packages/flutter_markdown/test/flutter_markdown_test.dart

// Copyright 2016 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.

import 'package:flutter_markdown/flutter_markdown.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter/material.dart';

void main() {
  testWidgets('Simple string', (WidgetTester tester) async {
    await tester.pumpWidget(const MarkdownBody(data: 'Hello'));

    final Iterable<Widget> widgets = tester.allWidgets;
    _expectWidgetTypes(widgets, <Type>[MarkdownBody, Column, RichText]);
    _expectTextStrings(widgets, <String>['Hello']);
  });

  testWidgets('Header', (WidgetTester tester) async {
    await tester.pumpWidget(const MarkdownBody(data: '# Header'));

    final Iterable<Widget> widgets = tester.allWidgets;
    _expectWidgetTypes(widgets, <Type>[MarkdownBody, Column, RichText]);
    _expectTextStrings(widgets, <String>['Header']);
  });

  testWidgets('Empty string', (WidgetTester tester) async {
    await tester.pumpWidget(const MarkdownBody(data: ''));

    final Iterable<Widget> widgets = tester.allWidgets;
    _expectWidgetTypes(widgets, <Type>[MarkdownBody, Column]);
  });

  testWidgets('Ordered list', (WidgetTester tester) async {
    await tester.pumpWidget(const MarkdownBody(data: '1. Item 1\n1. Item 2\n2. Item 3'));

    final Iterable<Widget> widgets = tester.allWidgets;
    _expectTextStrings(widgets, <String>[
      '1.',
      'Item 1',
      '2.',
      'Item 2',
      '3.',
      'Item 3',
    ]);
  });

  testWidgets('Unordered list', (WidgetTester tester) async {
    await tester.pumpWidget(const MarkdownBody(data: '- Item 1\n- Item 2\n- Item 3'));

    final Iterable<Widget> widgets = tester.allWidgets;
    _expectTextStrings(widgets, <String>[
      '•',
      'Item 1',
      '•',
      'Item 2',
      '•',
      'Item 3',
    ]);
  });

  testWidgets('Scrollable wrapping', (WidgetTester tester) async {
    await tester.pumpWidget(const Markdown(data: ''));

    final List<Widget> widgets = tester.allWidgets.toList();
    _expectWidgetTypes(widgets.take(2), <Type>[
      Markdown,
      ListView,
    ]);
    _expectWidgetTypes(widgets.reversed.take(2).toList().reversed, <Type>[
      SliverPadding,
      SliverList,
    ]);
  });

  testWidgets('Links', (WidgetTester tester) async {
    await tester.pumpWidget(const Markdown(data: '[Link Text](href)'));

    final RichText textWidget = tester.allWidgets.firstWhere((Widget widget) => widget is RichText);
    final TextSpan span = textWidget.text;

    expect(span.children[0].recognizer.runtimeType, equals(TapGestureRecognizer));
  });

  testWidgets('HTML tag ignored ', (WidgetTester tester) async {
    final List<String> mdData = <String>[
      'Line 1\n<p>HTML content</p>\nLine 2',
      'Line 1\n<!-- HTML\n comment\n ignored --><\nLine 2'
    ];

    for (String mdLine in mdData) {
      await tester.pumpWidget(new MarkdownBody(data: mdLine));

      final Iterable<Widget> widgets = tester.allWidgets;
      _expectTextStrings(widgets, <String>['Line 1', 'Line 2']);
    }
  });

  testWidgets('Less than', (WidgetTester tester) async {
    final String mdLine = 'Line 1 <\n\nc < c c\n\n< Line 2';
    await tester.pumpWidget(new MarkdownBody(data: mdLine));

    final Iterable<Widget> widgets = tester.allWidgets;
    _expectTextStrings(widgets, <String>['Line 1 &lt;','c &lt; c c','&lt; Line 2']);
  });

  testWidgets('Changing config - data', (WidgetTester tester) async {
    await tester.pumpWidget(const Markdown(data: 'Data1'));
    _expectTextStrings(tester.allWidgets, <String>['Data1']);

    final String stateBefore = _dumpRenderView();
    await tester.pumpWidget(const Markdown(data: 'Data1'));
    final String stateAfter = _dumpRenderView();
    expect(stateBefore, equals(stateAfter));

    await tester.pumpWidget(const Markdown(data: 'Data2'));
    _expectTextStrings(tester.allWidgets, <String>['Data2']);
  });

  testWidgets('Changing config - style', (WidgetTester tester) async {
    final ThemeData theme = new ThemeData.light();

    final MarkdownStyleSheet style1 = new MarkdownStyleSheet.fromTheme(theme);
    final MarkdownStyleSheet style2 = new MarkdownStyleSheet.largeFromTheme(theme);
    expect(style1, isNot(style2));

    await tester.pumpWidget(new Markdown(data: '# Test', styleSheet: style1));
    final RichText text1 = tester.widget(find.byType(RichText));
    await tester.pumpWidget(new Markdown(data: '# Test', styleSheet: style2));
    final RichText text2 = tester.widget(find.byType(RichText));

    expect(text1.text, isNot(text2.text));
  });

  testWidgets('Style equality', (WidgetTester tester) async {
    final ThemeData theme = new ThemeData.light();

    final MarkdownStyleSheet style1 = new MarkdownStyleSheet.fromTheme(theme);
    final MarkdownStyleSheet style2 = new MarkdownStyleSheet.fromTheme(theme);
    expect(style1, equals(style2));
    expect(style1.hashCode, equals(style2.hashCode));
  });
}

void _expectWidgetTypes(Iterable<Widget> widgets, List<Type> expected) {
  final List<Type> actual = widgets.map((Widget w) => w.runtimeType).toList();
  expect(actual, expected);
}

void _expectTextStrings(Iterable<Widget> widgets, List<String> strings) {
  int currentString = 0;
  for (Widget widget in widgets) {
    if (widget is RichText) {
      final TextSpan span = widget.text;
      final String text = _extractTextFromTextSpan(span);
      expect(text, equals(strings[currentString]));
      currentString += 1;
    }
  }
}

String _extractTextFromTextSpan(TextSpan span) {
  String text = span.text ?? '';
  if (span.children != null) {
    for (TextSpan child in span.children) {
      text += _extractTextFromTextSpan(child);
    }
  }
  return text;
}

String _dumpRenderView() {
  return WidgetsBinding.instance.renderViewElement.toStringDeep().replaceAll(
    new RegExp(r'SliverChildListDelegate#\d+', multiLine: true), 'SliverChildListDelegate'
  );
}