Bidi Emulate network conditions (#3045)

Author: kblok

lib/PuppeteerSharp.Nunit/TestExpectations/TestExpectations.local.json

@@ -333,21 +333,6 @@
       "FAIL"
     ]
   },
-  {
-    "comment": "This is part of organizing the webdriver bidi implementation, We will remove it one by one",
-    "testIdPattern": "[emulation.spec] *Page.emulateNetworkConditions*",
-    "platforms": [
-      "darwin",
-      "linux",
-      "win32"
-    ],
-    "parameters": [
-      "webDriverBiDi"
-    ],
-    "expectations": [
-      "FAIL"
-    ]
-  },
   {
     "comment": "This is part of organizing the webdriver bidi implementation, We will remove it one by one",
     "testIdPattern": "[emulation.spec] *Page.emulateVision*",

lib/PuppeteerSharp/Bidi/BidiPage.cs

@@ -791,7 +791,38 @@ public override async Task SetOfflineModeAsync(bool value)
     }
 
     /// <inheritdoc />
-    public override Task EmulateNetworkConditionsAsync(NetworkConditions networkConditions) => throw new NotImplementedException();
+    public override async Task EmulateNetworkConditionsAsync(NetworkConditions networkConditions)
+    {
+        if (!BidiBrowser.CdpSupported)
+        {
+            // WebDriver BiDi supports only offline mode
+            if (networkConditions != null &&
+                !networkConditions.Offline &&
+                (networkConditions.Upload >= 0 ||
+                 networkConditions.Download >= 0 ||
+                 networkConditions.Latency > 0))
+            {
+                throw new PuppeteerException("Network throttling is not supported in this browser with WebDriver BiDi");
+            }
+
+            await BidiMainFrame.BrowsingContext.SetOfflineModeAsync(networkConditions?.Offline ?? false).ConfigureAwait(false);
+            return;
+        }
+
+        _emulatedNetworkConditions ??= new InternalNetworkConditions
+        {
+            Offline = networkConditions?.Offline ?? false,
+            Upload = -1,
+            Download = -1,
+            Latency = 0,
+        };
+
+        _emulatedNetworkConditions.Upload = networkConditions?.Upload ?? -1;
+        _emulatedNetworkConditions.Download = networkConditions?.Download ?? -1;
+        _emulatedNetworkConditions.Latency = networkConditions?.Latency ?? 0;
+        _emulatedNetworkConditions.Offline = networkConditions?.Offline ?? false;
+        await ApplyNetworkConditionsAsync().ConfigureAwait(false);
+    }
 
     /// <inheritdoc />
     public override async Task<CookieParam[]> GetCookiesAsync(params string[] urls)

lib/PuppeteerSharp/Bidi/Core/BrowsingContext.cs

@@ -224,6 +224,16 @@ internal async Task SetUserAgentAsync(string userAgent)
         await Session.Driver.Emulation.SetUserAgentOverrideAsync(parameters).ConfigureAwait(false);
     }
 
+    internal async Task SetOfflineModeAsync(bool enabled)
+    {
+        var parameters = new SetNetworkConditionsCommandParameters
+        {
+            NetworkConditions = enabled ? new NetworkConditionsOffline() : null,
+            Contexts = [Id],
+        };
+        await Session.Driver.Emulation.SetNetworkConditions(parameters).ConfigureAwait(false);
+    }
+
     protected virtual void OnBrowsingContextCreated(BidiBrowsingContextEventArgs e) => BrowsingContextCreated?.Invoke(this, e);
 
     private void Initialize()

lib/PuppeteerSharp/InternalNetworkConditions.cs

@@ -2,6 +2,5 @@ namespace PuppeteerSharp
 {
     internal class InternalNetworkConditions : NetworkConditions
     {
-        public bool Offline { get; set; }
     }
 }

lib/PuppeteerSharp/NetworkConditions.cs

@@ -25,6 +25,11 @@ public class NetworkConditions
         /// </summary>
         public const string Fast4G = "Fast 4G";
 
+        /// <summary>
+        /// Emulates the offline mode. Shortcut for <see cref="IPage.SetOfflineModeAsync(bool)"/>.
+        /// </summary>
+        public bool Offline { get; set; }
+
         /// <summary>
         /// Download speed (bytes/s), `-1` to disable.
         /// </summary>