L" +
            language_tag;
   }

   void SetUp() override { std::tie(test_case_, test_option_) = GetParam(); }

  protected:
   bool GetFallbackFont(const Font& font,
                        const std::string& language_tag,
                        Font* result) {
     return gfx::GetFallbackFont(font, language_tag, test_case_.text, result);
   }

   bool EnsuresScriptSupportCodePoints(const base::string16& text,
                                       UScriptCode script,
                                       const std::string& script_name) {
     size_t i = 0;
     while (i < text.length()) {
       UChar32 code_point;
       U16_NEXT(text.c_str(), i, text.size(), code_point);
       if (!uscript_hasScript(code_point, script)) {
         // Retrieve the appropriate script
         UErrorCode script_error;
         UScriptCode codepoint_script =
             uscript_getScript(code_point, &script_error);

         ADD_FAILURE() << "CodePoint U+" << std::hex << code_point
                       << " is not part of the script '" << script_name
                       << "'. Script '" << uscript_getName(codepoint_script)
                       << "' detected.";
         return false;
       }
     }
     return true;
   }

   bool DoesFontSupportCodePoints(Font font, const base::string16& text) {
     sk_sp<SkTypeface> skia_face =
         SkTypeface::MakeFromName(font.GetFontName().c_str(), SkFontStyle());

     size_t i = 0;
     const SkGlyphID kUnsupportedGlyph = 0;
     while (i < text.length()) {
       UChar32 code_point;
       U16_NEXT(text.c_str(), i, text.size(), code_point);
       SkGlyphID glyph_id = skia_face->unicharToGlyph(code_point);
       if (glyph_id == kUnsupportedGlyph)
         return false;
     }
     return true;
   }

   FallbackFontTestCase test_case_;
   FallbackFontTestOption test_option_;
   std::string script_name_;

  private:
   // Needed to bypass DCHECK in GetFallbackFont.
   base::test::ScopedTaskEnvironment scoped_task_environment_{
       base::test::ScopedTaskEnvironment::MainThreadType::UI};

   DISALLOW_COPY_AND_ASSIGN(GetFallbackFontTest);
 };

 }  // namespace

 TEST_F(FontFallbackWinTest, ParseFontLinkEntry) {
   std::string file;
   std::string font;

   internal::ParseFontLinkEntry("TAHOMA.TTF", &file, &font);
   EXPECT_EQ("TAHOMA.TTF", file);
   EXPECT_EQ("", font);

   internal::ParseFontLinkEntry("MSGOTHIC.TTC,MS UI Gothic", &file, &font);
   EXPECT_EQ("MSGOTHIC.TTC", file);
   EXPECT_EQ("MS UI Gothic", font);

   internal::ParseFontLinkEntry("MALGUN.TTF,128,96", &file, &font);
   EXPECT_EQ("MALGUN.TTF", file);
   EXPECT_EQ("", font);

   internal::ParseFontLinkEntry("MEIRYO.TTC,Meiryo,128,85", &file, &font);
   EXPECT_EQ("MEIRYO.TTC", file);
   EXPECT_EQ("Meiryo", font);
 }

 TEST_F(FontFallbackWinTest, ParseFontFamilyString) {
   std::vector<std::string> font_names;

   internal::ParseFontFamilyString("Times New Roman (TrueType)", &font_names);
   ASSERT_EQ(1U, font_names.size());
   EXPECT_EQ("Times New Roman", font_names[0]);
   font_names.clear();

   internal::ParseFontFamilyString("Cambria & Cambria Math (TrueType)",
                                   &font_names);
   ASSERT_EQ(2U, font_names.size());
   EXPECT_EQ("Cambria", font_names[0]);
   EXPECT_EQ("Cambria Math", font_names[1]);
   font_names.clear();

   internal::ParseFontFamilyString(
       "Meiryo & Meiryo Italic & Meiryo UI & Meiryo UI Italic (TrueType)",
       &font_names);
   ASSERT_EQ(4U, font_names.size());
   EXPECT_EQ("Meiryo", font_names[0]);
   EXPECT_EQ("Meiryo Italic", font_names[1]);
   EXPECT_EQ("Meiryo UI", font_names[2]);
   EXPECT_EQ("Meiryo UI Italic", font_names[3]);
 }

 TEST_F(FontFallbackWinTest, EmptyStringFallback) {
   Font base_font;
   Font fallback_font;
   bool result = GetFallbackFont(base_font, kDefaultApplicationLocale,
                                 base::StringPiece16(), &fallback_font);
   EXPECT_FALSE(result);
 }

