lib/web_ui/test/html/text_test.dart

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// This is testing some of the named constants.
// ignore_for_file: use_named_constants

import 'package:test/bootstrap/browser.dart';
import 'package:test/test.dart';
import 'package:ui/src/engine.dart';
import 'package:ui/ui.dart';
import 'package:ui/ui_web/src/ui_web.dart' as ui_web;

import '../common/matchers.dart';
import '../common/test_initialization.dart';
import 'paragraph/helper.dart';

void main() {
  internalBootstrapBrowserTest(() => testMain);
}

Future<void> testMain() async {
  const double baselineRatio = 1.1662499904632568;

  setUpUnitTests(withImplicitView: true);

  late String fallback;
  setUp(() {
    if (operatingSystem == OperatingSystem.macOs ||
        operatingSystem == OperatingSystem.iOs) {
      if (isIOS15) {
        fallback = 'BlinkMacSystemFont';
      } else {
        fallback = '-apple-system, BlinkMacSystemFont';
      }
    } else {
      fallback = 'Arial';
    }
  });

  test('predictably lays out a single-line paragraph', () {
    for (final double fontSize in <double>[10.0, 20.0, 30.0, 40.0]) {
      final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(
        fontFamily: 'Ahem',
        fontStyle: FontStyle.normal,
        fontWeight: FontWeight.normal,
        fontSize: fontSize,
      ));
      builder.addText('Test');
      final Paragraph paragraph = builder.build();
      paragraph.layout(const ParagraphConstraints(width: 400.0));

      expect(paragraph.height, fontSize);
      expect(paragraph.width, 400.0);
      expect(paragraph.minIntrinsicWidth, fontSize * 4.0);
      expect(paragraph.maxIntrinsicWidth, fontSize * 4.0);
      expect(paragraph.alphabeticBaseline, fontSize * .8);
      expect(
        paragraph.ideographicBaseline,
        within(
            distance: 0.001,
            from: paragraph.alphabeticBaseline * baselineRatio),
      );
    }
  });

  test('predictably lays out a multi-line paragraph', () {
    for (final double fontSize in <double>[10.0, 20.0, 30.0, 40.0]) {
      final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(
        fontFamily: 'Ahem',
        fontStyle: FontStyle.normal,
        fontWeight: FontWeight.normal,
        fontSize: fontSize,
      ));
      builder.addText('Test Ahem');
      final Paragraph paragraph = builder.build();
      paragraph.layout(ParagraphConstraints(width: fontSize * 5.0));

      expect(paragraph.height, fontSize * 2.0); // because it wraps
      expect(paragraph.width, fontSize * 5.0);
      expect(paragraph.minIntrinsicWidth, fontSize * 4.0);
      expect(paragraph.maxIntrinsicWidth, fontSize * 9.0);
      expect(paragraph.alphabeticBaseline, fontSize * .8);
      expect(
        paragraph.ideographicBaseline,
        within(
            distance: 0.001,
            from: paragraph.alphabeticBaseline * baselineRatio),
      );
    }
  });

  test('Basic line related metrics', () {
    const double fontSize = 10;
    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(
      fontStyle: FontStyle.normal,
      fontWeight: FontWeight.normal,
      fontSize: fontSize,
      maxLines: 1,
      ellipsis: 'BBB',
    ))..addText('A' * 100);
    final Paragraph paragraph = builder.build();
    paragraph.layout(const ParagraphConstraints(width: 100.0));

    expect(paragraph.numberOfLines, 1);

    expect(paragraph.getLineMetricsAt(-1), isNull);
    expect(paragraph.getLineMetricsAt(0)?.lineNumber, 0);
    expect(paragraph.getLineMetricsAt(1), isNull);

    expect(paragraph.getLineNumberAt(-1), isNull);
    expect(paragraph.getLineNumberAt(0), 0);
    expect(paragraph.getLineNumberAt(6), 0);
    // The last 3 characters on the first line are ellipsized with BBB.
    expect(paragraph.getLineNumberAt(7), isNull);
  });

