add support for image/avif

CHANGELOG.md

@@ -3,6 +3,7 @@
 * Update video/mp4 mimeType lookup by header bytes.
 * Add image/heic mimeType lookup by header bytes.
 * Add image/heif mimeType lookup by header bytes.
+* Add image/avif mimeType lookup by header bytes.
 * Add m4b mimeType lookup by extension.
 * Add `text/markdown` mimeType lookup by extension.
 * Require Dart 3.0.0.

lib/src/magic_number.dart

@@ -275,6 +275,38 @@ const List<MagicNumber> initialMagicNumbers = [
   ]),
   MagicNumber('model/gltf-binary', [0x46, 0x54, 0x6C, 0x67]),
 
+  /// AVIF format identification
+  /// -> 4 bytes indicating the ftyp box length.
+  /// -> 4 bytes have the ASCII characters 'f' 't' 'y' 'p'.
+  /// -> 4 bytes have the ASCII characters 'a' 'v' 'i' 'f'.
+  MagicNumber('image/avif', [
+    0x00,
+    0x00,
+    0x00,
+    0x00,
+    0x66,
+    0x74,
+    0x79,
+    0x70,
+    0x61,
+    0x76,
+    0x69,
+    0x66
+  ], mask: [
+    0x00,
+    0x00,
+    0x00,
+    0x00,
+    0xFF,
+    0xFF,
+    0xFF,
+    0xFF,
+    0xFF,
+    0xFF,
+    0xFF,
+    0xFF
+  ]),
+
   /// The WebP file format is based on the RIFF document format.
   /// -> 4 bytes have the ASCII characters 'R' 'I' 'F' 'F'.
   /// -> 4 bytes indicating the size of the file

test/mime_type_test.dart

@@ -75,6 +75,20 @@ void main() {
         0x1A,
         0x0A
       ]);
+      _expectMimeType('file.avif', 'image/avif', headerBytes: [
+        0x00,
+        0x00,
+        0x00,
+        0x20,
+        0x66,
+        0x74,
+        0x79,
+        0x70,
+        0x61,
+        0x76,
+        0x69,
+        0x66
+      ]);
       _expectMimeType('file.gif', 'image/jpeg', headerBytes: [
         0xFF,
         0xD8,