Implement Frame.Context (#168)

Author: kblok

lib/PuppeteerSharp.Tests/Frame/ContextTests.cs

@@ -0,0 +1,36 @@
+using System.Threading.Tasks;
+using Xunit;
+
+namespace PuppeteerSharp.Tests.Frame
+{
+    [Collection("PuppeteerLoaderFixture collection")]
+    public class ContextTests : PuppeteerPageBaseTest
+    {
+        [Fact]
+        public async Task ShouldWork()
+        {
+            await Page.GoToAsync(TestConstants.EmptyPage);
+            await FrameUtils.AttachFrameAsync(Page, "frame1", TestConstants.EmptyPage);
+            Assert.Equal(2, Page.Frames.Length);
+
+            var context1 = await Page.Frames[0].GetExecutionContextAsync();
+            var context2 = await Page.Frames[1].GetExecutionContextAsync();
+            Assert.NotNull(context1);
+            Assert.NotNull(context2);
+            Assert.NotEqual(context1, context2);
+
+            await Task.WhenAll(
+                context1.EvaluateExpressionAsync("window.a = 1"),
+                context2.EvaluateExpressionAsync("window.a = 2")
+            );
+
+            var a1 = context1.EvaluateExpressionAsync<int>("window.a");
+            var a2 = context2.EvaluateExpressionAsync<int>("window.a");
+
+            await Task.WhenAll(a1, a2);
+
+            Assert.Equal(1, a1.Result);
+            Assert.Equal(2, a2.Result);
+        }
+    }
+}

lib/PuppeteerSharp/Frame.cs

@@ -74,6 +74,10 @@ public async Task<T> EvaluateFunctionAsync<T>(string script, params object[] arg
             return await context.EvaluateFunctionAsync<T>(script, args);
         }
 
+        /// <summary>
+        /// Gets the <see cref="ExecutionContext"/> associated with the frame.
+        /// </summary>
+        /// <returns><see cref="ExecutionContext"/> associated with the frame.</returns>
         public Task<ExecutionContext> GetExecutionContextAsync() => ContextResolveTaskWrapper.Task;
 
         internal async Task<ElementHandle> GetElementAsync(string selector)