flutter/examples/api/test/material/button_style/button_style.0_test.dart

// Copyright 2014 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.

import 'package:flutter/material.dart';
import 'package:flutter_api_samples/material/button_style/button_style.0.dart'
    as example;
import 'package:flutter_test/flutter_test.dart';

void main() {
  testWidgets(
      'Shows ElevatedButtons, FilledButtons, OutlinedButtons and TextButtons in enabled and disabled states',
      (WidgetTester tester) async {
    await tester.pumpWidget(const example.ButtonApp());

    expect(
      find.byWidgetPredicate((Widget widget) {
        return widget is ElevatedButton && widget.onPressed == null;
      }),
      findsOne,
    );

    expect(
      find.byWidgetPredicate((Widget widget) {
        return widget is ElevatedButton && widget.onPressed != null;
      }),
      findsOne,
    );

    // One OutlinedButton with onPressed null.
    expect(
      find.byWidgetPredicate((Widget widget) {
        return widget is OutlinedButton && widget.onPressed == null;
      }),
      findsOne,
    );

    // One OutlinedButton with onPressed not null.
    expect(
      find.byWidgetPredicate((Widget widget) {
        return widget is OutlinedButton && widget.onPressed != null;
      }),
      findsOne,
    );

    expect(
      find.byWidgetPredicate((Widget widget) {
        return widget is TextButton && widget.onPressed == null;
      }),
      findsOne,
    );

    expect(
      find.byWidgetPredicate((Widget widget) {
        return widget is TextButton && widget.onPressed != null;
      }),
      findsOne,
    );

    expect(
      find.byWidgetPredicate((Widget widget) {
        return widget is FilledButton && widget.onPressed != null;
      }),
      findsNWidgets(2),
    );

    expect(
      find.byWidgetPredicate((Widget widget) {
        return widget is FilledButton && widget.onPressed == null;
      }),
      findsNWidgets(2),
    );
  });
}