Add browserUrl option to Puppeteer.ConnectAsync (#917)

Author: kblok

lib/PuppeteerSharp.Tests/ConnectionTests/ConnectionTests.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Threading.Tasks;
+using System.Threading.Tasks;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -34,6 +33,59 @@ public async Task ShouldCleanCallbackList()
             await Page.SetJavaScriptEnabledAsync(true);
             Assert.False(Page.Client.HasPendingCallbacks());
         }
+
+        [Fact]
+        public async Task ShouldBeAbleToConnectUsingBrowserURLWithAndWithoutTrailingSlash()
+        {
+            var options = TestConstants.DefaultBrowserOptions();
+            options.Args = new string[] { "--remote-debugging-port=21222" };
+            var originalBrowser = await Puppeteer.LaunchAsync(options);
+            var browserURL = "http://127.0.0.1:21222";
+
+            var browser1 = await Puppeteer.ConnectAsync(new ConnectOptions { BrowserURL = browserURL });
+            var page1 = await browser1.NewPageAsync();
+            Assert.Equal(56, await page1.EvaluateExpressionAsync<int>("7 * 8"));
+            browser1.Disconnect();
+
+            var browser2 = await Puppeteer.ConnectAsync(new ConnectOptions { BrowserURL = browserURL + "/" });
+            var page2 = await browser2.NewPageAsync();
+            Assert.Equal(56, await page2.EvaluateExpressionAsync<int>("7 * 8"));
+            browser2.Disconnect();
+            await originalBrowser.CloseAsync();
+        }
+
+        [Fact]
+        public async Task ShouldThrowWhenUsingBothBrowserWSEndpointAndBrowserURL()
+        {
+            var options = TestConstants.DefaultBrowserOptions();
+            options.Args = new string[] { "--remote-debugging-port=21222" };
+            var originalBrowser = await Puppeteer.LaunchAsync(options);
+            var browserURL = "http://127.0.0.1:21222";
+
+            await Assert.ThrowsAsync<PuppeteerException>(() => Puppeteer.ConnectAsync(new ConnectOptions
+            {
+                BrowserURL = browserURL,
+                BrowserWSEndpoint = originalBrowser.WebSocketEndpoint
+            }));
+
+            await originalBrowser.CloseAsync();
+        }
+
+        [Fact]
+        public async Task ShouldThrowWhenTryingToConnectToNonExistingBrowser()
+        {
+            var options = TestConstants.DefaultBrowserOptions();
+            options.Args = new string[] { "--remote-debugging-port=21222" };
+            var originalBrowser = await Puppeteer.LaunchAsync(options);
+            var browserURL = "http://127.0.0.1:2122";
+
+            await Assert.ThrowsAsync<ChromiumProcessException>(() => Puppeteer.ConnectAsync(new ConnectOptions
+            {
+                BrowserURL = browserURL
+            }));
+
+            await originalBrowser.CloseAsync();
+        }
 
         private async Task TheSourceOfTheProblems() => await Page.Client.SendAsync("ThisCommand.DoesNotExist");
     }

lib/PuppeteerSharp/ConnectOptions.cs

@@ -27,6 +27,12 @@ public class ConnectOptions : IBrowserOptions, IConnectionOptions
         /// </summary>
         public string BrowserWSEndpoint { get; set; }
 
+        /// <summary>
+        /// A browser url to connect to, in format `http://${host}:${port}`.
+        /// Use interchangeably with `browserWSEndpoint` to let Puppeteer fetch it from <see href="https://chromedevtools.github.io/devtools-protocol/#how-do-i-access-the-browser-target">metadata endpoin</see>.
+        /// </summary>
+        public string BrowserURL { get; set; }
+        
         /// <summary>
         /// Slows down Puppeteer operations by the specified amount of milliseconds. Useful so that you can see what is going on.
         /// </summary>

lib/PuppeteerSharp/Launcher.cs

@@ -4,6 +4,8 @@
 using System.IO;
 using Microsoft.Extensions.Logging;
 using PuppeteerSharp.Messaging;
+using System.Net.Http;
+using Newtonsoft.Json;
 
 namespace PuppeteerSharp
 {
@@ -86,9 +88,18 @@ public async Task<Browser> ConnectAsync(ConnectOptions options)
         {
             EnsureSingleLaunchOrConnect();
 
+            if (!string.IsNullOrEmpty(options.BrowserURL) && !string.IsNullOrEmpty(options.BrowserWSEndpoint))
+            {
+                throw new PuppeteerException("Exactly one of browserWSEndpoint or browserURL must be passed to puppeteer.connect");
+            }
+
             try
             {
-                var connection = await Connection.Create(options.BrowserWSEndpoint, options, _loggerFactory).ConfigureAwait(false);
+                var browserWSEndpoint = string.IsNullOrEmpty(options.BrowserURL)
+                    ? options.BrowserWSEndpoint
+                    : await GetWSEndpointAsync(options.BrowserURL).ConfigureAwait(false);
+
+                var connection = await Connection.Create(browserWSEndpoint, options, _loggerFactory).ConfigureAwait(false);
                 var response = await connection.SendAsync<GetBrowserContextsResponse>("Target.getBrowserContexts");
                 return await Browser
                     .CreateAsync(connection, response.BrowserContextIds, options.IgnoreHTTPSErrors, options.DefaultViewport, null)
@@ -100,6 +111,25 @@ public async Task<Browser> ConnectAsync(ConnectOptions options)
             }
         }
 
+        private async Task<string> GetWSEndpointAsync(string browserURL)
+        {
+            try
+            {
+                if (Uri.TryCreate(new Uri(browserURL), "/json/version", out var endpointURL))
+                {
+                    var client = new HttpClient();
+                    var data = await client.GetStringAsync(endpointURL).ConfigureAwait(false);
+                    return JsonConvert.DeserializeObject<WSEndpointResponse>(data).WebSocketDebuggerUrl;
+                }
+
+                throw new PuppeteerException($"Invalid URL {browserURL}");
+            }
+            catch (Exception ex)
+            {
+                throw new PuppeteerException($"Failed to fetch browser webSocket url from {browserURL}.", ex);
+            }
+        }
+
         /// <summary>
         /// Gets the executable path.
         /// </summary>

lib/PuppeteerSharp/Messaging/WSEndpointResponse.cs

@@ -0,0 +1,7 @@
+namespace PuppeteerSharp.Messaging
+{
+    internal class WSEndpointResponse
+    {
+        public string WebSocketDebuggerUrl { get; set; }
+    }
+}