From 9355522ea32d2e6a069b657680949fcb2533c9b9 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Thu, 5 Jan 2023 18:44:08 +0100
Subject: [PATCH 01/38] initial code from pr !15

---
 pkgs/mime/README.md                | 19 ++++++++++++++
 pkgs/mime/lib/mime.dart            |  1 +
 pkgs/mime/lib/src/extension.dart   | 33 ++++++++++++++++++++++++
 pkgs/mime/test/extension_test.dart | 41 ++++++++++++++++++++++++++++++
 4 files changed, 94 insertions(+)
 create mode 100644 pkgs/mime/lib/src/extension.dart
 create mode 100644 pkgs/mime/test/extension_test.dart

diff --git a/pkgs/mime/README.md b/pkgs/mime/README.md
index 8a814150c..eb4ab2ce4 100644
--- a/pkgs/mime/README.md
+++ b/pkgs/mime/README.md
@@ -57,3 +57,22 @@ request
     .map((part) => part.fold(0, (p, d) => p + d))
     .listen((length) => print('Part with length $length'));
 ```
+
+## Determining file extension by MIME type
+
+The top level function `lookupExtension` can be used to determine the
+file extension of a given MIME type.
+
+```dart
+print(lookupExtension('text/html'));  // Will print html
+print(lookupExtension('image/jpeg'));  // Will print jpg
+print(lookupExtension('application/pdf'));  // Will print pdf
+```
+
+You can override the default MIME type-extension mapping using
+`addMimeType`:
+
+```dart
+addMimeType('image/jpeg', 'jpeg');
+print(lookupExtension('image/jpeg'));  // Will print jpeg
+```
diff --git a/pkgs/mime/lib/mime.dart b/pkgs/mime/lib/mime.dart
index f2c446403..cb450981f 100644
--- a/pkgs/mime/lib/mime.dart
+++ b/pkgs/mime/lib/mime.dart
@@ -9,6 +9,7 @@
 /// [Internet media type](http://en.wikipedia.org/wiki/Internet_media_type).
 library;
 
+export 'src/extension.dart';
 export 'src/mime_multipart_transformer.dart';
 export 'src/mime_shared.dart';
 export 'src/mime_type.dart';
diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
new file mode 100644
index 000000000..e27948dcf
--- /dev/null
+++ b/pkgs/mime/lib/src/extension.dart
@@ -0,0 +1,33 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'default_extension_map.dart';
+
+/// Add an override for common extensions since different extensions may map
+/// to the same MIME type.
+final Map<String, String> _preferredExtensionsMap = <String, String>{
+  'application/vnd.ms-excel': 'xls',
+  'image/jpeg': 'jpg',
+  'text/x-c': 'c'
+};
+
+/// Lookup file extension by a given MIME type.
+/// If no extension is found, `null` is returned.
+String lookupExtension(String mimeType) {
+  if (_preferredExtensionsMap.containsKey(mimeType)) {
+    return _preferredExtensionsMap[mimeType];
+  }
+  String extension;
+  defaultExtensionMap.forEach((String ext, String test) {
+    if (mimeType.toLowerCase() == test) {
+      extension = ext;
+    }
+  });
+  return extension;
+}
+
+/// Allow for a user-specified MIME type-extension map that overrides the default.
+void addMimeType(String mimeType, String extension) {
+  _preferredExtensionsMap[mimeType] = extension;
+}
\ No newline at end of file
diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
new file mode 100644
index 000000000..c5e1b495e
--- /dev/null
+++ b/pkgs/mime/test/extension_test.dart
@@ -0,0 +1,41 @@
+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:test/test.dart';
+import 'package:mime/mime.dart';
+
+void main() {
+  group('lookup-mime-type', () {
+    test('valid-mime-type', () {
+      expect(lookupExtension('application/dart'), equals('dart'));
+      expect(lookupExtension('application/javascript'), equals('js'));
+      expect(lookupExtension('application/pdf'), equals('pdf'));
+      expect(lookupExtension('application/vnd.ms-excel'), equals('xls'));
+      expect(lookupExtension('application/xhtml+xml'), equals('xhtml'));
+      expect(lookupExtension('image/jpeg'), equals('jpg'));
+      expect(lookupExtension('image/png'), equals('png'));
+      expect(lookupExtension('text/css'), equals('css'));
+      expect(lookupExtension('text/html'), equals('html'));
+      expect(lookupExtension('text/plain'), equals('txt'));
+      expect(lookupExtension('text/x-c'), equals('c'));
+    });
+
+    test('invalid-mime-type', () {
+      expect(lookupExtension('invalid-content-type'), isNull);
+      expect(lookupExtension('invalid/content-type'), isNull);
+    });
+  });
+
+  group('add-mime-type', () {
+    test('new-mime-type', () {
+      addMimeType('custom/type', 'ct');
+      expect(lookupExtension('custom/type'), equals('ct'));
+    });
+
+    test('overridden-mime-type', () {
+      addMimeType('image/jpeg', 'jpeg');
+      expect(lookupExtension('image/jpeg'), equals('jpeg'));
+    });
+  });
+}
\ No newline at end of file

From e7f328eb09fecb47f6b4157c328b39cc8b64c504 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Thu, 5 Jan 2023 18:47:40 +0100
Subject: [PATCH 02/38] update copyright year

---
 pkgs/mime/test/extension_test.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index c5e1b495e..51432e8e7 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -1,4 +1,4 @@
-// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 

From 7eb72c38973812bc0ada281297080ac49a9fa470 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Fri, 6 Jan 2023 17:13:06 +0100
Subject: [PATCH 03/38] improve lookup: case-insensitive and use
 firstWhereOrNull instead of for loop

---
 pkgs/mime/lib/src/extension.dart | 25 ++++++++++++-------------
 pkgs/mime/pubspec.yaml           |  3 +++
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index e27948dcf..70e37a5f5 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -2,6 +2,8 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+import 'package:collection/collection.dart';
+
 import 'default_extension_map.dart';
 
 /// Add an override for common extensions since different extensions may map
@@ -14,20 +16,17 @@ final Map<String, String> _preferredExtensionsMap = <String, String>{
 
 /// Lookup file extension by a given MIME type.
 /// If no extension is found, `null` is returned.
-String lookupExtension(String mimeType) {
-  if (_preferredExtensionsMap.containsKey(mimeType)) {
-    return _preferredExtensionsMap[mimeType];
+String? lookupExtension(String mimeType) {
+  final mimeTypeLC = mimeType.toLowerCase();
+  if (_preferredExtensionsMap.containsKey(mimeTypeLC)) {
+    return _preferredExtensionsMap[mimeTypeLC]!;
   }
-  String extension;
-  defaultExtensionMap.forEach((String ext, String test) {
-    if (mimeType.toLowerCase() == test) {
-      extension = ext;
-    }
-  });
-  return extension;
+  return defaultExtensionMap.entries
+      .firstWhereOrNull((entry) => entry.value == mimeTypeLC)?.key;
 }
 
-/// Allow for a user-specified MIME type-extension map that overrides the default.
+/// Allow for a user-specified MIME type-extension mapping that overrides the
+/// default.
 void addMimeType(String mimeType, String extension) {
-  _preferredExtensionsMap[mimeType] = extension;
-}
\ No newline at end of file
+  _preferredExtensionsMap[mimeType.toLowerCase()] = extension.toLowerCase();
+}
diff --git a/pkgs/mime/pubspec.yaml b/pkgs/mime/pubspec.yaml
index 8d3c49823..0dec004e1 100644
--- a/pkgs/mime/pubspec.yaml
+++ b/pkgs/mime/pubspec.yaml
@@ -13,6 +13,9 @@ topics:
 environment:
   sdk: ^3.2.0
 
+dependencies:
+  collection: ^1.17.0
+
 dev_dependencies:
   dart_flutter_team_lints: ^3.0.0
   test: ^1.16.0

From 80079be5dc826cdc5ef1a902bb607a37e831c81c Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Fri, 6 Jan 2023 17:13:33 +0100
Subject: [PATCH 04/38] tests cleanup

---
 pkgs/mime/test/extension_test.dart | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index 51432e8e7..f4ad5b347 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -2,28 +2,31 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'package:test/test.dart';
 import 'package:mime/mime.dart';
+import 'package:test/test.dart';
 
 void main() {
-  group('lookup-mime-type', () {
+  group('global-lookup-mime-type', () {
     test('valid-mime-type', () {
-      expect(lookupExtension('application/dart'), equals('dart'));
-      expect(lookupExtension('application/javascript'), equals('js'));
+      expect(lookupExtension('text/x-dart'), equals('dart'));
+      expect(lookupExtension('text/javascript'), equals('js'));
       expect(lookupExtension('application/pdf'), equals('pdf'));
       expect(lookupExtension('application/vnd.ms-excel'), equals('xls'));
-      expect(lookupExtension('application/xhtml+xml'), equals('xhtml'));
+      expect(lookupExtension('application/xhtml+xml'), equals('xht'));
       expect(lookupExtension('image/jpeg'), equals('jpg'));
       expect(lookupExtension('image/png'), equals('png'));
       expect(lookupExtension('text/css'), equals('css'));
-      expect(lookupExtension('text/html'), equals('html'));
-      expect(lookupExtension('text/plain'), equals('txt'));
+      expect(lookupExtension('text/html'), equals('htm'));
+      // expect(lookupExtension('text/plain'), equals('txt'));
       expect(lookupExtension('text/x-c'), equals('c'));
     });
 
     test('invalid-mime-type', () {
-      expect(lookupExtension('invalid-content-type'), isNull);
-      expect(lookupExtension('invalid/content-type'), isNull);
+      expect(lookupExtension('invalid-mime-type'), isNull);
+    });
+
+    test('unknown-mime-type', () {
+      expect(lookupExtension('application/to-be-invented'), isNull);
     });
   });
 