 TEST_F(FontFallbackWinTest, NulTerminatedStringPiece) {
   Font base_font;
   Font fallback_font;
   // Multiple ending NUL characters.
   const wchar_t kTest1[] = {0x0540, 0x0541, 0, 0, 0};
   EXPECT_FALSE(GetFallbackFont(base_font, kDefaultApplicationLocale,
                                base::StringPiece16(kTest1, ARRAYSIZE(kTest1)),
                                &fallback_font));
   // No ending NUL character.
   const wchar_t kTest2[] = {0x0540, 0x0541};
   EXPECT_TRUE(GetFallbackFont(base_font, kDefaultApplicationLocale,
                               base::StringPiece16(kTest2, ARRAYSIZE(kTest2)),
                               &fallback_font));

   // NUL only characters.
   const wchar_t kTest3[] = {0, 0, 0};
   EXPECT_FALSE(GetFallbackFont(base_font, kDefaultApplicationLocale,
                                base::StringPiece16(kTest3, ARRAYSIZE(kTest3)),
                                &fallback_font));
 }

 TEST_F(FontFallbackWinTest, CJKLocaleFallback) {
   // The uniscribe fallback used by win7 does not support locale.
   if (base::win::GetVersion() < base::win::Version::WIN10)
     return;

   // Han unification is an effort to map multiple character sets of the CJK
   // languages into a single set of unified characters. Han characters are a
   // common feature of written Chinese (hanzi), Japanese (kanji), and Korean
   // (hanja). The same text will be rendered using a different font based on
   // locale.
   const wchar_t kCJKTest[] = L"\u8AA4\u904E\u9AA8";
   Font base_font;
   Font fallback_font;

   EXPECT_TRUE(GetFallbackFont(base_font, "zh-CN", kCJKTest, &fallback_font));
   EXPECT_EQ(fallback_font.GetFontName(), "Microsoft YaHei UI");

   EXPECT_TRUE(GetFallbackFont(base_font, "zh-TW", kCJKTest, &fallback_font));
   EXPECT_EQ(fallback_font.GetFontName(), "Microsoft JhengHei UI");

   EXPECT_TRUE(GetFallbackFont(base_font, "zh-HK", kCJKTest, &fallback_font));
   EXPECT_EQ(fallback_font.GetFontName(), "Microsoft JhengHei UI");

   EXPECT_TRUE(GetFallbackFont(base_font, "ja", kCJKTest, &fallback_font));
   EXPECT_EQ(fallback_font.GetFontName(), "Yu Gothic UI");

   EXPECT_TRUE(GetFallbackFont(base_font, "ja-JP", kCJKTest, &fallback_font));
   EXPECT_EQ(fallback_font.GetFontName(), "Yu Gothic UI");

   EXPECT_TRUE(GetFallbackFont(base_font, "ko", kCJKTest, &fallback_font));
   EXPECT_EQ(fallback_font.GetFontName(), "Malgun Gothic");

   EXPECT_TRUE(GetFallbackFont(base_font, "ko-KR", kCJKTest, &fallback_font));
   EXPECT_EQ(fallback_font.GetFontName(), "Malgun Gothic");
 }

 // This test ensures the font fallback work correctly. It will ensures that
 //   1) The script supports the text
 //   2) The input font does not already support the text
 //   3) The call to GetFallbackFont() succeed
 //   4) The fallback font has a glyph for every character of the text
 //
 // The previous checks can be activated or deactivated through the class
 // FallbackFontTestOption (e.g. test_option_).
 TEST_P(GetFallbackFontTest, GetFallbackFont) {
   // Default system font on Windows.
   const Font base_font("Segoe UI", 14);

   // Skip testing this call to GetFallbackFont on older windows versions. Some
   // fonts only got introduced on windows 10 and the test will fail on previous
   // versions.
   const bool is_win10 = base::win::GetVersion() >= base::win::Version::WIN10;
   if (test_case_.is_win10 && !is_win10)
     return;

   // Retrieve the name of the current script.
   script_name_ = uscript_getName(test_case_.script);

   // Validate that tested characters are part of the script.
   if (!test_option_.skip_code_point_validation &&
       !EnsuresScriptSupportCodePoints(test_case_.text, test_case_.script,
                                       script_name_)) {
     return;
   }