  test('Basic glyph metrics', () {
    const double fontSize = 10;
    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(
      fontStyle: FontStyle.normal,
      fontWeight: FontWeight.normal,
      fontSize: fontSize,
      maxLines: 1,
      ellipsis: 'BBB',
    ))..addText('A' * 100);
    final Paragraph paragraph = builder.build();
    paragraph.layout(const ParagraphConstraints(width: 100.0));

    expect(paragraph.getGlyphInfoAt(-1), isNull);

    // The last 3 characters on the first line are ellipsized with BBB.
    expect(paragraph.getGlyphInfoAt(0)?.graphemeClusterCodeUnitRange, const TextRange(start: 0, end: 1));
    expect(paragraph.getGlyphInfoAt(6)?.graphemeClusterCodeUnitRange, const TextRange(start: 6, end: 7));
    expect(paragraph.getGlyphInfoAt(7), isNull);
    expect(paragraph.getGlyphInfoAt(200), isNull);
  });

  test('Basic glyph metrics - hit test', () {
    const double fontSize = 10.0;
    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(
      fontSize: fontSize,
      fontFamily: 'FlutterTest',
    ))..addText('Test\nTest');
    final Paragraph paragraph = builder.build();
    paragraph.layout(const ParagraphConstraints(width: double.infinity));

    final GlyphInfo? bottomRight = paragraph.getClosestGlyphInfoForOffset(const Offset(99.0, 99.0));
    final GlyphInfo? last = paragraph.getGlyphInfoAt(8);
    expect(bottomRight, equals(last));
    expect(bottomRight, isNot(paragraph.getGlyphInfoAt(0)));

    expect(bottomRight?.graphemeClusterLayoutBounds, const Rect.fromLTWH(30, 10, 10, 10));
    expect(bottomRight?.graphemeClusterCodeUnitRange, const TextRange(start: 8, end: 9));
    expect(bottomRight?.writingDirection, TextDirection.ltr);
  });

  test('Basic glyph metrics - hit test - center aligned text in separate fragments', () {
    const double fontSize = 10.0;
    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(
      fontSize: fontSize,
      textAlign: TextAlign.center,
      fontFamily: 'FlutterTest',
    ))..addText('12345\n')
      ..addText('1')
      ..addText('2')
      ..addText('3');
    final Paragraph paragraph = builder.build();
    paragraph.layout(const ParagraphConstraints(width: 50));

    final GlyphInfo? bottomCenter = paragraph.getClosestGlyphInfoForOffset(const Offset(25.0, 99.0));
    final GlyphInfo? expected = paragraph.getGlyphInfoAt(7);
    expect(bottomCenter, equals(expected));
    expect(bottomCenter, isNot(paragraph.getGlyphInfoAt(8)));

    expect(bottomCenter?.graphemeClusterLayoutBounds, const Rect.fromLTWH(20, 10, 10, 10));
    expect(bottomCenter?.graphemeClusterCodeUnitRange, const TextRange(start: 7, end: 8));
    expect(bottomCenter?.writingDirection, TextDirection.ltr);
  });

  test('Glyph metrics with grapheme split into different runs', () {
    const double fontSize = 10;
    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(
      fontStyle: FontStyle.normal,
      fontWeight: FontWeight.normal,
      fontSize: fontSize,
      maxLines: 1,
    ))..addText('A') // The base charater A.
      ..addText('̀'); // The diacritical grave accent, which should combine with the base character to form a single grapheme.
    final Paragraph paragraph = builder.build();
    paragraph.layout(const ParagraphConstraints(width: double.infinity));