From d3ce7aea5ac116a5ea905d58d78bacb1904b5620 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Fri, 6 Jan 2023 17:16:14 +0100
Subject: [PATCH 05/38] check baseline

---
 pkgs/mime/test/extension_test.dart | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index f4ad5b347..f096f1b54 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -32,11 +32,13 @@ void main() {
 
   group('add-mime-type', () {
     test('new-mime-type', () {
+      expect(lookupExtension('custom/type'), isNull);
       addMimeType('custom/type', 'ct');
       expect(lookupExtension('custom/type'), equals('ct'));
     });
 
     test('overridden-mime-type', () {
+      expect(lookupExtension('image/jpeg'), equals('jpg'));
       addMimeType('image/jpeg', 'jpeg');
       expect(lookupExtension('image/jpeg'), equals('jpeg'));
     });

From 29050ff8830e977cb4242b89e9fbddcaaf3986a5 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Fri, 6 Jan 2023 17:47:59 +0100
Subject: [PATCH 06/38] test to check whether each mimetype with multiple
 extensions has a preferred extension defined

---
 pkgs/mime/lib/src/extension.dart   |  3 +++
 pkgs/mime/test/extension_test.dart | 22 +++++++++++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 70e37a5f5..fdc34b2ec 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -30,3 +30,6 @@ String? lookupExtension(String mimeType) {
 void addMimeType(String mimeType, String extension) {
   _preferredExtensionsMap[mimeType.toLowerCase()] = extension.toLowerCase();
 }
+
+bool hasPreferredExtension(String mimeType) =>
+    _preferredExtensionsMap.containsKey(mimeType.toLowerCase());
diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index f096f1b54..06106d267 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:mime/mime.dart';
+import 'package:mime/src/default_extension_map.dart';
 import 'package:test/test.dart';
 
 void main() {
@@ -42,5 +43,24 @@ void main() {
       addMimeType('image/jpeg', 'jpeg');
       expect(lookupExtension('image/jpeg'), equals('jpeg'));
     });
+
+    test('check-preferred-present-for-non-unique', () {
+      final mimeTypeToExtMap = <String, List<String>>{};
+      for (var entry in defaultExtensionMap.entries) {
+        final extensions = mimeTypeToExtMap.putIfAbsent(entry.value, () => []);
+        extensions.add(entry.key);
+      }
+      final mimeTypesWithMultipleExtensions = Map.fromEntries(mimeTypeToExtMap
+          .entries
+          .where((element) => element.value.length > 1));
+      for (var mimeType in mimeTypesWithMultipleExtensions.keys) {
+        expect(
+          hasPreferredExtension(mimeType),
+          isTrue,
+          reason: 'mimeType $mimeType with multiple extension, '
+              'does not have preferred extension defined',
+        );
+      }
+    });
   });
-}
\ No newline at end of file
+}

From 84f3bd8f83636e79e7f11f47e7d96058b729ee78 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Fri, 6 Jan 2023 17:48:08 +0100
Subject: [PATCH 07/38] reformat

---
 pkgs/mime/lib/src/extension.dart | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index fdc34b2ec..765c61093 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -22,7 +22,8 @@ String? lookupExtension(String mimeType) {
     return _preferredExtensionsMap[mimeTypeLC]!;
   }
   return defaultExtensionMap.entries
-      .firstWhereOrNull((entry) => entry.value == mimeTypeLC)?.key;
+      .firstWhereOrNull((entry) => entry.value == mimeTypeLC)
+      ?.key;
 }
 
 /// Allow for a user-specified MIME type-extension mapping that overrides the

From c27fa377aba51394578559cc435e31193cd705f3 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Fri, 6 Jan 2023 19:05:56 +0100
Subject: [PATCH 08/38] apparently, the function already existed :roll-eyes:
 but the preferred extension not. for backwards compatibility: add
 `extensionFromMimeOrNull`, and add an `orElse` param for `extensionFromMime`
 as the standard behavior results in creating an invalid filename.

---
 pkgs/mime/lib/src/extension.dart   | 10 +++++--
 pkgs/mime/lib/src/mime_type.dart   | 14 ---------
 pkgs/mime/test/extension_test.dart | 46 +++++++++++++++++++-----------
 3 files changed, 37 insertions(+), 33 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 765c61093..4a356a17d 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -14,9 +14,12 @@ final Map<String, String> _preferredExtensionsMap = <String, String>{
   'text/x-c': 'c'
 };
 
-/// Lookup file extension by a given MIME type.
+/// Lookup file extension for a given MIME type.
+///
+/// If there are multiple extensions for [mimeType], return preferred extension
+/// if defined, or the first occurrence in the map.
 /// If no extension is found, `null` is returned.
-String? lookupExtension(String mimeType) {
+String? extensionFromMimeOrNull(String mimeType) {
   final mimeTypeLC = mimeType.toLowerCase();
   if (_preferredExtensionsMap.containsKey(mimeTypeLC)) {
     return _preferredExtensionsMap[mimeTypeLC]!;
@@ -26,6 +29,9 @@ String? lookupExtension(String mimeType) {
       ?.key;
 }
 
+String extensionFromMime(String mimeType, {String? orElse}) =>
+    extensionFromMimeOrNull(mimeType) ?? orElse ?? mimeType;
+
 /// Allow for a user-specified MIME type-extension mapping that overrides the
 /// default.
 void addMimeType(String mimeType, String extension) {
diff --git a/pkgs/mime/lib/src/mime_type.dart b/pkgs/mime/lib/src/mime_type.dart
index 03121c97b..9cf9194a1 100644
--- a/pkgs/mime/lib/src/mime_type.dart
+++ b/pkgs/mime/lib/src/mime_type.dart
@@ -23,20 +23,6 @@ int get defaultMagicNumbersMaxLength => _globalResolver.magicNumbersMaxLength;
 String? lookupMimeType(String path, {List<int>? headerBytes}) =>
     _globalResolver.lookup(path, headerBytes: headerBytes);
 
-/// Returns the extension for the given MIME type.
-///
-/// If there are multiple extensions for [mime], return the first occurrence in
-/// the map. If there are no extensions for [mime], return [mime].
-String extensionFromMime(String mime) {
-  mime = mime.toLowerCase();
-  for (final entry in defaultExtensionMap.entries) {
-    if (defaultExtensionMap[entry.key] == mime) {
-      return entry.key;
-    }
-  }
-  return mime;
-}
-
 /// MIME-type resolver class, used to customize the lookup of mime-types.
 class MimeTypeResolver {
   final Map<String, String> _extensionMap = {};
diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index 06106d267..62c084fc1 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -9,39 +9,51 @@ import 'package:test/test.dart';
 void main() {
   group('global-lookup-mime-type', () {
     test('valid-mime-type', () {
-      expect(lookupExtension('text/x-dart'), equals('dart'));
-      expect(lookupExtension('text/javascript'), equals('js'));
-      expect(lookupExtension('application/pdf'), equals('pdf'));
-      expect(lookupExtension('application/vnd.ms-excel'), equals('xls'));
-      expect(lookupExtension('application/xhtml+xml'), equals('xht'));
-      expect(lookupExtension('image/jpeg'), equals('jpg'));
-      expect(lookupExtension('image/png'), equals('png'));
-      expect(lookupExtension('text/css'), equals('css'));
-      expect(lookupExtension('text/html'), equals('htm'));
-      // expect(lookupExtension('text/plain'), equals('txt'));
-      expect(lookupExtension('text/x-c'), equals('c'));
+      expect(extensionFromMime('text/x-dart'), equals('dart'));
+      expect(extensionFromMime('text/javascript'), equals('js'));
+      expect(extensionFromMime('application/pdf'), equals('pdf'));
+      expect(extensionFromMime('application/vnd.ms-excel'), equals('xls'));
+      expect(extensionFromMime('application/xhtml+xml'), equals('xht'));
+      expect(extensionFromMime('image/jpeg'), equals('jpg'));
+      expect(extensionFromMime('image/png'), equals('png'));
+      expect(extensionFromMime('text/css'), equals('css'));
+      expect(extensionFromMime('text/html'), equals('htm'));
+      // expect(extensionFromMime('text/plain'), equals('txt'));
+      expect(extensionFromMime('text/x-c'), equals('c'));
     });
 
     test('invalid-mime-type', () {
-      expect(lookupExtension('invalid-mime-type'), isNull);
+      expect(extensionFromMime('invalid-mime-type'), 'invalid-mime-type');
+      expect(extensionFromMime('invalid/mime/type'), 'invalid/mime/type');
+
+      expect(
+          extensionFromMime('invalid-mime-type', orElse: 'invalid'), 'invalid');
+      expect(
+          extensionFromMime('invalid/mime/type', orElse: 'invalid'), 'invalid');
+
+      expect(extensionFromMimeOrNull('invalid-mime-type'), isNull);
+      expect(extensionFromMimeOrNull('invalid/mime/type'), isNull);
     });
 
     test('unknown-mime-type', () {
-      expect(lookupExtension('application/to-be-invented'), isNull);
+      expect(extensionFromMime('application/to-be-invented'),
+          'application/to-be-invented');
+
+      expect(extensionFromMimeOrNull('application/to-be-invented'), isNull);
     });
   });
 
   group('add-mime-type', () {
     test('new-mime-type', () {
-      expect(lookupExtension('custom/type'), isNull);
+      expect(extensionFromMimeOrNull('custom/type'), isNull);
       addMimeType('custom/type', 'ct');
-      expect(lookupExtension('custom/type'), equals('ct'));
+      expect(extensionFromMime('custom/type'), equals('ct'));
     });
 
     test('overridden-mime-type', () {
-      expect(lookupExtension('image/jpeg'), equals('jpg'));
