Implemented Page.addScriptTag tests (#192)

Author: Meir017

lib/PuppeteerSharp.Tests/Assets/injectedfile.js

@@ -0,0 +1,2 @@
+window.__injected = 42;
+window.__injectedError = new Error('hi');

lib/PuppeteerSharp.Tests/Page/AddScriptTagTests.cs

@@ -0,0 +1,73 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace PuppeteerSharp.Tests.Page
+{
+    [Collection("PuppeteerLoaderFixture collection")]
+    public class AddScriptTagTests : PuppeteerPageBaseTest
+    {
+        [Fact]
+        public async Task ShouldThrowAnErrorIfNoOptionsAreProvided()
+        {
+            var exception = await Assert.ThrowsAsync<ArgumentException>(()
+                => Page.AddScriptTagAsync(new AddScriptTagOptions()));
+            Assert.Equal("Provide options with a `Url`, `Path` or `Content` property", exception.Message);
+        }
+
+        [Fact]
+        public async Task ShouldWorkWithAUrl()
+        {
+            await Page.GoToAsync(TestConstants.EmptyPage);
+            var scriptHandle = await Page.AddScriptTagAsync(new AddScriptTagOptions { Url = "/injectedfile.js" });
+            Assert.NotNull(scriptHandle.AsElement());
+            Assert.Equal(42, await Page.EvaluateExpressionAsync<int>("__injected"));
+        }
+
+        [Fact]
+        public async Task ShouldThrowAnErrorIfLoadingFromUrlFail()
+        {
+            await Page.GoToAsync(TestConstants.EmptyPage);
+            var exception = await Assert.ThrowsAsync<PuppeteerException>(()
+                => Page.AddScriptTagAsync(new AddScriptTagOptions { Url = "/nonexistfile.js" }));
+            Assert.Equal("Loading script from /nonexistfile.js failed", exception.Message);
+        }
+
+        [Fact]
+        public async Task ShouldWorkWithAPath()
+        {
+            await Page.GoToAsync(TestConstants.EmptyPage);
+            var scriptHandle = await Page.AddScriptTagAsync(new AddScriptTagOptions
+            {
+                Path = Path.Combine(Directory.GetCurrentDirectory(), Path.Combine("assets", "injectedfile.js"))
+            });
+            Assert.NotNull(scriptHandle.AsElement());
+            Assert.Equal(42, await Page.EvaluateExpressionAsync<int>("__injected"));
+        }
+
+        [Fact]
+        public async Task ShouldIncludeSourcemapWhenPathIsProvided()
+        {
+            await Page.GoToAsync(TestConstants.EmptyPage);
+            await Page.AddScriptTagAsync(new AddScriptTagOptions
+            {
+                Path = Path.Combine(Directory.GetCurrentDirectory(), Path.Combine("assets", "injectedfile.js"))
+            });
+            var result = await Page.EvaluateExpressionAsync<string>("__injectedError.stack");
+            Assert.Contains(Path.Combine("assets", "injectedfile.js"), result);
+        }
+
+        [Fact]
+        public async Task ShouldWorkWithContent()
+        {
+            await Page.GoToAsync(TestConstants.EmptyPage);
+            var scriptHandle = await Page.AddScriptTagAsync(new AddScriptTagOptions { Content = "window.__injected = 35;" });
+            Assert.NotNull(scriptHandle.AsElement());
+            Assert.Equal(35, await Page.EvaluateExpressionAsync<int>("__injected"));
+        }
+    }
+}

lib/PuppeteerSharp.Tests/PuppeteerSharp.Tests.csproj

@@ -22,6 +22,9 @@
     <ProjectReference Include="..\PuppeteerSharp\PuppeteerSharp.csproj" />
   </ItemGroup>
   <ItemGroup>
+    <None Update="Assets\**">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
     <None Update="test.runsettings">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>