    expect(paragraph.getGlyphInfoAt(0)?.graphemeClusterCodeUnitRange, const TextRange(start: 0, end: 2));
    expect(paragraph.getGlyphInfoAt(0)?.graphemeClusterLayoutBounds, const Rect.fromLTWH(0.0, 0.0, 10.0, 10.0));
    expect(paragraph.getGlyphInfoAt(1)?.graphemeClusterCodeUnitRange, const TextRange(start: 0, end: 2));
    expect(paragraph.getGlyphInfoAt(1)?.graphemeClusterLayoutBounds, const Rect.fromLTWH(0.0, 0.0, 10.0, 10.0));

    final GlyphInfo? bottomRight = paragraph.getClosestGlyphInfoForOffset(const Offset(99.0, 99.0));
    expect(bottomRight?.graphemeClusterCodeUnitRange, const TextRange(start: 0, end: 2));
    expect(bottomRight?.graphemeClusterLayoutBounds, const Rect.fromLTWH(0.0, 0.0, 10.0, 10.0));
  }, skip: domIntl.v8BreakIterator == null); // Intended: Intl.v8breakiterator is needed for correctly breaking grapheme clusters.

  test('Can disable rounding hack', () {
    if (!ParagraphBuilder.shouldDisableRoundingHack) {
      ParagraphBuilder.setDisableRoundingHack(true);
      addTearDown(() => ParagraphBuilder.setDisableRoundingHack(false));
    }
    assert(ParagraphBuilder.shouldDisableRoundingHack);
    const double fontSize = 1;
    const String text = '12345';
    const double letterSpacing = 0.25;
    const double expectedIntrinsicWidth = text.length * (fontSize + letterSpacing);
    assert(expectedIntrinsicWidth.truncate() != expectedIntrinsicWidth);
    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(fontSize: fontSize, fontFamily: 'FlutterTest'));
    builder.pushStyle(TextStyle(letterSpacing: letterSpacing));
    builder.addText(text);
    final Paragraph paragraph = builder.build()
      ..layout(const ParagraphConstraints(width: expectedIntrinsicWidth));

    expect(paragraph.maxIntrinsicWidth, expectedIntrinsicWidth);
    switch (paragraph.computeLineMetrics()) {
      case [LineMetrics(width: final double width)]:
        expect(width, expectedIntrinsicWidth);
      case final List<LineMetrics> metrics:
        expect(metrics, hasLength(1));
    }
  });

  test('lay out unattached paragraph', () {
    final CanvasParagraph paragraph = plain(EngineParagraphStyle(
      fontFamily: 'sans-serif',
      fontStyle: FontStyle.normal,
      fontWeight: FontWeight.normal,
      fontSize: 14.0,
    ), 'How do you do this fine morning?');

    expect(paragraph.height, 0.0);
    expect(paragraph.width, -1.0);
    expect(paragraph.minIntrinsicWidth, 0.0);
    expect(paragraph.maxIntrinsicWidth, 0.0);
    expect(paragraph.alphabeticBaseline, -1.0);
    expect(paragraph.ideographicBaseline, -1.0);

    paragraph.layout(const ParagraphConstraints(width: 60.0));

    expect(paragraph.height, greaterThan(0.0));
    expect(paragraph.width, greaterThan(0.0));
    expect(paragraph.minIntrinsicWidth, greaterThan(0.0));
    expect(paragraph.maxIntrinsicWidth, greaterThan(0.0));
    expect(paragraph.minIntrinsicWidth, lessThan(paragraph.maxIntrinsicWidth));
    expect(paragraph.alphabeticBaseline, greaterThan(0.0));
    expect(paragraph.ideographicBaseline, greaterThan(0.0));
  });