+      expect(extensionFromMime('image/jpeg'), equals('jpg'));
       addMimeType('image/jpeg', 'jpeg');
-      expect(lookupExtension('image/jpeg'), equals('jpeg'));
+      expect(extensionFromMime('image/jpeg'), equals('jpeg'));
     });
 
     test('check-preferred-present-for-non-unique', () {

From f2a62f7f57df1367728cd8b99f784a063685e672 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Fri, 6 Jan 2023 19:07:59 +0100
Subject: [PATCH 09/38] probably better not to enforce a preferred extension
 for mime types with multiple extensions. There are quite some, but most of
 them are legacy, and new mimetypes tend to map to 1 extension (no 3 chars
 limit anymore), so less useful in the future

---
 pkgs/mime/CONTRIBUTING.md          |  4 ++++
 pkgs/mime/lib/src/extension.dart   |  3 ---
 pkgs/mime/test/extension_test.dart | 20 --------------------
 3 files changed, 4 insertions(+), 23 deletions(-)

diff --git a/pkgs/mime/CONTRIBUTING.md b/pkgs/mime/CONTRIBUTING.md
index 6f5e0ea67..50a36a2d7 100644
--- a/pkgs/mime/CONTRIBUTING.md
+++ b/pkgs/mime/CONTRIBUTING.md
@@ -31,3 +31,7 @@ All files in the project must start with the following header.
 Contributions made by corporations are covered by a different agreement than the
 one above, the
 [Software Grant and Corporate Contributor License Agreement](https://developers.google.com/open-source/cla/corporate).
+
+### Adding an extension to an existing MIME type
+If a MIME type ends up with multiple extensions, it is recommended to define a 
+preferred extension in `_preferredExtensionsMap` in `extension.dart` 
\ No newline at end of file
diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 4a356a17d..04a80718d 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -37,6 +37,3 @@ String extensionFromMime(String mimeType, {String? orElse}) =>
 void addMimeType(String mimeType, String extension) {
   _preferredExtensionsMap[mimeType.toLowerCase()] = extension.toLowerCase();
 }
-
-bool hasPreferredExtension(String mimeType) =>
-    _preferredExtensionsMap.containsKey(mimeType.toLowerCase());
diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index 62c084fc1..0f6df2855 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -3,7 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:mime/mime.dart';
-import 'package:mime/src/default_extension_map.dart';
 import 'package:test/test.dart';
 
 void main() {
@@ -55,24 +54,5 @@ void main() {
       addMimeType('image/jpeg', 'jpeg');
       expect(extensionFromMime('image/jpeg'), equals('jpeg'));
     });
-
-    test('check-preferred-present-for-non-unique', () {
-      final mimeTypeToExtMap = <String, List<String>>{};
-      for (var entry in defaultExtensionMap.entries) {
-        final extensions = mimeTypeToExtMap.putIfAbsent(entry.value, () => []);
-        extensions.add(entry.key);
-      }
-      final mimeTypesWithMultipleExtensions = Map.fromEntries(mimeTypeToExtMap
-          .entries
-          .where((element) => element.value.length > 1));
-      for (var mimeType in mimeTypesWithMultipleExtensions.keys) {
-        expect(
-          hasPreferredExtension(mimeType),
-          isTrue,
-          reason: 'mimeType $mimeType with multiple extension, '
-              'does not have preferred extension defined',
-        );
-      }
-    });
   });
 }

From bdb76d3d52e5489df6d3e378ce8e038bad959a71 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Fri, 6 Jan 2023 19:08:49 +0100
Subject: [PATCH 10/38] added some preferred extensions for common file formats

---
 pkgs/mime/lib/src/extension.dart | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 04a80718d..c70afb14b 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -10,8 +10,19 @@ import 'default_extension_map.dart';
 /// to the same MIME type.
 final Map<String, String> _preferredExtensionsMap = <String, String>{
   'application/vnd.ms-excel': 'xls',
+  'application/vnd.ms-powerpoint': 'ppt',
   'image/jpeg': 'jpg',
-  'text/x-c': 'c'
+  'image/tiff': 'tif',
+  'image/svg+xml': 'svg',
+  'text/calendar': 'ics',
+  'text/javascript': 'js',
+  'text/plain': 'txt',
+  'text/sgml': 'sgml',
+  'text/x-pascal': 'pas',
+  'video/mp4': 'mp4',
+  'video/mpeg': 'mpg',
+  'video/quicktime': 'mov',
+  'video/x-matroska': 'mkv',
 };
 
 /// Lookup file extension for a given MIME type.

From 16f54d571c72d5bc8d77a41f20c182a5ac9ac704 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Fri, 6 Jan 2023 19:16:54 +0100
Subject: [PATCH 11/38] cleanup old tests

---
 pkgs/mime/test/extension_test.dart |  2 ++
 pkgs/mime/test/mime_type_test.dart | 17 -----------------
 2 files changed, 2 insertions(+), 17 deletions(-)

diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index 0f6df2855..a3d7f98f7 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -10,6 +10,8 @@ void main() {
     test('valid-mime-type', () {
       expect(extensionFromMime('text/x-dart'), equals('dart'));
       expect(extensionFromMime('text/javascript'), equals('js'));
+      expect(extensionFromMime('application/java-archive'), equals('jar'));
+      expect(extensionFromMime('application/json'), equals('json'));
       expect(extensionFromMime('application/pdf'), equals('pdf'));
       expect(extensionFromMime('application/vnd.ms-excel'), equals('xls'));
       expect(extensionFromMime('application/xhtml+xml'), equals('xht'));
diff --git a/pkgs/mime/test/mime_type_test.dart b/pkgs/mime/test/mime_type_test.dart
index f7388ff34..56efba88b 100644
--- a/pkgs/mime/test/mime_type_test.dart
+++ b/pkgs/mime/test/mime_type_test.dart
@@ -318,21 +318,4 @@ void main() {
     expect(initialMagicNumbersMaxLength, actualMaxBytes);
   });
 
-  group('extensionFromMime', () {
-    test('returns match for mime with single extension', () {
-      expect(extensionFromMime('application/json'), equals('json'));
-      expect(extensionFromMime('application/java-archive'), equals('jar'));
-    });
-
-    test('returns first match for mime with multiple extensions', () {
-      expect(extensionFromMime('text/html'), equals('htm'));
-      expect(extensionFromMime('application/x-cbr'), equals('cb7'));
-    });
-
-    test('returns inputted string for unrecognized mime', () {
-      expect(
-          extensionFromMime('unrecognized_mime'), equals('unrecognized_mime'));
-      expect(extensionFromMime('i/am/not/a/mime'), equals('i/am/not/a/mime'));
-    });
-  });
 }

From dccafc0ab26bc9d5a39f1db2aa67466fb87b179b Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Mon, 16 Jan 2023 15:16:02 +0100
Subject: [PATCH 12/38] test orElse param for unknown mime type

---
 pkgs/mime/test/extension_test.dart | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index a3d7f98f7..bed63b49a 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -40,6 +40,9 @@ void main() {
       expect(extensionFromMime('application/to-be-invented'),
           'application/to-be-invented');
 
+      expect(extensionFromMime('application/to-be-invented', orElse: 'unknown'),
+          'unknown');
+
       expect(extensionFromMimeOrNull('application/to-be-invented'), isNull);
     });
   });

From 59c6ec2891d85a04eb654960c0b3e952bd32eb33 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Mon, 16 Jan 2023 15:22:24 +0100
Subject: [PATCH 13/38] link to file

---
 pkgs/mime/CONTRIBUTING.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/mime/CONTRIBUTING.md b/pkgs/mime/CONTRIBUTING.md
index 50a36a2d7..cd7d82f0c 100644
--- a/pkgs/mime/CONTRIBUTING.md
+++ b/pkgs/mime/CONTRIBUTING.md
@@ -34,4 +34,4 @@ one above, the
 
 ### Adding an extension to an existing MIME type
 If a MIME type ends up with multiple extensions, it is recommended to define a 
-preferred extension in `_preferredExtensionsMap` in `extension.dart` 
\ No newline at end of file
+preferred extension in `_preferredExtensionsMap` in [extension.dart](lib/src/extension.dart). 
\ No newline at end of file

From 9e4b9d0c1155a43243341106901c6b14bd89df2d Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Mon, 16 Jan 2023 15:26:38 +0100
Subject: [PATCH 14/38] fix title to be more accurate

---
 pkgs/mime/CONTRIBUTING.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/mime/CONTRIBUTING.md b/pkgs/mime/CONTRIBUTING.md
index cd7d82f0c..bd079dd62 100644
--- a/pkgs/mime/CONTRIBUTING.md
+++ b/pkgs/mime/CONTRIBUTING.md
@@ -32,6 +32,6 @@ Contributions made by corporations are covered by a different agreement than the
 one above, the
 [Software Grant and Corporate Contributor License Agreement](https://developers.google.com/open-source/cla/corporate).
 
-### Adding an extension to an existing MIME type
+### Adding an extension / MIME type mapping
 If a MIME type ends up with multiple extensions, it is recommended to define a 
 preferred extension in `_preferredExtensionsMap` in [extension.dart](lib/src/extension.dart). 
\ No newline at end of file

From bc90ebd838d54445c285b1b4957a1f74a98acab7 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Mon, 16 Jan 2023 15:32:15 +0100
Subject: [PATCH 15/38] rename to existing function

---
 pkgs/mime/README.md | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pkgs/mime/README.md b/pkgs/mime/README.md
index eb4ab2ce4..18ecbb622 100644
--- a/pkgs/mime/README.md
+++ b/pkgs/mime/README.md
@@ -64,9 +64,9 @@ The top level function `lookupExtension` can be used to determine the
 file extension of a given MIME type.
 