   // The default font already support it, do not try to find a fallback font.
   if (DoesFontSupportCodePoints(base_font, test_case_.text))
     return;

   // Retrieve the fallback font.
   Font fallback_font;
   bool result =
       GetFallbackFont(base_font, test_case_.language_tag, &fallback_font);
   if (!result) {
     if (!test_option_.ignore_get_fallback_failure)
       ADD_FAILURE() << "GetFallbackFont failed for '" << script_name_ << "'";
     return;
   }

   // Ensure the fallback font is a part of the validation fallback fonts list.
   if (!test_option_.skip_fallback_fonts_validation) {
     bool valid = std::find(test_case_.fallback_fonts.begin(),
                            test_case_.fallback_fonts.end(),
                            fallback_font.GetFontName()) !=
                  test_case_.fallback_fonts.end();
     if (!valid) {
       ADD_FAILURE() << "GetFallbackFont failed for '" << script_name_
                     << "' invalid fallback font: "
                     << fallback_font.GetFontName()
                     << " not among valid options: "
                     << base::JoinString(test_case_.fallback_fonts, ", ");
       return;
     }
   }

   // Ensure that glyphs exists in the fallback font.
   if (!DoesFontSupportCodePoints(fallback_font, test_case_.text)) {
     ADD_FAILURE() << "Font '" << fallback_font.GetFontName()
                   << "' does not matched every CodePoints.";
     return;
   }
 }

 // Produces a font test case for every script.
 std::vector<FallbackFontTestCase> GetSampleFontTestCases() {
   std::vector<FallbackFontTestCase> result;

   const unsigned int script_max = u_getIntPropertyMaxValue(UCHAR_SCRIPT) + 1;
   for (unsigned int i = 0; i < script_max; i++) {
     const UScriptCode script = static_cast<UScriptCode>(i);

     // Make a sample text to test the script.
     UChar text[8];
     UErrorCode errorCode = U_ZERO_ERROR;
     int text_length =
         uscript_getSampleString(script, text, ARRAYSIZE(text), &errorCode);
     if (text_length <= 0 || errorCode != U_ZERO_ERROR)
       continue;

     FallbackFontTestCase test_case(script, "", text, {});
     result.push_back(test_case);
   }
   return result;
 }

 // Ensures that the default fallback font gives known results. The test
 // is validating that a known fallback font is given for a given text and font.
 INSTANTIATE_TEST_SUITE_P(
     KnownExpectedFonts,
     GetFallbackFontTest,
     testing::Combine(testing::ValuesIn(kGetFontFallbackTests),
                      testing::Values(default_fallback_option)),
     GetFallbackFontTest::ParamInfoToString);

 // Ensures that font fallback functions are working properly for any string
 // (strings from any script). The test doesn't enforce the functions to
 // give a fallback font. The accepted behaviors are:
 //    1) The fallback function failed and doesn't provide a fallback.
 //    2) The fallback function succeeded and the font supports every glyphs.
 INSTANTIATE_TEST_SUITE_P(
     Glyphs,
     GetFallbackFontTest,
     testing::Combine(testing::ValuesIn(GetSampleFontTestCases()),
                      testing::Values(untested_fallback_option)),
     GetFallbackFontTest::ParamInfoToString);
 }  // namespace gfx
	// 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 "ui/gfx/font_fallback_win.h"

	#include <ios>
	#include <tuple>

	#include "base/macros.h"
	#include "base/strings/string_util.h"
	#include "base/strings/stringprintf.h"
	#include "base/test/scoped_task_environment.h"
	#include "base/win/windows_version.h"
	#include "build/build_config.h"
	#include "testing/gtest/include/gtest/gtest.h"
	#include "third_party/icu/source/common/unicode/uchar.h"
	#include "third_party/icu/source/common/unicode/uscript.h"
	#include "third_party/icu/source/common/unicode/utf16.h"
	#include "third_party/skia/include/core/SkTypeface.h"
	#include "ui/gfx/test/font_fallback_test_data.h"

	#if defined(OS_WIN)
	#include <windows.h>
	#endif

	namespace gfx {

	namespace {

	const char kDefaultApplicationLocale[] = "us-en";

	class FontFallbackWinTest : public testing::Test {
	public:
	FontFallbackWinTest() = default;

	private:
	// Needed to bypass DCHECK in GetFallbackFont.
	base::test::ScopedTaskEnvironment scoped_task_environment_{
	base::test::ScopedTaskEnvironment::MainThreadType::UI};

