Add BrowserContext.Pages() method (#622)

Author: kblok

lib/PuppeteerSharp.Tests/BrowserContextTests/BrowserContextTests.cs

@@ -45,7 +45,7 @@ public async Task ShouldCloseAllBelongingTargetsOnceClosingContext()
             var context = await Browser.CreateIncognitoBrowserContextAsync();
             await context.NewPageAsync();
             Assert.Equal(2, (await Browser.PagesAsync()).Length);
-
+            Assert.Single((await context.PagesAsync()));
             await context.CloseAsync();
             Assert.Single((await Browser.PagesAsync()));
         }

lib/PuppeteerSharp/Browser.cs

@@ -194,19 +194,21 @@ public BrowserContext[] BrowserContexts()
         {
             var allContexts = new BrowserContext[_contexts.Count + 1];
             allContexts[0] = _defaultContext;
-            _contexts.Values.CopyTo(allContexts, 0);
+            _contexts.Values.CopyTo(allContexts, 1);
             return allContexts;
         }
 
         /// <summary>
         /// Returns a Task which resolves to an array of all open pages.
         /// Non visible pages, such as <c>"background_page"</c>, will not be listed here. You can find them using <see cref="Target.PageAsync"/>
         /// </summary>
-        /// <returns>Task which resolves to an array of all open pages.</returns>
+        /// <returns>Task which resolves to an array of all open pages inside the Browser. 
+        /// In case of multiple browser contexts, the method will return an array with all the pages in all browser contexts.
+        /// </returns>
         public async Task<Page[]> PagesAsync()
             => (await Task.WhenAll(
-                    Targets().Where(t => t.Type == TargetType.Page).Select(target => target.PageAsync())
-                ).ConfigureAwait(false)).ToArray();
+                BrowserContexts().Select(t => t.PagesAsync())).ConfigureAwait(false)
+               ).SelectMany(p => p).ToArray();
 
         /// <summary>
         /// Gets the browser's version

lib/PuppeteerSharp/BrowserContext.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using System.Threading.Tasks;
 
 namespace PuppeteerSharp
@@ -52,6 +53,17 @@ internal BrowserContext(Browser browser, string contextId)
         /// <returns>An array of all active targets inside the browser context</returns>
         public Target[] Targets() => Array.FindAll(Browser.Targets(), target => target.BrowserContext == this);
 
+        /// <summary>
+        /// An array of all pages inside the browser context.
+        /// </summary>
+        /// <returns>Task which resolves to an array of all open pages. 
+        /// Non visible pages, such as <c>"background_page"</c>, will not be listed here. 
+        /// You can find them using <see cref="Target.PageAsync"/>.</returns>
+        public async Task<Page[]> PagesAsync()
+        => (await Task.WhenAll(
+            Targets().Where(t => t.Type == TargetType.Page).Select(t => t.PageAsync())).ConfigureAwait(false)
+           ).Where(p => p != null).ToArray();
+
         /// <summary>
         /// Creates a new page
         /// </summary>