 ```dart
-print(lookupExtension('text/html'));  // Will print html
-print(lookupExtension('image/jpeg'));  // Will print jpg
-print(lookupExtension('application/pdf'));  // Will print pdf
+print(extensionFromMime('text/html'));  // Will print html
+print(extensionFromMime('image/jpeg'));  // Will print jpg
+print(extensionFromMime('application/pdf'));  // Will print pdf
 ```
 
 You can override the default MIME type-extension mapping using
@@ -74,5 +74,5 @@ You can override the default MIME type-extension mapping using
 
 ```dart
 addMimeType('image/jpeg', 'jpeg');
-print(lookupExtension('image/jpeg'));  // Will print jpeg
+print(extensionFromMime('image/jpeg'));  // Will print jpeg
 ```

From cd5e5015aeaba8855208fd272044cf0f2236d3a5 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Mon, 16 Jan 2023 15:32:41 +0100
Subject: [PATCH 16/38] add standard behavior to make example more clear

---
 pkgs/mime/README.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pkgs/mime/README.md b/pkgs/mime/README.md
index 18ecbb622..1a1e44f55 100644
--- a/pkgs/mime/README.md
+++ b/pkgs/mime/README.md
@@ -73,6 +73,7 @@ You can override the default MIME type-extension mapping using
 `addMimeType`:
 
