Add IsVisibleAsync and IsHiddenAsync (#2349)

Author: kblok

lib/PuppeteerSharp.Tests/ElementHandleTests/IsVisibleIsHiddenTests.cs

@@ -0,0 +1,28 @@
+using System.Threading.Tasks;
+using PuppeteerSharp.Tests.Attributes;
+using PuppeteerSharp.Nunit;
+using NUnit.Framework;
+
+namespace PuppeteerSharp.Tests.ElementHandleTests
+{
+    public class IsVisibleIsHiddenTests : PuppeteerPageBaseTest
+    {
+        public IsVisibleIsHiddenTests() : base()
+        {
+        }
+
+        [PuppeteerTest("elementhandle.spec.ts", "ElementHandle.isVisible and ElementHandle.isHidden", "should work")]
+        [PuppeteerTimeout]
+        public async Task ShouldWork()
+        {
+            await Page.SetContentAsync("<div style='display: none'>text</div>");
+            var element = await Page.WaitForSelectorAsync("div").ConfigureAwait(false);
+            Assert.False(await element.IsVisibleAsync());
+            Assert.True(await element.IsHiddenAsync());
+
+            await element.EvaluateFunctionAsync("e => e.style.removeProperty('display')");
+            Assert.True(await element.IsVisibleAsync());
+            Assert.False(await element.IsHiddenAsync());
+        }
+    }
+}

lib/PuppeteerSharp/ElementHandle.cs

@@ -671,6 +671,33 @@ public async Task ScrollIntoViewIfNeededAsync()
             }
         }
 
+        /// <inheritdoc/>
+        public Task<bool> IsVisibleAsync() => CheckVisibilityAsync(true);
+
+        /// <inheritdoc/>
+        public Task<bool> IsHiddenAsync() => CheckVisibilityAsync(false);
+
+        private async Task<bool> CheckVisibilityAsync(bool visibility)
+        {
+            var element = await Frame.PuppeteerWorld.AdoptHandleAsync(this).ConfigureAwait(false);
+
+            try
+            {
+                return await Frame.PuppeteerWorld.EvaluateFunctionAsync<bool>(
+                    @"async (PuppeteerUtil, element, visibility) =>
+                    {
+                        return Boolean(PuppeteerUtil.checkVisibility(element, visibility));
+                    }",
+                    new LazyArg(async context => await context.GetPuppeteerUtilAsync().ConfigureAwait(false)),
+                    element,
+                    visibility).ConfigureAwait(false);
+            }
+            finally
+            {
+                await element.DisposeAsync().ConfigureAwait(false);
+            }
+        }
+
         private void CheckForFileAccess(string[] files)
         {
             foreach (var file in files)

lib/PuppeteerSharp/IElementHandle.cs

@@ -299,5 +299,17 @@ public interface IElementHandle : IJSHandle
         /// <returns>Task which resolves to an array of <see cref="IElementHandle"/>.</returns>
         [Obsolete("Use " + nameof(QuerySelectorAsync) + " instead")]
         Task<IElementHandle[]> XPathAsync(string expression);
+
+        /// <summary>
+        /// Checks if an element is visible using the same mechanism as <see cref="WaitForSelectorAsync"/>.
+        /// </summary>
+        /// <returns>Task which resolves to true if the element is visible.</returns>
+        Task<bool> IsVisibleAsync();
+
+        /// <summary>
+        /// Checks if an element is hidden using the same mechanism as <see cref="WaitForSelectorAsync"/>.
+        /// </summary>
+        /// <returns>Task which resolves to true if the element is hidden.</returns>
+        Task<bool> IsHiddenAsync();
     }
 }