	DISALLOW_COPY_AND_ASSIGN(FontFallbackWinTest);
	};

	// Options to parameterized unittests.
	struct FallbackFontTestOption {
	bool ignore_get_fallback_failure = false;
	bool skip_code_point_validation = false;
	bool skip_fallback_fonts_validation = false;
	};

	const FallbackFontTestOption default_fallback_option = {false, false, false};
	// Options for tests that does not validate the GetFallbackFont(...) parameters.
	const FallbackFontTestOption untested_fallback_option = {true, true, true};

	using FallbackFontTestParamInfo =
	std::tuple<FallbackFontTestCase, FallbackFontTestOption>;

	class GetFallbackFontTest
	: public ::testing::TestWithParam<FallbackFontTestParamInfo> {
	public:
	GetFallbackFontTest() = default;

	static std::string ParamInfoToString(
	::testing::TestParamInfo<FallbackFontTestParamInfo> param_info) {
	const FallbackFontTestCase& test_case = std::get<0>(param_info.param);

	std::string language_tag = test_case.language_tag;
	base::RemoveChars(language_tag, "-", &language_tag);
	return std::string("S") + uscript_getName(test_case.script) + "L" +
	language_tag;
	}

	void SetUp() override { std::tie(test_case_, test_option_) = GetParam(); }

	protected:
	bool GetFallbackFont(const Font& font,
	const std::string& language_tag,
	Font* result) {
	return gfx::GetFallbackFont(font, language_tag, test_case_.text, result);
	}

	bool EnsuresScriptSupportCodePoints(const base::string16& text,
	UScriptCode script,
	const std::string& script_name) {
	size_t i = 0;
	while (i < text.length()) {
	UChar32 code_point;
	U16_NEXT(text.c_str(), i, text.size(), code_point);
	if (!uscript_hasScript(code_point, script)) {
	// Retrieve the appropriate script
	UErrorCode script_error;
	UScriptCode codepoint_script =
	uscript_getScript(code_point, &script_error);

	ADD_FAILURE() << "CodePoint U+" << std::hex << code_point
	<< " is not part of the script '" << script_name
	<< "'. Script '" << uscript_getName(codepoint_script)
	<< "' detected.";
	return false;
	}
	}
	return true;
	}

	bool DoesFontSupportCodePoints(Font font, const base::string16& text) {
	sk_sp<SkTypeface> skia_face =
	SkTypeface::MakeFromName(font.GetFontName().c_str(), SkFontStyle());

	size_t i = 0;
	const SkGlyphID kUnsupportedGlyph = 0;
	while (i < text.length()) {
	UChar32 code_point;
	U16_NEXT(text.c_str(), i, text.size(), code_point);
	SkGlyphID glyph_id = skia_face->unicharToGlyph(code_point);
	if (glyph_id == kUnsupportedGlyph)
	return false;
	}
	return true;
	}

	FallbackFontTestCase test_case_;
	FallbackFontTestOption test_option_;
	std::string script_name_;

	private:
	// Needed to bypass DCHECK in GetFallbackFont.
	base::test::ScopedTaskEnvironment scoped_task_environment_{
	base::test::ScopedTaskEnvironment::MainThreadType::UI};

	DISALLOW_COPY_AND_ASSIGN(GetFallbackFontTest);
	};

	} // namespace

	TEST_F(FontFallbackWinTest, ParseFontLinkEntry) {
	std::string file;
	std::string font;

	internal::ParseFontLinkEntry("TAHOMA.TTF", &file, &font);
	EXPECT_EQ("TAHOMA.TTF", file);
	EXPECT_EQ("", font);

	internal::ParseFontLinkEntry("MSGOTHIC.TTC,MS UI Gothic", &file, &font);
	EXPECT_EQ("MSGOTHIC.TTC", file);
	EXPECT_EQ("MS UI Gothic", font);

	internal::ParseFontLinkEntry("MALGUN.TTF,128,96", &file, &font);
	EXPECT_EQ("MALGUN.TTF", file);
	EXPECT_EQ("", font);

	internal::ParseFontLinkEntry("MEIRYO.TTC,Meiryo,128,85", &file, &font);
	EXPECT_EQ("MEIRYO.TTC", file);
	EXPECT_EQ("Meiryo", font);
	}