 ```dart
+print(extensionFromMime('image/jpeg'));  // Will print jpg
 addMimeType('image/jpeg', 'jpeg');
 print(extensionFromMime('image/jpeg'));  // Will print jpeg
 ```

From 557520ef0003002157d6e133051107a89311c777 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Mon, 16 Jan 2023 15:34:31 +0100
Subject: [PATCH 17/38] include text/plain mapping again

---
 pkgs/mime/test/extension_test.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index bed63b49a..7a22f0203 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -19,7 +19,7 @@ void main() {
       expect(extensionFromMime('image/png'), equals('png'));
       expect(extensionFromMime('text/css'), equals('css'));
       expect(extensionFromMime('text/html'), equals('htm'));
-      // expect(extensionFromMime('text/plain'), equals('txt'));
+      expect(extensionFromMime('text/plain'), equals('txt'));
       expect(extensionFromMime('text/x-c'), equals('c'));
     });
 

From 8c1f0a05e8e9beaba12a44bbc0c64953bdad591c Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Tue, 17 Jan 2023 10:31:44 +0100
Subject: [PATCH 18/38] remove collection dependency

---
 pkgs/mime/lib/src/extension.dart | 12 ++++++++++--
 pkgs/mime/pubspec.yaml           |  3 ---
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index c70afb14b..94e3f7da5 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -2,8 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import 'package:collection/collection.dart';
-
 import 'default_extension_map.dart';
 
 /// Add an override for common extensions since different extensions may map
@@ -48,3 +46,13 @@ String extensionFromMime(String mimeType, {String? orElse}) =>
 void addMimeType(String mimeType, String extension) {
   _preferredExtensionsMap[mimeType.toLowerCase()] = extension.toLowerCase();
 }
+
+extension _IterableExtension<T> on Iterable<T> {
+  /// The first element satisfying [test], or `null` if there are none.
+  T? firstWhereOrNull(bool Function(T element) test) {
+    for (var element in this) {
+      if (test(element)) return element;
+    }
+    return null;
+  }
+}
\ No newline at end of file
diff --git a/pkgs/mime/pubspec.yaml b/pkgs/mime/pubspec.yaml
index 0dec004e1..8d3c49823 100644
--- a/pkgs/mime/pubspec.yaml
+++ b/pkgs/mime/pubspec.yaml
@@ -13,9 +13,6 @@ topics:
 environment:
   sdk: ^3.2.0
 
-dependencies:
-  collection: ^1.17.0
-
 dev_dependencies:
   dart_flutter_team_lints: ^3.0.0
   test: ^1.16.0

From 07011650e1e22f7bfe3a6a8703b1511fbe351b15 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <178714+mx1up@users.noreply.github.com>
Date: Fri, 27 Jan 2023 14:08:23 +0100
Subject: [PATCH 19/38] lookupExtension has been renamed to existing
 extensionFromMime

---
 pkgs/mime/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/mime/README.md b/pkgs/mime/README.md
index 1a1e44f55..3bd4a482a 100644
--- a/pkgs/mime/README.md
+++ b/pkgs/mime/README.md
@@ -60,7 +60,7 @@ request
 
 ## Determining file extension by MIME type
 
-The top level function `lookupExtension` can be used to determine the
+The top level function `extensionFromMime` can be used to determine the
 file extension of a given MIME type.
 
