flutter_flutter/engine/platform/text/BidiResolverTest.cpp

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#include "sky/engine/config.h"
#include "sky/engine/platform/text/BidiResolver.h"

#include <gtest/gtest.h>
#include <fstream>
#include "sky/engine/platform/text/BidiTestHarness.h"
#include "sky/engine/platform/text/TextRunIterator.h"
#include "sky/engine/wtf/OwnPtr.h"

namespace {

using namespace WTF;
using namespace blink;

TEST(BidiResolver, Basic)
{
    bool hasStrongDirectionality;
    String value("foo");
    TextRun run(value);
    BidiResolver<TextRunIterator, BidiCharacterRun> bidiResolver;
    bidiResolver.setStatus(BidiStatus(run.direction(), run.directionalOverride()));
    bidiResolver.setPositionIgnoringNestedIsolates(TextRunIterator(&run, 0));
    TextDirection direction = bidiResolver.determineParagraphDirectionality(&hasStrongDirectionality);
    EXPECT_TRUE(hasStrongDirectionality);
    EXPECT_EQ(LTR, direction);
}

TextDirection determineParagraphDirectionality(const TextRun& textRun, bool* hasStrongDirectionality = 0)
{
    BidiResolver<TextRunIterator, BidiCharacterRun> resolver;
    resolver.setStatus(BidiStatus(LTR, false));
    resolver.setPositionIgnoringNestedIsolates(TextRunIterator(&textRun, 0));
    return resolver.determineParagraphDirectionality(hasStrongDirectionality);
}

struct TestData {
    UChar text[3];
    size_t length;
    TextDirection expectedDirection;
    bool expectedStrong;
};

void testDirectionality(const TestData& entry)
{
    bool hasStrongDirectionality;
    String data(entry.text, entry.length);
    TextRun run(data);
    TextDirection direction = determineParagraphDirectionality(run, &hasStrongDirectionality);
    EXPECT_EQ(entry.expectedStrong, hasStrongDirectionality);
    EXPECT_EQ(entry.expectedDirection, direction);
}

TEST(BidiResolver, ParagraphDirectionSurrogates)
{
    const TestData testData[] = {
        // Test strong RTL, non-BMP. (U+10858 Imperial Aramaic number one, strong RTL)
        { { 0xD802, 0xDC58 }, 2, RTL, true },

        // Test strong LTR, non-BMP. (U+1D15F Musical symbol quarter note, strong LTR)
        { { 0xD834, 0xDD5F }, 2, LTR, true },

        // Test broken surrogate: valid leading, invalid trail. (Lead of U+10858, space)
        { { 0xD802, ' ' }, 2, LTR, false },

        // Test broken surrogate: invalid leading. (Trail of U+10858, U+05D0 Hebrew Alef)
        { { 0xDC58, 0x05D0 }, 2, RTL, true },

        // Test broken surrogate: valid leading, invalid trail/valid lead, valid trail.
        { { 0xD802, 0xD802, 0xDC58 }, 3, RTL, true },

        // Test broken surrogate: valid leading, no trail (string too short). (Lead of U+10858)
        { { 0xD802, 0xDC58 }, 1, LTR, false },

        // Test broken surrogate: trail appearing before lead. (U+10858 units reversed)
        { { 0xDC58, 0xD802 }, 2, LTR, false }
    };
    for (size_t i = 0; i < WTF_ARRAY_LENGTH(testData); ++i)
        testDirectionality(testData[i]);
}

class BidiTestRunner {
public:
    BidiTestRunner()
        : m_testsRun(0)
        , m_testsSkipped(0)
        , m_ignoredCharFailures(0)
        , m_levelFailures(0)
        , m_orderFailures(0)
    {
    }

    void skipTestsWith(UChar codepoint)
    {
        m_skippedCodePoints.insert(codepoint);
    }

    void runTest(const std::basic_string<UChar>& input, const std::vector<int>& reorder,
        const std::vector<int>& levels, bidi_test::ParagraphDirection,
        const std::string& line, size_t lineNumber);

    size_t m_testsRun;
    size_t m_testsSkipped;
    std::set<UChar> m_skippedCodePoints;
    size_t m_ignoredCharFailures;
    size_t m_levelFailures;
    size_t m_orderFailures;
};

// Blink's UBA does not filter out control characters, etc. Maybe it should?
// Instead it depends on later layers of Blink to simply ignore them.
// This function helps us emulate that to be compatible with BidiTest.txt expectations.
static bool isNonRenderedCodePoint(UChar c)
{
    // The tests also expect us to ignore soft-hyphen.
    if (c == 0xAD)
        return true;
    // Control characters are not rendered:
    return c >= 0x202A && c <= 0x202E;
    // But it seems to expect LRI, etc. to be rendered!?
}

std::string diffString(const std::vector<int>& actual, const std::vector<int>& expected)
{
    std::ostringstream diff;
    diff << "actual: ";
    // This is the magical way to print a vector to a stream, clear, right?
    std::copy(actual.begin(), actual.end(), std::ostream_iterator<int>(diff, " "));
    diff << " expected: ";
    std::copy(expected.begin(), expected.end(), std::ostream_iterator<int>(diff, " "));
    return diff.str();
}

void BidiTestRunner::runTest(const std::basic_string<UChar>& input, const std::vector<int>& expectedOrder,
    const std::vector<int>& expectedLevels, bidi_test::ParagraphDirection paragraphDirection,
    const std::string& line, size_t lineNumber)
{
    if (!m_skippedCodePoints.empty()) {
        for (size_t i = 0; i < input.size(); i++) {
            if (m_skippedCodePoints.count(input[i])) {
                m_testsSkipped++;
                return;
            }
        }
    }

    m_testsRun++;