	TEST_F(FontFallbackWinTest, ParseFontFamilyString) {
	std::vector<std::string> font_names;

	internal::ParseFontFamilyString("Times New Roman (TrueType)", &font_names);
	ASSERT_EQ(1U, font_names.size());
	EXPECT_EQ("Times New Roman", font_names[0]);
	font_names.clear();

	internal::ParseFontFamilyString("Cambria & Cambria Math (TrueType)",
	&font_names);
	ASSERT_EQ(2U, font_names.size());
	EXPECT_EQ("Cambria", font_names[0]);
	EXPECT_EQ("Cambria Math", font_names[1]);
	font_names.clear();

	internal::ParseFontFamilyString(
	"Meiryo & Meiryo Italic & Meiryo UI & Meiryo UI Italic (TrueType)",
	&font_names);
	ASSERT_EQ(4U, font_names.size());
	EXPECT_EQ("Meiryo", font_names[0]);
	EXPECT_EQ("Meiryo Italic", font_names[1]);
	EXPECT_EQ("Meiryo UI", font_names[2]);
	EXPECT_EQ("Meiryo UI Italic", font_names[3]);
	}

	TEST_F(FontFallbackWinTest, EmptyStringFallback) {
	Font base_font;
	Font fallback_font;
	bool result = GetFallbackFont(base_font, kDefaultApplicationLocale,
	base::StringPiece16(), &fallback_font);
	EXPECT_FALSE(result);
	}

	TEST_F(FontFallbackWinTest, NulTerminatedStringPiece) {
	Font base_font;
	Font fallback_font;
	// Multiple ending NUL characters.
	const wchar_t kTest1[] = {0x0540, 0x0541, 0, 0, 0};
	EXPECT_FALSE(GetFallbackFont(base_font, kDefaultApplicationLocale,
	base::StringPiece16(kTest1, ARRAYSIZE(kTest1)),
	&fallback_font));
	// No ending NUL character.
	const wchar_t kTest2[] = {0x0540, 0x0541};
	EXPECT_TRUE(GetFallbackFont(base_font, kDefaultApplicationLocale,
	base::StringPiece16(kTest2, ARRAYSIZE(kTest2)),
	&fallback_font));

	// NUL only characters.
	const wchar_t kTest3[] = {0, 0, 0};
	EXPECT_FALSE(GetFallbackFont(base_font, kDefaultApplicationLocale,
	base::StringPiece16(kTest3, ARRAYSIZE(kTest3)),
	&fallback_font));
	}

	TEST_F(FontFallbackWinTest, CJKLocaleFallback) {
	// The uniscribe fallback used by win7 does not support locale.
	if (base::win::GetVersion() < base::win::Version::WIN10)
	return;

	// Han unification is an effort to map multiple character sets of the CJK
	// languages into a single set of unified characters. Han characters are a
	// common feature of written Chinese (hanzi), Japanese (kanji), and Korean
	// (hanja). The same text will be rendered using a different font based on
	// locale.
	const wchar_t kCJKTest[] = L"\u8AA4\u904E\u9AA8";
	Font base_font;
	Font fallback_font;

	EXPECT_TRUE(GetFallbackFont(base_font, "zh-CN", kCJKTest, &fallback_font));
	EXPECT_EQ(fallback_font.GetFontName(), "Microsoft YaHei UI");

	EXPECT_TRUE(GetFallbackFont(base_font, "zh-TW", kCJKTest, &fallback_font));
	EXPECT_EQ(fallback_font.GetFontName(), "Microsoft JhengHei UI");

	EXPECT_TRUE(GetFallbackFont(base_font, "zh-HK", kCJKTest, &fallback_font));
	EXPECT_EQ(fallback_font.GetFontName(), "Microsoft JhengHei UI");

	EXPECT_TRUE(GetFallbackFont(base_font, "ja", kCJKTest, &fallback_font));
	EXPECT_EQ(fallback_font.GetFontName(), "Yu Gothic UI");

	EXPECT_TRUE(GetFallbackFont(base_font, "ja-JP", kCJKTest, &fallback_font));
	EXPECT_EQ(fallback_font.GetFontName(), "Yu Gothic UI");

	EXPECT_TRUE(GetFallbackFont(base_font, "ko", kCJKTest, &fallback_font));
	EXPECT_EQ(fallback_font.GetFontName(), "Malgun Gothic");

	EXPECT_TRUE(GetFallbackFont(base_font, "ko-KR", kCJKTest, &fallback_font));
	EXPECT_EQ(fallback_font.GetFontName(), "Malgun Gothic");
	}