 ```dart

From 7ad372340c6344cee3e865c4e4c7fe784f01e93a Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Wed, 13 Dec 2023 19:13:13 +0100
Subject: [PATCH 20/38] drop non-nullable extensionFromMime variant per review
 suggestion

---
 pkgs/mime/lib/src/extension.dart   |  5 +----
 pkgs/mime/test/extension_test.dart | 22 ++++------------------
 2 files changed, 5 insertions(+), 22 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 94e3f7da5..69a1bdcc9 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -28,7 +28,7 @@ final Map<String, String> _preferredExtensionsMap = <String, String>{
 /// If there are multiple extensions for [mimeType], return preferred extension
 /// if defined, or the first occurrence in the map.
 /// If no extension is found, `null` is returned.
-String? extensionFromMimeOrNull(String mimeType) {
+String? extensionFromMime(String mimeType) {
   final mimeTypeLC = mimeType.toLowerCase();
   if (_preferredExtensionsMap.containsKey(mimeTypeLC)) {
     return _preferredExtensionsMap[mimeTypeLC]!;
@@ -38,9 +38,6 @@ String? extensionFromMimeOrNull(String mimeType) {
       ?.key;
 }
 
-String extensionFromMime(String mimeType, {String? orElse}) =>
-    extensionFromMimeOrNull(mimeType) ?? orElse ?? mimeType;
-
 /// Allow for a user-specified MIME type-extension mapping that overrides the
 /// default.
 void addMimeType(String mimeType, String extension) {
diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index 7a22f0203..a57e9c648 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -24,32 +24,18 @@ void main() {
     });
 
     test('invalid-mime-type', () {
-      expect(extensionFromMime('invalid-mime-type'), 'invalid-mime-type');
-      expect(extensionFromMime('invalid/mime/type'), 'invalid/mime/type');
-
-      expect(
-          extensionFromMime('invalid-mime-type', orElse: 'invalid'), 'invalid');
-      expect(
-          extensionFromMime('invalid/mime/type', orElse: 'invalid'), 'invalid');
-
-      expect(extensionFromMimeOrNull('invalid-mime-type'), isNull);
-      expect(extensionFromMimeOrNull('invalid/mime/type'), isNull);
+      expect(extensionFromMime('invalid-mime-type'), isNull);
+      expect(extensionFromMime('invalid/mime/type'), isNull);
     });
 
     test('unknown-mime-type', () {
-      expect(extensionFromMime('application/to-be-invented'),
-          'application/to-be-invented');
-
-      expect(extensionFromMime('application/to-be-invented', orElse: 'unknown'),
-          'unknown');
-
-      expect(extensionFromMimeOrNull('application/to-be-invented'), isNull);
+      expect(extensionFromMime('application/to-be-invented'), isNull);
     });
   });
 
   group('add-mime-type', () {
     test('new-mime-type', () {
-      expect(extensionFromMimeOrNull('custom/type'), isNull);
+      expect(extensionFromMime('custom/type'), isNull);
       addMimeType('custom/type', 'ct');
       expect(extensionFromMime('custom/type'), equals('ct'));
     });

From 58ad484815dabc535275f19488873ea6d40da893 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Wed, 13 Dec 2023 19:34:09 +0100
Subject: [PATCH 21/38] doc update: try using noun phrase; don't refer to
 implementation details

---
 pkgs/mime/lib/src/extension.dart | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 69a1bdcc9..4344be9ae 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -23,10 +23,10 @@ final Map<String, String> _preferredExtensionsMap = <String, String>{
   'video/x-matroska': 'mkv',
 };
 
-/// Lookup file extension for a given MIME type.
+/// The extension for a given MIME type.
 ///
 /// If there are multiple extensions for [mimeType], return preferred extension
-/// if defined, or the first occurrence in the map.
+/// if defined, otherwise an extension chosen by the library.
 /// If no extension is found, `null` is returned.
 String? extensionFromMime(String mimeType) {
   final mimeTypeLC = mimeType.toLowerCase();

From eed2ba9b35abc9dee00e0c437b383fb6fccbc9b6 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Wed, 13 Dec 2023 19:37:19 +0100
Subject: [PATCH 22/38] don't use extension method

---
 pkgs/mime/lib/src/extension.dart | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 4344be9ae..b9160ed59 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -33,9 +33,11 @@ String? extensionFromMime(String mimeType) {
   if (_preferredExtensionsMap.containsKey(mimeTypeLC)) {
     return _preferredExtensionsMap[mimeTypeLC]!;
   }
-  return defaultExtensionMap.entries
-      .firstWhereOrNull((entry) => entry.value == mimeTypeLC)
-      ?.key;
+
+  for (final entry in defaultExtensionMap.entries) {
+    if (entry.value == mimeTypeLC) return entry.key;
+  }
+  return null;
 }
 
 /// Allow for a user-specified MIME type-extension mapping that overrides the
@@ -43,13 +45,3 @@ String? extensionFromMime(String mimeType) {
 void addMimeType(String mimeType, String extension) {
   _preferredExtensionsMap[mimeType.toLowerCase()] = extension.toLowerCase();
 }
-
-extension _IterableExtension<T> on Iterable<T> {
-  /// The first element satisfying [test], or `null` if there are none.
-  T? firstWhereOrNull(bool Function(T element) test) {
-    for (var element in this) {
-      if (test(element)) return element;
-    }
-    return null;
-  }
-}
\ No newline at end of file

From dc5db0bf23dd1a46cb8566087bfc18a5f4896167 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Wed, 13 Dec 2023 19:44:13 +0100
Subject: [PATCH 23/38] remove addMimeType and leave it for another time..

---
 pkgs/mime/lib/src/extension.dart   |  6 ------
 pkgs/mime/test/extension_test.dart | 14 --------------
 2 files changed, 20 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index b9160ed59..22b3e070a 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -39,9 +39,3 @@ String? extensionFromMime(String mimeType) {
   }
   return null;
 }
-
-/// Allow for a user-specified MIME type-extension mapping that overrides the
-/// default.
-void addMimeType(String mimeType, String extension) {
-  _preferredExtensionsMap[mimeType.toLowerCase()] = extension.toLowerCase();
-}
diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index a57e9c648..0a3db0fad 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -32,18 +32,4 @@ void main() {
       expect(extensionFromMime('application/to-be-invented'), isNull);
     });
   });
-
-  group('add-mime-type', () {
-    test('new-mime-type', () {
-      expect(extensionFromMime('custom/type'), isNull);
-      addMimeType('custom/type', 'ct');
-      expect(extensionFromMime('custom/type'), equals('ct'));
-    });
-
-    test('overridden-mime-type', () {
-      expect(extensionFromMime('image/jpeg'), equals('jpg'));
-      addMimeType('image/jpeg', 'jpeg');
-      expect(extensionFromMime('image/jpeg'), equals('jpeg'));
-    });
-  });
 }