  Paragraph measure(
      {String text = 'Hello', double fontSize = 14.0, double width = 50.0}) {
    final ParagraphBuilder builder = ParagraphBuilder(ParagraphStyle(
      fontFamily: 'sans-serif',
      fontStyle: FontStyle.normal,
      fontWeight: FontWeight.normal,
      fontSize: fontSize,
    ));
    builder.addText(text);
    final Paragraph paragraph = builder.build();
    paragraph.layout(ParagraphConstraints(width: width));
    return paragraph;
  }

  test('baseline increases with font size', () {
    Paragraph previousParagraph = measure(fontSize: 10.0);
    for (int i = 0; i < 6; i++) {
      final double fontSize = 20.0 + 10.0 * i;
      final Paragraph paragraph = measure(fontSize: fontSize);
      expect(paragraph.alphabeticBaseline,
          greaterThan(previousParagraph.alphabeticBaseline));
      expect(paragraph.ideographicBaseline,
          greaterThan(previousParagraph.ideographicBaseline));
      previousParagraph = paragraph;
    }
  });

  test('baseline does not depend on text', () {
    final Paragraph golden = measure(fontSize: 30.0);
    for (int i = 1; i < 30; i++) {
      final Paragraph paragraph = measure(text: 'hello ' * i, fontSize: 30.0);
      expect(paragraph.alphabeticBaseline, golden.alphabeticBaseline);
      expect(paragraph.ideographicBaseline, golden.ideographicBaseline);
    }
  });

  test('$ParagraphBuilder detects plain text', () {
    ParagraphBuilder builder = ParagraphBuilder(EngineParagraphStyle(
      fontFamily: 'sans-serif',
      fontStyle: FontStyle.normal,
      fontWeight: FontWeight.normal,
      fontSize: 15.0,
    ));
    builder.addText('hi');
    CanvasParagraph paragraph = builder.build() as CanvasParagraph;
    expect(paragraph.plainText, isNotNull);
    expect(paragraph.paragraphStyle.fontWeight, FontWeight.normal);

    builder = ParagraphBuilder(EngineParagraphStyle(
      fontFamily: 'sans-serif',
      fontStyle: FontStyle.normal,
      fontWeight: FontWeight.normal,
      fontSize: 15.0,
    ));
    builder.pushStyle(TextStyle(fontWeight: FontWeight.bold));
    builder.addText('hi');
    paragraph = builder.build() as CanvasParagraph;
    expect(paragraph.plainText, isNotNull);
  });

  test('$ParagraphBuilder detects rich text', () {
    final ParagraphBuilder builder = ParagraphBuilder(EngineParagraphStyle(
      fontFamily: 'sans-serif',
      fontStyle: FontStyle.normal,
      fontWeight: FontWeight.normal,
      fontSize: 15.0,
    ));
    builder.addText('h');
    builder.pushStyle(TextStyle(fontWeight: FontWeight.bold));
    builder.addText('i');
    final CanvasParagraph paragraph = builder.build() as CanvasParagraph;
    expect(paragraph.plainText, 'hi');
  });

  test('$ParagraphBuilder treats empty text as plain', () {
    final ParagraphBuilder builder = ParagraphBuilder(EngineParagraphStyle(
      fontFamily: 'sans-serif',
      fontStyle: FontStyle.normal,
      fontWeight: FontWeight.normal,
      fontSize: 15.0,
    ));
    builder.pushStyle(TextStyle(fontWeight: FontWeight.bold));
    final CanvasParagraph paragraph = builder.build() as CanvasParagraph;
    expect(paragraph.plainText, '');
  });