	// This test ensures the font fallback work correctly. It will ensures that
	// 1) The script supports the text
	// 2) The input font does not already support the text
	// 3) The call to GetFallbackFont() succeed
	// 4) The fallback font has a glyph for every character of the text
	//
	// The previous checks can be activated or deactivated through the class
	// FallbackFontTestOption (e.g. test_option_).
	TEST_P(GetFallbackFontTest, GetFallbackFont) {
	// Default system font on Windows.
	const Font base_font("Segoe UI", 14);

	// Skip testing this call to GetFallbackFont on older windows versions. Some
	// fonts only got introduced on windows 10 and the test will fail on previous
	// versions.
	const bool is_win10 = base::win::GetVersion() >= base::win::Version::WIN10;
	if (test_case_.is_win10 && !is_win10)
	return;

	// Retrieve the name of the current script.
	script_name_ = uscript_getName(test_case_.script);

	// Validate that tested characters are part of the script.
	if (!test_option_.skip_code_point_validation &&
	!EnsuresScriptSupportCodePoints(test_case_.text, test_case_.script,
	script_name_)) {
	return;
	}

	// The default font already support it, do not try to find a fallback font.
	if (DoesFontSupportCodePoints(base_font, test_case_.text))
	return;

	// Retrieve the fallback font.
	Font fallback_font;
	bool result =
	GetFallbackFont(base_font, test_case_.language_tag, &fallback_font);
	if (!result) {
	if (!test_option_.ignore_get_fallback_failure)
	ADD_FAILURE() << "GetFallbackFont failed for '" << script_name_ << "'";
	return;
	}

	// Ensure the fallback font is a part of the validation fallback fonts list.
	if (!test_option_.skip_fallback_fonts_validation) {
	bool valid = std::find(test_case_.fallback_fonts.begin(),
	test_case_.fallback_fonts.end(),
	fallback_font.GetFontName()) !=
	test_case_.fallback_fonts.end();
	if (!valid) {
	ADD_FAILURE() << "GetFallbackFont failed for '" << script_name_
	<< "' invalid fallback font: "
	<< fallback_font.GetFontName()
	<< " not among valid options: "
	<< base::JoinString(test_case_.fallback_fonts, ", ");
	return;
	}
	}

	// Ensure that glyphs exists in the fallback font.
	if (!DoesFontSupportCodePoints(fallback_font, test_case_.text)) {
	ADD_FAILURE() << "Font '" << fallback_font.GetFontName()
	<< "' does not matched every CodePoints.";
	return;
	}
	}

	// Produces a font test case for every script.
	std::vector<FallbackFontTestCase> GetSampleFontTestCases() {
	std::vector<FallbackFontTestCase> result;

	const unsigned int script_max = u_getIntPropertyMaxValue(UCHAR_SCRIPT) + 1;
	for (unsigned int i = 0; i < script_max; i++) {
	const UScriptCode script = static_cast<UScriptCode>(i);

	// Make a sample text to test the script.
	UChar text[8];
	UErrorCode errorCode = U_ZERO_ERROR;
	int text_length =
	uscript_getSampleString(script, text, ARRAYSIZE(text), &errorCode);
	if (text_length <= 0 \|\| errorCode != U_ZERO_ERROR)
	continue;

	FallbackFontTestCase test_case(script, "", text, {});
	result.push_back(test_case);
	}
	return result;
	}

	// Ensures that the default fallback font gives known results. The test
	// is validating that a known fallback font is given for a given text and font.
	INSTANTIATE_TEST_SUITE_P(
	KnownExpectedFonts,
	GetFallbackFontTest,
	testing::Combine(testing::ValuesIn(kGetFontFallbackTests),
	testing::Values(default_fallback_option)),
	GetFallbackFontTest::ParamInfoToString);

	// Ensures that font fallback functions are working properly for any string
	// (strings from any script). The test doesn't enforce the functions to
	// give a fallback font. The accepted behaviors are:
	// 1) The fallback function failed and doesn't provide a fallback.
	// 2) The fallback function succeeded and the font supports every glyphs.
	INSTANTIATE_TEST_SUITE_P(
	Glyphs,
	GetFallbackFontTest,
	testing::Combine(testing::ValuesIn(GetSampleFontTestCases()),
	testing::Values(untested_fallback_option)),
	GetFallbackFontTest::ParamInfoToString);
	} // namespace gfx