diff --git a/tests/ImageSharp.Tests/Image/ImageDiscoverMimeType.cs b/tests/ImageSharp.Tests/Image/ImageDiscoverMimeType.cs
new file mode 100644
index 000000000..80414662b
--- /dev/null
+++ b/tests/ImageSharp.Tests/Image/ImageDiscoverMimeType.cs
@@ -0,0 +1,107 @@
+// <copyright file="PixelAccessorTests.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageSharp.Tests
+{
+    using System;
+    using System.IO;
+
+    using ImageSharp.Formats;
+    using ImageSharp.IO;
+    using ImageSharp.PixelFormats;
+    using Moq;
+    using Xunit;
+
+    /// <summary>
+    /// Tests the <see cref="Image"/> class.
+    /// </summary>
+    public class DiscoverMimeTypeTests
+    {
+        private readonly Mock<IFileSystem> fileSystem;
+        private readonly string FilePath;
+        private readonly Mock<IMimeTypeDetector> localMimeTypeDetector;
+
+        public Configuration LocalConfiguration { get; private set; }
+        public byte[] Marker { get; private set; }
+        public MemoryStream DataStream { get; private set; }
+        public byte[] DecodedData { get; private set; }
+        private const string localMimeType = "image/local";
+
+        public DiscoverMimeTypeTests()
+        {
+            this.localMimeTypeDetector = new Mock<IMimeTypeDetector>();
+            this.localMimeTypeDetector.Setup(x => x.HeaderSize).Returns(1);
+            this.localMimeTypeDetector.Setup(x => x.DetectMimeType(It.IsAny<Span<byte>>())).Returns(localMimeType);
+
+            this.fileSystem = new Mock<IFileSystem>();
+
+            this.LocalConfiguration = new Configuration()
+            {
+                FileSystem = this.fileSystem.Object
+            };
+            this.LocalConfiguration.AddMimeTypeDetector(this.localMimeTypeDetector.Object);
+
+            TestFormat.RegisterGloablTestFormat();
+            this.Marker = Guid.NewGuid().ToByteArray();
+            this.DataStream = TestFormat.GlobalTestFormat.CreateStream(this.Marker);
+
+            this.FilePath = Guid.NewGuid().ToString();
+            this.fileSystem.Setup(x => x.OpenRead(this.FilePath)).Returns(this.DataStream);
+
+            TestFileSystem.RegisterGloablTestFormat();
+            TestFileSystem.Global.AddFile(this.FilePath, this.DataStream);
+        }
+
+        [Fact]
+        public void DiscoverMimeTypeByteArray()
+        {
+            var type = Image.DiscoverMimeType(DataStream.ToArray());
+            Assert.Equal(TestFormat.GlobalTestFormat.MimeType, type);
+        }
+
+        [Fact]
+        public void DiscoverMimeTypeByteArray_WithConfig()
+        {
+            var type = Image.DiscoverMimeType(this.LocalConfiguration, DataStream.ToArray());
+            Assert.Equal(localMimeType, type);
+        }
+
+        [Fact]
+        public void DiscoverMimeTypeFile()
+        {
+            var type = Image.DiscoverMimeType(this.FilePath);
+            Assert.Equal(TestFormat.GlobalTestFormat.MimeType, type);
+        }
+
+        [Fact]
+        public void DiscoverMimeTypeFilePath_WithConfig()
+        {
+            var type = Image.DiscoverMimeType(this.LocalConfiguration, FilePath);
+            Assert.Equal(localMimeType, type);
+        }
+
+
+        [Fact]
+        public void DiscoverMimeTypeStream()
+        {
+            var type = Image.DiscoverMimeType(this.DataStream);
+            Assert.Equal(TestFormat.GlobalTestFormat.MimeType, type);
+        }
+
+        [Fact]
+        public void DiscoverMimeTypeFileStream_WithConfig()
+        {
+            var type = Image.DiscoverMimeType(this.LocalConfiguration, DataStream);
+            Assert.Equal(localMimeType, type);
+        }
+
+        [Fact]
+        public void DiscoverMimeTypeNoDetectorsRegisterdShouldReturnNull()
+        {
+            var type = Image.DiscoverMimeType(new Configuration(), DataStream);
+            Assert.Null(type);
+        }
+    }
+}