How to use Cancel method of PuppeteerSharp.FileChooser class

1using System;
2using System.Threading.Tasks;
3using PuppeteerSharp.Mobile;
4using Xunit;
5using Xunit.Abstractions;
6
7namespace PuppeteerSharp.Tests.InputTests
8{
9    [Collection(TestConstants.TestFixtureCollectionName)]
10    public class FileChooserCancelTests : PuppeteerPageBaseTest
11    {
12        public FileChooserCancelTests(ITestOutputHelper output) : base(output)
13        {
14        }
15
16        [Fact]
17        public async Task ShouldCancelDialog()
18        {
19            // Consider file chooser canceled if we can summon another one.
20            // There's no reliable way in WebPlatform to see that FileChooser was
21            // canceled.
22            await Page.SetContentAsync("<input type=file>");
23            var waitForTask = Page.WaitForFileChooserAsync();
24
25            await Task.WhenAll(
26                waitForTask,
27                Page.ClickAsync("input"));
28
29            var fileChooser = waitForTask.Result;
30            await fileChooser.CancelAsync();
31
32            await Task.WhenAll(
33                Page.WaitForFileChooserAsync(),
34                Page.ClickAsync("input"));
35        }
36
37        [Fact]
38        public async Task ShouldFailWhenCancelingFileChooserTwice()
39        {
40            await Page.SetContentAsync("<input type=file>");
41            var waitForTask = Page.WaitForFileChooserAsync();
42
43            await Task.WhenAll(
44                waitForTask,
45                Page.ClickAsync("input"));
46
47            var fileChooser = waitForTask.Result;
48            await fileChooser.CancelAsync();
49
50            var ex = await Assert.ThrowsAsync<PuppeteerException>(() => fileChooser.CancelAsync());
51            Assert.Equal("Cannot accept FileChooser which is already handled!", ex.Message);
52        }
53    }
54}
55

Source: FileChooserCancelTests.cs

using System;
using System.Threading.Tasks;
using PuppeteerSharp.Mobile;
using Xunit;
using Xunit.Abstractions;

namespace PuppeteerSharp.Tests.InputTests
{
    [Collection(TestConstants.TestFixtureCollectionName)]
    public class FileChooserCancelTests : PuppeteerPageBaseTest
    {
        public FileChooserCancelTests(ITestOutputHelper output) : base(output)
        {
        }

        [Fact]
        public async Task ShouldCancelDialog()
        {
            // Consider file chooser canceled if we can summon another one.
            // There's no reliable way in WebPlatform to see that FileChooser was
            // canceled.
            await Page.SetContentAsync("<input type=file>");
            var waitForTask = Page.WaitForFileChooserAsync();

            await Task.WhenAll(
                waitForTask,
                Page.ClickAsync("input"));

            var fileChooser = waitForTask.Result;
            await fileChooser.CancelAsync();

            await Task.WhenAll(
                Page.WaitForFileChooserAsync(),
                Page.ClickAsync("input"));
        }

        [Fact]
        public async Task ShouldFailWhenCancelingFileChooserTwice()
        {
            await Page.SetContentAsync("<input type=file>");
            var waitForTask = Page.WaitForFileChooserAsync();

            await Task.WhenAll(
                waitForTask,
                Page.ClickAsync("input"));

            var fileChooser = waitForTask.Result;
            await fileChooser.CancelAsync();

            var ex = await Assert.ThrowsAsync<PuppeteerException>(() => fileChooser.CancelAsync());
            Assert.Equal("Cannot accept FileChooser which is already handled!", ex.Message);
        }
    }
}