Implemented ElementHandle.XPathAsync (a.k.a. $x) (#212)

Meir017 · kblok · commit aa63c27a2809 · 2018-05-10T08:20:17.000-03:00
diff --git a/lib/PuppeteerSharp.Tests/ElementHandleTests/XPathTests.cs b/lib/PuppeteerSharp.Tests/ElementHandleTests/XPathTests.cs
@@ -0,0 +1,30 @@
+﻿using System.Threading.Tasks;
+using Xunit;
+
+namespace PuppeteerSharp.Tests.ElementHandleTests
+{
+    [Collection("PuppeteerLoaderFixture collection")]
+    public class XPathTests : PuppeteerPageBaseTest
+    {
+        [Fact]
+        public async Task ShouldQueryExistingElement()
+        {
+            await Page.GoToAsync(TestConstants.ServerUrl + "/playground.html");
+            await Page.SetContentAsync("<html><body><div class=\"second\"><div class=\"inner\">A</div></div></body></html>");
+            var html = await Page.QuerySelectorAsync("html");
+            var second = await html.XPathAsync("./body/div[contains(@class, 'second')]");
+            var inner = await second[0].XPathAsync("./div[contains(@class, 'inner')]");
+            var content = await Page.EvaluateFunctionAsync<string>("e => e.textContent", inner[0]);
+            Assert.Equal("A", content);
+        }
+
+        [Fact]
+        public async Task ShouldReturnNullForNonExistingElement()
+        {
+            await Page.SetContentAsync("<html><body><div class=\"second\"><div class=\"inner\">B</div></div></body></html>");
+            var html = await Page.QuerySelectorAsync("html");
+            var second = await html.XPathAsync("/div[contains(@class, 'third')]");
+            Assert.Empty(second);
+        }
+    }
+}
diff --git a/lib/PuppeteerSharp/ElementHandle.cs b/lib/PuppeteerSharp/ElementHandle.cs
@@ -139,7 +139,12 @@ internal async Task<ElementHandle[]> QuerySelectorAllAsync(string selector)
             return properties.Values.OfType<ElementHandle>().ToArray();
         }
 
-        internal async Task<ElementHandle[]> XPathAsync(string expression)
+        /// <summary>
+        /// Evaluates the XPath expression relative to the elementHandle. If there's no such element, the method will resolve to <c>null</c>.
+        /// </summary>
+        /// <param name="expression">Expression to evaluate <see cref="https://developer.mozilla.org/en-US/docs/Web/API/Document/evaluate"/></param>
+        /// <returns>Task which resolves to an array of <see cref="ElementHandle"/></returns>
+        public async Task<ElementHandle[]> XPathAsync(string expression)
         {
             var arrayHandle = await ExecutionContext.EvaluateFunctionHandleAsync(
                 @"(element, expression) => {

Original file line number	Diff line number	Diff line change
`@@ -139,7 +139,12 @@ internal async Task<ElementHandle[]> QuerySelectorAllAsync(string selector)`
`139`	`139`	`return properties.Values.OfType<ElementHandle>().ToArray();`
`140`	`140`	`}`
`141`	`141`
`142`		`- internal async Task<ElementHandle[]> XPathAsync(string expression)`
	`142`	`+ /// <summary>`
	`143`	`+ /// Evaluates the XPath expression relative to the elementHandle. If there's no such element, the method will resolve to <c>null</c>.`
	`144`	`+ /// </summary>`
	`145`	`+ /// <param name="expression">Expression to evaluate <see cref="https://developer.mozilla.org/en-US/docs/Web/API/Document/evaluate"/></param>`
	`146`	`+ /// <returns>Task which resolves to an array of <see cref="ElementHandle"/></returns>`
	`147`	`+ public async Task<ElementHandle[]> XPathAsync(string expression)`
`143`	`148`	`{`
`144`	`149`	`var arrayHandle = await ExecutionContext.EvaluateFunctionHandleAsync(`
`145`	`150`	`@"(element, expression) => {`