Merge pull request #202 from SixLabors/js/format-utils-api

Fix method signature

src/ImageSharp.Web.Providers.Azure/Providers/AzureBlobStorageImageProvider.cs

@@ -127,7 +127,7 @@ public async Task<IImageResolver> GetAsync(HttpContext context)
 
         /// <inheritdoc/>
         public bool IsValidRequest(HttpContext context)
-            => this.formatUtilities.GetExtensionFromUri(context.Request.GetDisplayUrl()) != null;
+            => this.formatUtilities.TryGetExtensionFromUri(context.Request.GetDisplayUrl(), out _);
 
         private bool IsMatch(HttpContext context)
         {

src/ImageSharp.Web/FormatUtilities.cs

@@ -47,11 +47,18 @@ public FormatUtilities(IOptions<ImageSharpMiddlewareOptions> options)
         /// Gets the file extension for the given image uri.
         /// </summary>
         /// <param name="uri">The full request uri.</param>
-        /// <returns>The <see cref="string" />.</returns>
+        /// <param name="extension">
+        /// When this method returns, contains the file extension for the image source,
+        /// if the path exists; otherwise, the default value for the type of the path parameter.
+        /// This parameter is passed uninitialized.
+        /// </param>
+        /// <returns>
+        /// <see langword="true" /> if the uri contains an extension; otherwise, <see langword="false" />.
+        /// </returns>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public string GetExtensionFromUri(string uri)
+        public bool TryGetExtensionFromUri(string uri, out string extension)
         {
-            // TODO: This method should follow TryGet pattern. Fix for V2.
+            extension = null;
             int query = uri.IndexOf('?');
             ReadOnlySpan<char> path;
 
@@ -62,15 +69,16 @@ public string GetExtensionFromUri(string uri)
                 {
                     // We have a query but is it a valid one?
                     ReadOnlySpan<char> extSpan = ext[0].AsSpan();
-                    foreach (string extension in this.extensions)
+                    foreach (string e in this.extensions)
                     {
-                        if (extSpan.Equals(extension, StringComparison.OrdinalIgnoreCase))
+                        if (extSpan.Equals(e, StringComparison.OrdinalIgnoreCase))
                         {
-                            return extension;
+                            extension = e;
+                            return true;
                         }
                     }
 
-                    return null;
+                    return false;
                 }
 
                 path = uri.AsSpan(0, query);
@@ -85,16 +93,17 @@ public string GetExtensionFromUri(string uri)
             {
                 ReadOnlySpan<char> pathExtension = path.Slice(extensionIndex + 1);
 
-                foreach (string extension in this.extensions)
+                foreach (string e in this.extensions)
                 {
-                    if (pathExtension.Equals(extension, StringComparison.OrdinalIgnoreCase))
+                    if (pathExtension.Equals(e, StringComparison.OrdinalIgnoreCase))
                     {
-                        return extension;
+                        extension = e;
+                        return true;
                     }
                 }
             }
 
-            return null;
+            return false;
         }
 
         /// <summary>

src/ImageSharp.Web/Providers/PhysicalFileSystemProvider.cs

@@ -53,7 +53,8 @@ public PhysicalFileSystemProvider(
         public Func<HttpContext, bool> Match { get; set; } = _ => true;
 
         /// <inheritdoc/>
-        public bool IsValidRequest(HttpContext context) => this.formatUtilities.GetExtensionFromUri(context.Request.GetDisplayUrl()) != null;
+        public bool IsValidRequest(HttpContext context)
+            => this.formatUtilities.TryGetExtensionFromUri(context.Request.GetDisplayUrl(), out _);
 
         /// <inheritdoc/>
         public Task<IImageResolver> GetAsync(HttpContext context)

tests/ImageSharp.Web.Tests/Helpers/FormatUtilitiesTests.cs

@@ -21,35 +21,38 @@ public class FormatUtilitiesTests
         public void GetExtensionShouldMatchDefaultExtensions(string expected, string ext)
         {
             string uri = $"http://www.example.org/some/path/to/image.{ext}?width=300";
-            Assert.Equal(expected, FormatUtilities.GetExtensionFromUri(uri));
+            FormatUtilities.TryGetExtensionFromUri(uri, out string actual);
+            Assert.Equal(expected, actual);
         }
 
         [Fact]
         public void GetExtensionShouldNotMatchExtensionWithoutDotPrefix()
         {
             const string uri = "http://www.example.org/some/path/to/bmpimage";
-            Assert.Null(FormatUtilities.GetExtensionFromUri(uri));
+            Assert.False(FormatUtilities.TryGetExtensionFromUri(uri, out _));
         }
 
         [Fact]
         public void GetExtensionShouldIgnoreQueryStringWithoutFormatParamter()
         {
             const string uri = "http://www.example.org/some/path/to/image.bmp?width=300&foo=.png";
-            Assert.Equal("bmp", FormatUtilities.GetExtensionFromUri(uri));
+            FormatUtilities.TryGetExtensionFromUri(uri, out string actual);
+            Assert.Equal("bmp", actual);
         }
 
         [Fact]
         public void GetExtensionShouldAcknowledgeQueryStringFormatParameter()
         {
             const string uri = "http://www.example.org/some/path/to/image.bmp?width=300&format=png";
-            Assert.Equal("png", FormatUtilities.GetExtensionFromUri(uri));
+            FormatUtilities.TryGetExtensionFromUri(uri, out string actual);
+            Assert.Equal("png", actual);
         }
 
         [Fact]
         public void GetExtensionShouldRejectInvalidQueryStringFormatParameter()
         {
             const string uri = "http://www.example.org/some/path/to/image.bmp?width=300&format=invalid";
-            Assert.Null(FormatUtilities.GetExtensionFromUri(uri));
+            Assert.False(FormatUtilities.TryGetExtensionFromUri(uri, out _));
         }
     }
 }