  // Regression test for https://github.com/flutter/flutter/issues/38972
  test(
      'should not set fontFamily to effectiveFontFamily for spans in rich text',
      () {
    final ParagraphBuilder builder = ParagraphBuilder(EngineParagraphStyle(
      fontFamily: 'Roboto',
      fontStyle: FontStyle.normal,
      fontWeight: FontWeight.normal,
      fontSize: 15.0,
    ));
    builder
        .pushStyle(TextStyle(fontFamily: 'Menlo', fontWeight: FontWeight.bold));
    const String firstSpanText = 'abc';
    builder.addText(firstSpanText);
    builder.pushStyle(TextStyle(fontSize: 30.0, fontWeight: FontWeight.normal));
    const String secondSpanText = 'def';
    builder.addText(secondSpanText);
    final CanvasParagraph paragraph = builder.build() as CanvasParagraph;
    paragraph.layout(const ParagraphConstraints(width: 800.0));
    expect(paragraph.plainText, 'abcdef');
    final List<DomElement> spans =
        paragraph.toDomElement().querySelectorAll('flt-span').toList();
    expect(spans[0].style.fontFamily, 'FlutterTest, $fallback, sans-serif');
    // The nested span here should not set it's family to default sans-serif.
    expect(spans[1].style.fontFamily, 'FlutterTest, $fallback, sans-serif');
  },
      // TODO(mdebbar): https://github.com/flutter/flutter/issues/46638
      skip: browserEngine == BrowserEngine.firefox);

  test('adds Arial and sans-serif as fallback fonts', () {
    // Set this to false so it doesn't default to the test font.
    ui_web.debugEmulateFlutterTesterEnvironment = false;

    final CanvasParagraph paragraph = plain(EngineParagraphStyle(
      fontFamily: 'SomeFont',
      fontSize: 12.0,
    ), 'Hello');

    paragraph.layout(constrain(double.infinity));
    expect(paragraph.toDomElement().children.single.style.fontFamily,
        'SomeFont, $fallback, sans-serif');

    ui_web.debugEmulateFlutterTesterEnvironment = true;
  },
      // TODO(mdebbar): https://github.com/flutter/flutter/issues/46638
      skip: browserEngine == BrowserEngine.firefox);

  test('does not add fallback fonts to generic families', () {
    // Set this to false so it doesn't default to the default test font.
    ui_web.debugEmulateFlutterTesterEnvironment = false;

    final CanvasParagraph paragraph = plain(EngineParagraphStyle(
      fontFamily: 'serif',
      fontSize: 12.0,
    ), 'Hello');

    paragraph.layout(constrain(double.infinity));
    expect(paragraph.toDomElement().children.single.style.fontFamily, 'serif');

    ui_web.debugEmulateFlutterTesterEnvironment = true;
  });

  test('can set font families that need to be quoted', () {
    // Set this to false so it doesn't default to the default test font.
    ui_web.debugEmulateFlutterTesterEnvironment = false;

    final CanvasParagraph paragraph = plain(EngineParagraphStyle(
      fontFamily: 'MyFont 2000',
      fontSize: 12.0,
    ), 'Hello');

    paragraph.layout(constrain(double.infinity));
    expect(paragraph.toDomElement().children.single.style.fontFamily,
        '"MyFont 2000", $fallback, sans-serif');

    ui_web.debugEmulateFlutterTesterEnvironment = true;
  });

