Fix SlowMo (#1151)

Author: kblok

lib/PuppeteerSharp.Tests/InputTests/KeyboardTests.cs

@@ -27,25 +27,23 @@ public async Task ShouldTypeIntoTheTextarea()
         [Fact]
         public async Task ShouldMoveWithTheArrowKeys()
         {
-            Task dummy;
-
             await Page.GoToAsync(TestConstants.ServerUrl + "/input/textarea.html");
             await Page.TypeAsync("textarea", "Hello World!");
             Assert.Equal("Hello World!", await Page.EvaluateExpressionAsync<string>("document.querySelector('textarea').value"));
             for (var i = 0; i < "World!".Length; i++)
             {
-                dummy = Page.Keyboard.PressAsync("ArrowLeft");
+                _ = Page.Keyboard.PressAsync("ArrowLeft");
             }
 
             await Page.Keyboard.TypeAsync("inserted ");
             Assert.Equal("Hello inserted World!", await Page.EvaluateExpressionAsync<string>("document.querySelector('textarea').value"));
-            dummy = Page.Keyboard.DownAsync("Shift");
+            _ = Page.Keyboard.DownAsync("Shift");
             for (var i = 0; i < "inserted ".Length; i++)
             {
-                dummy = Page.Keyboard.PressAsync("ArrowLeft");
+                _ = Page.Keyboard.PressAsync("ArrowLeft");
             }
 
-            dummy = Page.Keyboard.UpAsync("Shift");
+            _ = Page.Keyboard.UpAsync("Shift");
             await Page.Keyboard.PressAsync("Backspace");
             Assert.Equal("Hello World!", await Page.EvaluateExpressionAsync<string>("document.querySelector('textarea').value"));
         }

lib/PuppeteerSharp.Tests/Issues/Issue0716.cs

@@ -0,0 +1,30 @@
+using System.Threading.Tasks;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace PuppeteerSharp.Tests.Issues
+{
+    [Collection("PuppeteerLoaderFixture collection")]
+    public class Issue0716 : PuppeteerPageBaseTest
+    {
+        public Issue0716(ITestOutputHelper output) : base(output)
+        {
+        }
+
+        [Fact]
+        public async Task ShouldWorkInSlowMo()
+        {
+            var options = TestConstants.DefaultBrowserOptions();
+            options.SlowMo = 100;
+            options.Headless = false;
+
+            using (var browser = await Puppeteer.LaunchAsync(options))
+            using (var page = await browser.NewPageAsync())
+            {
+                await page.GoToAsync("https://duckduckgo.com/");
+                var input = await page.WaitForSelectorAsync("#search_form_input_homepage");
+                await input.TypeAsync("Lorem ipsum dolor sit amet.");
+            }
+        }
+    }
+}

lib/PuppeteerSharp/Connection.cs

@@ -19,6 +19,7 @@ namespace PuppeteerSharp
     public class Connection : IDisposable
     {
         private readonly ILogger _logger;
+        private TaskQueue _callbackQueue = new TaskQueue();
 
         internal Connection(string url, int delay, IConnectionTransport transport, ILoggerFactory loggerFactory = null)
         {
@@ -109,7 +110,7 @@ internal async Task<JObject> SendAsync(string method, object args = null, bool w
             }
 
             var id = GetMessageID();
-            
+
             MessageTask callback = null;
             if (waitForCallback)
             {
@@ -178,7 +179,9 @@ internal void Close(string closeReason)
 
         #region Private Methods
 
-        private async void Transport_MessageReceived(object sender, MessageReceivedEventArgs e)
+        private async void Transport_MessageReceived(object sender, MessageReceivedEventArgs e) => await _callbackQueue.Enqueue(() => ProcessMessage(e));
+
+        private async Task ProcessMessage(MessageReceivedEventArgs e)
         {
             try
             {