Add support for target.page for 'backgroud_page' (#593)

Author: kblok

lib/PuppeteerSharp.Tests/PuppeteerTests/HeadfulTests.cs

@@ -33,6 +33,20 @@ public async Task BackgroundPageTargetTypeShouldBeAvailable()
             }
         }
 
+        [Fact]
+        public async Task TargetPageShouldReturnABackgroundPage()
+        {
+            using (var browserWithExtension = await Puppeteer.LaunchAsync(
+                TestConstants.BrowserWithExtensionOptions(),
+                TestConstants.LoggerFactory))
+            {
+                var targets = browserWithExtension.Targets();
+                var backgroundPageTarget = targets.FirstOrDefault(target => target.Type == TargetType.BackgroundPage);
+                var page = await backgroundPageTarget.PageAsync();
+                Assert.Equal(6, await page.EvaluateFunctionAsync("() => 2 * 3"));
+            }
+        }
+
         [Fact]
         public async Task ShouldHaveDefaultUrlWhenLaunchingBrowser()
         {

lib/PuppeteerSharp/Browser.cs

@@ -80,7 +80,7 @@ public Browser(
         private readonly BrowserContext _defaultContext;
         private readonly ChromiumProcess _chromiumProcess;
         private Task _closeTask;
-        
+
         #endregion
 
         #region Properties
@@ -200,10 +200,13 @@ public BrowserContext[] BrowserContexts()
 
         /// <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>
         public async Task<Page[]> PagesAsync()
-            => (await Task.WhenAll(Targets().Select(target => target.PageAsync())).ConfigureAwait(false)).Where(x => x != null).ToArray();
+            => (await Task.WhenAll(
+                    Targets().Where(t => t.Type == TargetType.Page).Select(target => target.PageAsync())
+                ).ConfigureAwait(false)).ToArray();
 
         /// <summary>
         /// Gets the browser's version

lib/PuppeteerSharp/Target.cs

@@ -13,8 +13,8 @@ public class Target
     {
         #region Private members
         private TargetInfo _targetInfo;
-        private string _targetId;
-        private Func<TargetInfo, Task<CDPSession>> _sessionFactory;
+        private readonly string _targetId;
+        private readonly Func<TargetInfo, Task<CDPSession>> _sessionFactory;
         private Task<Page> _pageTask;
         #endregion
 
@@ -85,12 +85,12 @@ internal Target(
         #endregion
 
         /// <summary>
-        /// Creates a new <see cref="Page"/>. If the target is not <c>"page"</c> returns <c>null</c>
+        /// Creates a new <see cref="Page"/>. If the target is not <c>"page"</c> or <c>"background_page"</c> returns <c>null</c>
         /// </summary>
         /// <returns>a task that returns a new <see cref="Page"/></returns>
         public Task<Page> PageAsync()
         {
-            if (_targetInfo.Type == TargetType.Page && _pageTask == null)
+            if ((_targetInfo.Type == TargetType.Page || _targetInfo.Type == TargetType.BackgroundPage) && _pageTask == null)
             {
                 _pageTask = CreatePageAsync();
             }