From d285aae83d5dc2e6f17718711a4b8da35873c093 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Wed, 13 Dec 2023 20:53:17 +0100
Subject: [PATCH 24/38] remove addMimeType documentation

---
 pkgs/mime/README.md | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/pkgs/mime/README.md b/pkgs/mime/README.md
index 3bd4a482a..09675e899 100644
--- a/pkgs/mime/README.md
+++ b/pkgs/mime/README.md
@@ -68,12 +68,3 @@ print(extensionFromMime('text/html'));  // Will print html
 print(extensionFromMime('image/jpeg'));  // Will print jpg
 print(extensionFromMime('application/pdf'));  // Will print pdf
 ```
-
-You can override the default MIME type-extension mapping using
-`addMimeType`:
-
-```dart
-print(extensionFromMime('image/jpeg'));  // Will print jpg
-addMimeType('image/jpeg', 'jpeg');
-print(extensionFromMime('image/jpeg'));  // Will print jpeg
-```

From 342b63f57e4971cc002275b909e4a36ac083ae45 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Mon, 19 Feb 2024 19:00:11 +0100
Subject: [PATCH 25/38] be more specific about extension

---
 pkgs/mime/lib/src/extension.dart | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 22b3e070a..871ee55fb 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -23,7 +23,7 @@ final Map<String, String> _preferredExtensionsMap = <String, String>{
   'video/x-matroska': 'mkv',
 };
 
-/// The extension for a given MIME type.
+/// The file extension for a given MIME type.
 ///
 /// If there are multiple extensions for [mimeType], return preferred extension
 /// if defined, otherwise an extension chosen by the library.

From 40cd80c5a9f511578f1f730362ad5f5b0cea9ca0 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Mon, 19 Feb 2024 19:07:41 +0100
Subject: [PATCH 26/38] review feedback: avoid abbreviations, just overwrite
 function param

---
 pkgs/mime/lib/src/extension.dart | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 871ee55fb..e77b038a4 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -29,13 +29,13 @@ final Map<String, String> _preferredExtensionsMap = <String, String>{
 /// if defined, otherwise an extension chosen by the library.
 /// If no extension is found, `null` is returned.
 String? extensionFromMime(String mimeType) {
-  final mimeTypeLC = mimeType.toLowerCase();
-  if (_preferredExtensionsMap.containsKey(mimeTypeLC)) {
-    return _preferredExtensionsMap[mimeTypeLC]!;
+  mimeType = mimeType.toLowerCase();
+  if (_preferredExtensionsMap.containsKey(mimeType)) {
+    return _preferredExtensionsMap[mimeType]!;
   }
 
   for (final entry in defaultExtensionMap.entries) {
-    if (entry.value == mimeTypeLC) return entry.key;
+    if (entry.value == mimeType) return entry.key;
   }
   return null;
 }

From 60730a6dbc5842d8a0856e41f9f42a0548dcd5c4 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Mon, 19 Feb 2024 19:25:01 +0100
Subject: [PATCH 27/38] since extensions can no longer by added at runtime, we
 can optimize and avoid the linear search

---
 pkgs/mime/lib/src/extension.dart | 43 ++++++++++++++------------------
 1 file changed, 19 insertions(+), 24 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index e77b038a4..5b223a37c 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -6,22 +6,24 @@ import 'default_extension_map.dart';
 
 /// Add an override for common extensions since different extensions may map
 /// to the same MIME type.
-final Map<String, String> _preferredExtensionsMap = <String, String>{
-  'application/vnd.ms-excel': 'xls',
-  'application/vnd.ms-powerpoint': 'ppt',
-  'image/jpeg': 'jpg',
-  'image/tiff': 'tif',
-  'image/svg+xml': 'svg',
-  'text/calendar': 'ics',
-  'text/javascript': 'js',
-  'text/plain': 'txt',
-  'text/sgml': 'sgml',
-  'text/x-pascal': 'pas',
-  'video/mp4': 'mp4',
-  'video/mpeg': 'mpg',
-  'video/quicktime': 'mov',
-  'video/x-matroska': 'mkv',
-};
+final Map<String, String> _defaultMimeTypeMap = {
+  for (var entry in defaultExtensionMap.entries) entry.value: entry.key,
+}..addAll({
+    'application/vnd.ms-excel': 'xls',
+    'application/vnd.ms-powerpoint': 'ppt',
+    'image/jpeg': 'jpg',
+    'image/tiff': 'tif',
+    'image/svg+xml': 'svg',
+    'text/calendar': 'ics',
+    'text/javascript': 'js',
+    'text/plain': 'txt',
+    'text/sgml': 'sgml',
+    'text/x-pascal': 'pas',
+    'video/mp4': 'mp4',
+    'video/mpeg': 'mpg',
+    'video/quicktime': 'mov',
+    'video/x-matroska': 'mkv',
+  });
 
 /// The file extension for a given MIME type.
 ///
@@ -30,12 +32,5 @@ final Map<String, String> _preferredExtensionsMap = <String, String>{
 /// If no extension is found, `null` is returned.
 String? extensionFromMime(String mimeType) {
   mimeType = mimeType.toLowerCase();
-  if (_preferredExtensionsMap.containsKey(mimeType)) {
-    return _preferredExtensionsMap[mimeType]!;
-  }
-
-  for (final entry in defaultExtensionMap.entries) {
-    if (entry.value == mimeType) return entry.key;
-  }
-  return null;
+  return _defaultMimeTypeMap[mimeType];
 }

From 04f81695acfdb1a8dc181db72c90b1e9e3c23c63 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Mon, 19 Feb 2024 19:27:23 +0100
Subject: [PATCH 28/38] local var no longer needed

---
 pkgs/mime/lib/src/extension.dart | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 5b223a37c..1edaca2c4 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -30,7 +30,5 @@ final Map<String, String> _defaultMimeTypeMap = {
 /// If there are multiple extensions for [mimeType], return preferred extension
 /// if defined, otherwise an extension chosen by the library.
 /// If no extension is found, `null` is returned.
-String? extensionFromMime(String mimeType) {
-  mimeType = mimeType.toLowerCase();
-  return _defaultMimeTypeMap[mimeType];
-}
+String? extensionFromMime(String mimeType) =>
+    _defaultMimeTypeMap[mimeType.toLowerCase()];

From 8ba5efba9f091316c27fb821fd30870c7db8c679 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Mon, 19 Feb 2024 19:34:51 +0100
Subject: [PATCH 29/38] update docs

---
 pkgs/mime/CONTRIBUTING.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/mime/CONTRIBUTING.md b/pkgs/mime/CONTRIBUTING.md
index bd079dd62..463063ae4 100644
--- a/pkgs/mime/CONTRIBUTING.md
+++ b/pkgs/mime/CONTRIBUTING.md
@@ -34,4 +34,4 @@ one above, the
 
 ### Adding an extension / MIME type mapping
 If a MIME type ends up with multiple extensions, it is recommended to define a 
-preferred extension in `_preferredExtensionsMap` in [extension.dart](lib/src/extension.dart). 
\ No newline at end of file
+preferred extension in `_defaultMimeTypeMap` in [extension.dart](lib/src/extension.dart). 
\ No newline at end of file

From c1d7b69657f2a698ff5200e5a3f93eed5cd38549 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Mon, 19 Feb 2024 19:38:56 +0100
Subject: [PATCH 30/38] update docs

---
 pkgs/mime/lib/src/extension.dart | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 1edaca2c4..35a860f88 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -4,8 +4,8 @@
 
 import 'default_extension_map.dart';
 
-/// Add an override for common extensions since different extensions may map
-/// to the same MIME type.
+/// Reverse map of [defaultExtensionMap] with overrides for common extensions
+/// since different extensions may map to the same MIME type.
 final Map<String, String> _defaultMimeTypeMap = {
   for (var entry in defaultExtensionMap.entries) entry.value: entry.key,
 }..addAll({
@@ -28,7 +28,9 @@ final Map<String, String> _defaultMimeTypeMap = {
 /// The file extension for a given MIME type.
 ///
 /// If there are multiple extensions for [mimeType], return preferred extension
-/// if defined, otherwise an extension chosen by the library.
+/// if defined in [_defaultMimeTypeMap], otherwise an extension chosen by the
+/// library.
+///
 /// If no extension is found, `null` is returned.
 String? extensionFromMime(String mimeType) =>
     _defaultMimeTypeMap[mimeType.toLowerCase()];

From e654a3275ddb3a63e76174d11ea77951d2daa871 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Tue, 27 Aug 2024 16:14:34 +0200
Subject: [PATCH 31/38] documentation updates

---
 pkgs/mime/README.md              |  6 +++---
 pkgs/mime/lib/src/extension.dart | 21 ++++++++++++++-------
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/pkgs/mime/README.md b/pkgs/mime/README.md
index 09675e899..da06de62b 100644
--- a/pkgs/mime/README.md
+++ b/pkgs/mime/README.md
@@ -64,7 +64,7 @@ The top level function `extensionFromMime` can be used to determine the
 file extension of a given MIME type.
 