lib/PuppeteerSharp/AddScriptTagOptions.cs

@@ -0,0 +1,23 @@
+namespace PuppeteerSharp
+{
+    /// <summary>
+    /// Options used by <see cref="Page.AddScriptTagAsync(AddScriptTagOptions)"/>
+    /// </summary>
+    public class AddScriptTagOptions
+    {
+        /// <summary>
+        /// Url of a script to be added
+        /// </summary>
+        public string Url { get; set; }
+
+        /// <summary>
+        /// Path to the JavaScript file to be injected into frame. If its a relative path, then it is resolved relative to <see cref="System.IO.Directory.GetCurrentDirectory"/>
+        /// </summary>
+        public string Path { get; set; }
+
+        /// <summary>
+        /// Raw JavaScript content to be injected into frame
+        /// </summary>
+        public string Content { get; set; }
+    }
+}

lib/PuppeteerSharp/Frame.cs

@@ -1,5 +1,8 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 
 namespace PuppeteerSharp
@@ -158,9 +161,55 @@ internal Task<ElementHandle> AddStyleTag(dynamic options)
             throw new NotImplementedException();
         }
 
-        internal Task<ElementHandle> AddScriptTag(dynamic options)
+        internal async Task<ElementHandle> AddScriptTag(AddScriptTagOptions options)
         {
-            throw new NotImplementedException();
+            const string addScriptUrl = @"async function addScriptUrl(url) {
+              const script = document.createElement('script');
+              script.src = url;
+              document.head.appendChild(script);
+              await new Promise((res, rej) => {
+                script.onload = res;
+                script.onerror = rej;
+              });
+              return script;
+            }";
+            const string addScriptContent = @"function addScriptContent(content) {
+              const script = document.createElement('script');
+              script.type = 'text/javascript';
+              script.text = content;
+              document.head.appendChild(script);
+              return script;
+            }";
+
+            if (!string.IsNullOrEmpty(options.Url))
+            {
+                var url = options.Url;
+                try
+                {
+                    var context = await GetExecutionContextAsync();
+                    return (await context.EvaluateFunctionHandleAsync(addScriptUrl, url)).AsElement();
+                }
+                catch (PuppeteerException)
+                {
+                    throw new PuppeteerException($"Loading script from {url} failed");
+                }
+            }
+
+            if (!string.IsNullOrEmpty(options.Path))
+            {
+                var contents = File.ReadAllText(options.Path, Encoding.UTF8);
+                contents += "//# sourceURL=" + options.Path.Replace("\n", string.Empty);
+                var context = await GetExecutionContextAsync();
+                return (await context.EvaluateFunctionHandleAsync(addScriptContent, contents)).AsElement();
+            }
+
+            if (!string.IsNullOrEmpty(options.Content))
+            {
+                var context = await GetExecutionContextAsync();
+                return (await context.EvaluateFunctionHandleAsync(addScriptContent, options.Content)).AsElement();
+            }
+
+            throw new ArgumentException("Provide options with a `Url`, `Path` or `Content` property");
         }
 
         internal Task<string> GetContentAsync()

lib/PuppeteerSharp/Page.cs

@@ -269,7 +269,15 @@ public async Task DeleteCookieAsync(params CookieParam[] cookies)
             }
         }
 
-        public async Task<ElementHandle> AddScriptTagAsync(dynamic options) => await MainFrame.AddScriptTag(options);
+        /// <summary>
+        /// Adds a <c><script></c> tag into the page with the desired url or content
+        /// </summary>
+        /// <param name="options">add script tag options</param>
+        /// <remarks>
+        /// Shortcut for <c>page.MainFrame.AddScriptTagAsync(options)</c>
+        /// </remarks>
+        /// <returns>Task which resolves to the added tag when the script's onload fires or when the script content was injected into frame</returns>
+        public Task<ElementHandle> AddScriptTagAsync(AddScriptTagOptions options) => MainFrame.AddScriptTag(options);
 
         public async Task<ElementHandle> AddStyleTagAsync(dynamic options) => await MainFrame.AddStyleTag(options);