  group('TextRange', () {
    test('empty ranges are correct', () {
      const TextRange range = TextRange(start: -1, end: -1);
      expect(range, equals(TextRange.collapsed(-1))); // ignore: prefer_const_constructors
      expect(range, equals(TextRange.empty));
    });
    test('isValid works', () {
      expect(TextRange.empty.isValid, isFalse);
      expect(const TextRange(start: 0, end: 0).isValid, isTrue);
      expect(const TextRange(start: 0, end: 10).isValid, isTrue);
      expect(const TextRange(start: 10, end: 10).isValid, isTrue);
      expect(const TextRange(start: -1, end: 10).isValid, isFalse);
      expect(const TextRange(start: 10, end: 0).isValid, isTrue);
      expect(const TextRange(start: 10, end: -1).isValid, isFalse);
    });
    test('isCollapsed works', () {
      expect(TextRange.empty.isCollapsed, isTrue);
      expect(const TextRange(start: 0, end: 0).isCollapsed, isTrue);
      expect(const TextRange(start: 0, end: 10).isCollapsed, isFalse);
      expect(const TextRange(start: 10, end: 10).isCollapsed, isTrue);
      expect(const TextRange(start: -1, end: 10).isCollapsed, isFalse);
      expect(const TextRange(start: 10, end: 0).isCollapsed, isFalse);
      expect(const TextRange(start: 10, end: -1).isCollapsed, isFalse);
    });
    test('isNormalized works', () {
      expect(TextRange.empty.isNormalized, isTrue);
      expect(const TextRange(start: 0, end: 0).isNormalized, isTrue);
      expect(const TextRange(start: 0, end: 10).isNormalized, isTrue);
      expect(const TextRange(start: 10, end: 10).isNormalized, isTrue);
      expect(const TextRange(start: -1, end: 10).isNormalized, isTrue);
      expect(const TextRange(start: 10, end: 0).isNormalized, isFalse);
      expect(const TextRange(start: 10, end: -1).isNormalized, isFalse);
    });
    test('textBefore works', () {
      expect(const TextRange(start: 0, end: 0).textBefore('hello'), isEmpty);
      expect(
          const TextRange(start: 1, end: 1).textBefore('hello'), equals('h'));
      expect(
          const TextRange(start: 1, end: 2).textBefore('hello'), equals('h'));
      expect(const TextRange(start: 5, end: 5).textBefore('hello'),
          equals('hello'));
      expect(const TextRange(start: 0, end: 5).textBefore('hello'), isEmpty);
    });
    test('textAfter works', () {
      expect(const TextRange(start: 0, end: 0).textAfter('hello'),
          equals('hello'));
      expect(
          const TextRange(start: 1, end: 1).textAfter('hello'), equals('ello'));
      expect(
          const TextRange(start: 1, end: 2).textAfter('hello'), equals('llo'));
      expect(const TextRange(start: 5, end: 5).textAfter('hello'), isEmpty);
      expect(const TextRange(start: 0, end: 5).textAfter('hello'), isEmpty);
    });
    test('textInside works', () {
      expect(const TextRange(start: 0, end: 0).textInside('hello'), isEmpty);
      expect(const TextRange(start: 1, end: 1).textInside('hello'), isEmpty);
      expect(
          const TextRange(start: 1, end: 2).textInside('hello'), equals('e'));
      expect(const TextRange(start: 5, end: 5).textInside('hello'), isEmpty);
      expect(const TextRange(start: 0, end: 5).textInside('hello'),
          equals('hello'));
    });
  });

  test('FontWeights have the correct value', () {
    expect(FontWeight.w100.value, 100);
    expect(FontWeight.w200.value, 200);
    expect(FontWeight.w300.value, 300);
    expect(FontWeight.w400.value, 400);
    expect(FontWeight.w500.value, 500);
    expect(FontWeight.w600.value, 600);
    expect(FontWeight.w700.value, 700);
    expect(FontWeight.w800.value, 800);
    expect(FontWeight.w900.value, 900);
  });

  group('test fonts in flutterTester environment', () {
    final bool resetValue = ui_web.debugEmulateFlutterTesterEnvironment;
    ui_web.debugEmulateFlutterTesterEnvironment = true;
    tearDownAll(() {
      ui_web.debugEmulateFlutterTesterEnvironment = resetValue;
    });
    const List<String> testFonts = <String>['FlutterTest', 'Ahem'];

    test('The default test font is used when a non-test fontFamily is specified, or fontFamily is not specified', () {
      final String defaultTestFontFamily = testFonts.first;

      expect(EngineTextStyle.only().effectiveFontFamily, defaultTestFontFamily);
      expect(EngineTextStyle.only(fontFamily: 'BogusFontFamily').effectiveFontFamily, defaultTestFontFamily);
    });

    test('Can specify test fontFamily to use', () {
      for (final String testFont in testFonts) {
        expect(EngineTextStyle.only(fontFamily: testFont).effectiveFontFamily, testFont);
      }
    });
  });
}