    TextRun textRun(input.data(), input.size());
    switch (paragraphDirection) {
    case bidi_test::DirectionAutoLTR:
        textRun.setDirection(determineParagraphDirectionality(textRun));
        break;
    case bidi_test::DirectionLTR:
        textRun.setDirection(LTR);
        break;
    case bidi_test::DirectionRTL:
        textRun.setDirection(RTL);
        break;
    }
    BidiResolver<TextRunIterator, BidiCharacterRun> resolver;
    resolver.setStatus(BidiStatus(textRun.direction(), textRun.directionalOverride()));
    resolver.setPositionIgnoringNestedIsolates(TextRunIterator(&textRun, 0));

    BidiRunList<BidiCharacterRun>& runs = resolver.runs();
    resolver.createBidiRunsForLine(TextRunIterator(&textRun, textRun.length()));

    std::ostringstream errorContext;
    errorContext << ", line " << lineNumber << " \"" << line << "\"";
    errorContext << " context: " << bidi_test::nameFromParagraphDirection(paragraphDirection);

    std::vector<int> actualOrder;
    std::vector<int> actualLevels;
    actualLevels.assign(input.size(), -1);
    BidiCharacterRun* run = runs.firstRun();
    while (run) {
        // Blink's UBA just makes runs, the actual ordering of the display of characters
        // is handled later in our pipeline, so we fake it here:
        bool reversed = run->reversed();
        ASSERT(run->stop() >= run->start());
        size_t length = run->stop() - run->start();
        for (size_t i = 0; i < length; i++) {
            int inputIndex = reversed ? run->stop() - i - 1 : run->start() + i;
            if (!isNonRenderedCodePoint(input[inputIndex]))
                actualOrder.push_back(inputIndex);
            // BidiTest.txt gives expected level data in the order of the original input.
            actualLevels[inputIndex] = run->level();
        }
        run = run->next();
    }

    if (expectedOrder.size() != actualOrder.size()) {
        m_ignoredCharFailures++;
        EXPECT_EQ(expectedOrder.size(), actualOrder.size()) << errorContext.str();
    } else if (expectedOrder != actualOrder) {
        m_orderFailures++;
        printf("ORDER %s%s\n", diffString(actualOrder, expectedOrder).c_str(), errorContext.str().c_str());
    }

    if (expectedLevels.size() != actualLevels.size()) {
        m_ignoredCharFailures++;
        EXPECT_EQ(expectedLevels.size(), actualLevels.size()) << errorContext.str();
    } else {
        for (size_t i = 0; i < expectedLevels.size(); i++) {
            // level == -1 means the level should be ignored.
            if (expectedLevels[i] == actualLevels[i] || expectedLevels[i] == -1)
                continue;

            printf("LEVELS %s%s\n", diffString(actualLevels, expectedLevels).c_str(), errorContext.str().c_str());
            m_levelFailures++;
            break;
        }
    }
    runs.deleteRuns();
}


TEST(BidiResolver, BidiTest_txt)
{
    BidiTestRunner runner;
    // Blink's Unicode Bidi Algorithm (UBA) doesn't yet support the
    // new isolate directives from Unicode 6.3:
    // http://www.unicode.org/reports/tr9/#Explicit_Directional_Isolates
    runner.skipTestsWith(0x2066); // LRI
    runner.skipTestsWith(0x2067); // RLI
    runner.skipTestsWith(0x2068); // FSI
    runner.skipTestsWith(0x2069); // PDI

    // This code wants to use PathService from base/path_service.h
    // but we aren't allowed to depend on base/ directly from Blink yet.
    // Alternatively we could use:
    // blink::Platform::current()->unitTestSupport()->webKitRootDir()
    // and a relative path, but that would require running inside
    // webkit_unit_tests (to have a functioning Platform object).
    // The file we want is:
    // src/third_party/icu/source/test/testdata/BidiTest.txt
    // but we don't have any good way to find it from this unittest.
    // Just assume we're running this test manually for now. On the
    // bots we just print a warning that we can't find the test file.
    std::string bidiTestPath = "BidiTest.txt";
    std::ifstream bidiTestFile(bidiTestPath.c_str());
    if (!bidiTestFile.is_open()) {
        printf("ERROR: Failed to open BidiTest.txt, cannot run tests.\n");
        return;
    }

    bidi_test::Harness<BidiTestRunner> harness(runner);
    harness.parse(bidiTestFile);
    bidiTestFile.close();

    if (runner.m_testsSkipped)
        printf("WARNING: Skipped %zu tests.\n", runner.m_testsSkipped);
    printf("Ran %zu tests: %zu level failures %zu order failures.\n",
        runner.m_testsRun, runner.m_levelFailures, runner.m_orderFailures);

    // The unittest harness only pays attention to GTest output, so we verify
    // that the tests behaved as expected:
    EXPECT_EQ(352098u, runner.m_testsRun);
    EXPECT_EQ(418143u, runner.m_testsSkipped);
    EXPECT_EQ(0u, runner.m_ignoredCharFailures);
    EXPECT_EQ(44882u, runner.m_levelFailures);
    EXPECT_EQ(19151u, runner.m_orderFailures);
}

}