testing/dart/text_test.dart

// Copyright 2019 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.

// @dart = 2.6
import 'dart:convert';
import 'dart:typed_data';
import 'dart:ui';

import 'package:test/test.dart';

void main() {
  group('FontWeight.lerp', () {
    test('works with non-null values', () {
      expect(FontWeight.lerp(FontWeight.w400, FontWeight.w600, .5), equals(FontWeight.w500));
    });

    test('returns null if a and b are null', () {
      expect(FontWeight.lerp(null, null, 0), isNull);
    });

    test('returns FontWeight.w400 if a is null', () {
      expect(FontWeight.lerp(null, FontWeight.w400, 0), equals(FontWeight.w400));
    });

    test('returns FontWeight.w400 if b is null', () {
      expect(FontWeight.lerp(FontWeight.w400, null, 1), equals(FontWeight.w400));
    });
  });

  group('ParagraphStyle', () {
    final ParagraphStyle ps0 = ParagraphStyle(textDirection: TextDirection.ltr, fontSize: 14.0);
    final ParagraphStyle ps1 = ParagraphStyle(textDirection: TextDirection.rtl, fontSize: 14.0);
    final ParagraphStyle ps2 = ParagraphStyle(textAlign: TextAlign.center, fontWeight: FontWeight.w800, fontSize: 10.0, height: 100.0);
    final ParagraphStyle ps3 = ParagraphStyle(fontWeight: FontWeight.w700, fontSize: 12.0, height: 123.0);

    test('toString works', () {
      expect(ps0.toString(), equals('ParagraphStyle(textAlign: unspecified, textDirection: TextDirection.ltr, fontWeight: unspecified, fontStyle: unspecified, maxLines: unspecified, textHeightBehavior: unspecified, fontFamily: unspecified, fontSize: 14.0, height: unspecified, ellipsis: unspecified, locale: unspecified)'));
      expect(ps1.toString(), equals('ParagraphStyle(textAlign: unspecified, textDirection: TextDirection.rtl, fontWeight: unspecified, fontStyle: unspecified, maxLines: unspecified, textHeightBehavior: unspecified, fontFamily: unspecified, fontSize: 14.0, height: unspecified, ellipsis: unspecified, locale: unspecified)'));
      expect(ps2.toString(), equals('ParagraphStyle(textAlign: TextAlign.center, textDirection: unspecified, fontWeight: FontWeight.w800, fontStyle: unspecified, maxLines: unspecified, textHeightBehavior: unspecified, fontFamily: unspecified, fontSize: 10.0, height: 100.0x, ellipsis: unspecified, locale: unspecified)'));
      expect(ps3.toString(), equals('ParagraphStyle(textAlign: unspecified, textDirection: unspecified, fontWeight: FontWeight.w700, fontStyle: unspecified, maxLines: unspecified, textHeightBehavior: unspecified, fontFamily: unspecified, fontSize: 12.0, height: 123.0x, ellipsis: unspecified, locale: unspecified)'));
    });
  });

  group('TextHeightBehavior', () {
    const TextHeightBehavior behavior0 = TextHeightBehavior();
    const TextHeightBehavior behavior1 = TextHeightBehavior(
      applyHeightToFirstAscent: false,
      applyHeightToLastDescent: false
    );
    const TextHeightBehavior behavior2 = TextHeightBehavior(
      applyHeightToFirstAscent: false,
    );
    const TextHeightBehavior behavior3 = TextHeightBehavior(
      applyHeightToLastDescent: false
    );

    test('default constructor works', () {
      expect(behavior0.applyHeightToFirstAscent, equals(true));
      expect(behavior0.applyHeightToLastDescent, equals(true));

      expect(behavior1.applyHeightToFirstAscent, equals(false));
      expect(behavior1.applyHeightToLastDescent, equals(false));

      expect(behavior2.applyHeightToFirstAscent, equals(false));
      expect(behavior2.applyHeightToLastDescent, equals(true));

      expect(behavior3.applyHeightToFirstAscent, equals(true));
      expect(behavior3.applyHeightToLastDescent, equals(false));
    });

    test('encode works', () {
      expect(behavior0.encode(), equals(0));
      expect(behavior1.encode(), equals(3));
      expect(behavior2.encode(), equals(1));
      expect(behavior3.encode(), equals(2));
    });

    test('decode works', () {
      expect(const TextHeightBehavior.fromEncoded(0), equals(behavior0));
      expect(const TextHeightBehavior.fromEncoded(3), equals(behavior1));
      expect(const TextHeightBehavior.fromEncoded(1), equals(behavior2));
      expect(const TextHeightBehavior.fromEncoded(2), equals(behavior3));
    });

    test('toString works', () {
      expect(behavior0.toString(), equals('TextHeightBehavior(applyHeightToFirstAscent: true, applyHeightToLastDescent: true)'));
      expect(behavior1.toString(), equals('TextHeightBehavior(applyHeightToFirstAscent: false, applyHeightToLastDescent: false)'));
      expect(behavior2.toString(), equals('TextHeightBehavior(applyHeightToFirstAscent: false, applyHeightToLastDescent: true)'));
      expect(behavior3.toString(), equals('TextHeightBehavior(applyHeightToFirstAscent: true, applyHeightToLastDescent: false)'));
    });
  });

  group('TextRange', () {
    test('empty ranges are correct', () {
      const TextRange range = TextRange(start: -1, end: -1);
      expect(range, equals(const TextRange.collapsed(-1)));
      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'));
    });
  });

  group('loadFontFromList', () {
    test('will send platform message after font is loaded', () async {
      final PlatformMessageCallback oldHandler = window.onPlatformMessage;
      String actualName;
      String message;
      window.onPlatformMessage = (String name, ByteData data, PlatformMessageResponseCallback callback) {
        actualName = name;
        final Uint8List list = data.buffer.asUint8List(data.offsetInBytes, data.lengthInBytes);
        message = utf8.decode(list);
      };
      final Uint8List fontData = Uint8List(0);
      await loadFontFromList(fontData, fontFamily: 'fake');
      window.onPlatformMessage = oldHandler;
      expect(actualName, 'flutter/system');
      expect(message, '{"type":"fontsChange"}');
    });
  });
}