Better live reload handling in malformed HTML files

RELEASE.md

@@ -3,6 +3,7 @@
 - Added a new `AdditionalInputFiles` setting that can be used to explicitly include input files that would otherwise be excluded by the `InputFiles` setting such as underscore files.
 - Updated the `NetlifyRedirects` setting so that when `true`, any existing Netlify-style `_redirects` file will be output (underscore files are normally excluded by default).
 - Added a new `NetlifyPrefixRedirects` setting (`true` by default) that will automatically create redirect entries to files and folders that are prefixed with a specific value (`^` by default) from requests without the prefix. This is helpful when needing to publish files or folder prefixed with a `.` since [Netlify deployment doesn't support them](https://answers.netlify.com/t/netlify-deploy-api-removes-files-and-directories-beginning-with-a-period/37728/9) (#1002).
+- Improved script injection behavior (I.e. for live reload support) when the HTML document deviates from standards (I.e. directly after Markdown rendering).
 
 # 1.0.0-beta.52
 

src/Statiq.Web.Hosting/Middleware/ScriptInjectionMiddleware.cs

@@ -40,17 +40,34 @@ public async Task InvokeAsync(HttpContext context)
             if (string.Equals(context.Response.ContentType, "text/html", StringComparison.OrdinalIgnoreCase))
             {
                 StreamReader reader = new StreamReader(interceptedBody);
-                string body = await reader.ReadToEndAsync();
-                int closingTag = body.LastIndexOf("</body>", StringComparison.Ordinal);
-                if (closingTag > -1)
-                {
-                    interceptedBody = new MemoryStream(reader.CurrentEncoding.GetBytes(body.Insert(closingTag, _injectionCode)));
-                    context.Response.ContentLength = interceptedBody.Length;
-                }
+                string document = await reader.ReadToEndAsync();
+                int injectionPosition = GetInjectionPosition(document);
+                interceptedBody = new MemoryStream(reader.CurrentEncoding.GetBytes(document.Insert(injectionPosition, _injectionCode)));
+                context.Response.ContentLength = interceptedBody.Length;
             }
             interceptedBody.Position = 0;
             await interceptedBody.CopyToAsync(originalBody);
             context.Response.Body = originalBody;
         }
+
+        private int GetInjectionPosition(string document)
+        {
+            // Try for the </body> tag first
+            int position = document.LastIndexOf("</body", StringComparison.OrdinalIgnoreCase);
+
+            // If we didn't find a body, try for the </html> tag
+            if (position == -1)
+            {
+                position = document.LastIndexOf("</html", StringComparison.OrdinalIgnoreCase);
+            }
+
+            // If we didn't find a body or html, just inject at the end
+            if (position == -1)
+            {
+                position = document.Length;
+            }
+
+            return position;
+        }
     }
 }

tests/Statiq.Web.Hosting.Tests/Middleware/ScriptInjectionMiddlewareTests.cs

@@ -15,10 +15,10 @@ namespace Statiq.Web.Hosting.Tests.Middleware
     [TestFixture]
     public class ScriptInjectionMiddlewareTests
     {
-        [TestCase("BasicHtmlDocument.html", true)]
-        [TestCase("BasicHtmlDocumentNoBodyEnd.html", false)]
-        [TestCase("NonHtmlDocument.css", false)]
-        public async Task InjectScriptWhenAppropriate(string filename, bool inject)
+        [TestCase("BasicHtmlDocument.html", "<script type=\"text/javascript\" src=\"/livereload.js\"></script></body>", 151)]
+        [TestCase("BasicHtmlDocumentNoBody.html", "<script type=\"text/javascript\" src=\"/livereload.js\"></script></html>", 146)]
+        [TestCase("BasicHtmlDocumentNoHtml.html", "<script type=\"text/javascript\" src=\"/livereload.js\"></script>", 89)]
+        public async Task ShouldInjectScriptAtCorrectLocation(string filename, string injected, int injectionPosition)
         {
             // Given
             TestServer server = GetServer();
@@ -29,14 +29,21 @@ public async Task InjectScriptWhenAppropriate(string filename, bool inject)
 
             // Then
             response.StatusCode.ShouldBe(System.Net.HttpStatusCode.OK);
-            if (inject)
-            {
-                body.ShouldContain("<script type=\"text/javascript\" src=\"/livereload.js\"></script></body>");
-            }
-            else
-            {
-                body.ShouldBe(AssemblyHelper.ReadEmbeddedWebFile(filename));
-            }
+            body.LastIndexOf(injected).ShouldBe(injectionPosition);
+        }
+
+        [Test]
+        public async Task ShouldNotInjectNonHtmlContent()
+        {
+            // Given
+            TestServer server = GetServer();
+
+            // When
+            HttpResponseMessage response = await server.CreateRequest("NonHtmlDocument.css").GetAsync();
+            string body = await response.Content.ReadAsStringAsync();
+
+            // Then
+            body.ShouldBe(AssemblyHelper.ReadEmbeddedWebFile("NonHtmlDocument.css"));
         }
 
         private TestServer GetServer() => new TestServer(

tests/Statiq.Web.Hosting.Tests/Statiq.Web.Hosting.Tests.csproj

@@ -19,7 +19,8 @@
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="wwwroot\BasicHtmlDocument.html" />
-    <EmbeddedResource Include="wwwroot\BasicHtmlDocumentNoBodyEnd.html" />
+    <EmbeddedResource Include="wwwroot\BasicHtmlDocumentNoBody.html" />
+    <EmbeddedResource Include="wwwroot\BasicHtmlDocumentNoHtml.html" />
     <EmbeddedResource Include="wwwroot\NonHtmlDocument.css" />
   </ItemGroup>
 

tests/Statiq.Web.Hosting.Tests/wwwroot/BasicHtmlDocumentNoBodyEnd.html → tests/Statiq.Web.Hosting.Tests/wwwroot/BasicHtmlDocumentNoBody.html

@@ -5,4 +5,5 @@
     <meta charset="utf-8"/>
     <title></title>
 </head>
-<body>
+foo
+</html>

tests/Statiq.Web.Hosting.Tests/wwwroot/BasicHtmlDocumentNoHtml.html

@@ -0,0 +1,7 @@
+<!DOCTYPE html>
+
+<head>
+    <meta charset="utf-8"/>
+    <title></title>
+</head>
+foo