Verify ContentType of uploaded images

tests/Jellyfin.Api.Tests/Controllers/ImageControllerTests.cs

@@ -0,0 +1,36 @@
+using System;
+using Jellyfin.Api.Controllers;
+using Xunit;
+
+namespace Jellyfin.Api.Tests.Controllers;
+
+public static class ImageControllerTests
+{
+    [Theory]
+    [InlineData("image/apng", ".apng")]
+    [InlineData("image/avif", ".avif")]
+    [InlineData("image/bmp", ".bmp")]
+    [InlineData("image/gif", ".gif")]
+    [InlineData("image/x-icon", ".ico")]
+    [InlineData("image/jpeg", ".jpg")]
+    [InlineData("image/png", ".png")]
+    [InlineData("image/png; charset=utf-8", ".png")]
+    [InlineData("image/svg+xml", ".svg")]
+    [InlineData("image/tiff", ".tiff")]
+    [InlineData("image/webp", ".webp")]
+    public static void TryGetImageExtensionFromContentType_Valid_True(string contentType, string extension)
+    {
+        Assert.True(ImageController.TryGetImageExtensionFromContentType(contentType, out var ex));
+        Assert.Equal(extension, ex);
+    }
+
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("text/html")]
+    public static void TryGetImageExtensionFromContentType_InValid_False(string contentType)
+    {
+        Assert.False(ImageController.TryGetImageExtensionFromContentType(contentType, out var ex));
+        Assert.Null(ex);
+    }
+}