 ```dart
-print(extensionFromMime('text/html'));  // Will print html
-print(extensionFromMime('image/jpeg'));  // Will print jpg
-print(extensionFromMime('application/pdf'));  // Will print pdf
+print(extensionFromMime('text/html'));  // Prints "html".
+print(extensionFromMime('image/jpeg'));  // Prints "jpg".
+print(extensionFromMime('application/pdf'));  // Prints "pdf".
 ```
diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 35a860f88..63234b6bf 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -4,8 +4,14 @@
 
 import 'default_extension_map.dart';
 
-/// Reverse map of [defaultExtensionMap] with overrides for common extensions
-/// since different extensions may map to the same MIME type.
+/// Default extension for recognized MIME types.
+///
+/// Is the inverse of [defaultExtensionMap], and where that
+/// map has multiple extensions which map to the same
+/// MIME type, this map maps that MIME type to a *default*
+/// extension.
+///
+/// Used by [extensionFromMime].
 final Map<String, String> _defaultMimeTypeMap = {
   for (var entry in defaultExtensionMap.entries) entry.value: entry.key,
 }..addAll({
@@ -25,12 +31,13 @@ final Map<String, String> _defaultMimeTypeMap = {
     'video/x-matroska': 'mkv',
   });
 
-/// The file extension for a given MIME type.
+/// The default file extension for a given MIME type.
 ///
-/// If there are multiple extensions for [mimeType], return preferred extension
-/// if defined in [_defaultMimeTypeMap], otherwise an extension chosen by the
-/// library.
+/// If [mimeType] has multiple associated extensions,
+/// the returned string is one of those, chosen as the default
+/// extension for that MIME type.
 ///
-/// If no extension is found, `null` is returned.
+/// Returns `null` if [mimeType] is not a recognized and
+/// supported MIME type.
 String? extensionFromMime(String mimeType) =>
     _defaultMimeTypeMap[mimeType.toLowerCase()];

From c236bd85caa4a3991cf55478be263dd2430cb98f Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Tue, 27 Aug 2024 16:15:04 +0200
Subject: [PATCH 32/38] remove unnecessary addAll

---
 pkgs/mime/lib/src/extension.dart | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index 63234b6bf..db4bff482 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -14,22 +14,21 @@ import 'default_extension_map.dart';
 /// Used by [extensionFromMime].
 final Map<String, String> _defaultMimeTypeMap = {
   for (var entry in defaultExtensionMap.entries) entry.value: entry.key,
-}..addAll({
-    'application/vnd.ms-excel': 'xls',
-    'application/vnd.ms-powerpoint': 'ppt',
-    'image/jpeg': 'jpg',
-    'image/tiff': 'tif',
-    'image/svg+xml': 'svg',
-    'text/calendar': 'ics',
-    'text/javascript': 'js',
-    'text/plain': 'txt',
-    'text/sgml': 'sgml',
-    'text/x-pascal': 'pas',
-    'video/mp4': 'mp4',
-    'video/mpeg': 'mpg',
-    'video/quicktime': 'mov',
-    'video/x-matroska': 'mkv',
-  });
+  'application/vnd.ms-excel': 'xls',
+  'application/vnd.ms-powerpoint': 'ppt',
+  'image/jpeg': 'jpg',
+  'image/tiff': 'tif',
+  'image/svg+xml': 'svg',
+  'text/calendar': 'ics',
+  'text/javascript': 'js',
+  'text/plain': 'txt',
+  'text/sgml': 'sgml',
+  'text/x-pascal': 'pas',
+  'video/mp4': 'mp4',
+  'video/mpeg': 'mpg',
+  'video/quicktime': 'mov',
+  'video/x-matroska': 'mkv',
+};
 
 /// The default file extension for a given MIME type.
 ///

From b11854c5e97645c043a7d96b8baf7ebf7cd5eddd Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Tue, 27 Aug 2024 16:15:17 +0200
Subject: [PATCH 33/38] remove unnecessary group

---
 pkgs/mime/test/extension_test.dart | 44 ++++++++++++++----------------
 1 file changed, 21 insertions(+), 23 deletions(-)

diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index 0a3db0fad..cf8429e01 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -6,30 +6,28 @@ import 'package:mime/mime.dart';
 import 'package:test/test.dart';
 
 void main() {
-  group('global-lookup-mime-type', () {
-    test('valid-mime-type', () {
-      expect(extensionFromMime('text/x-dart'), equals('dart'));
-      expect(extensionFromMime('text/javascript'), equals('js'));
-      expect(extensionFromMime('application/java-archive'), equals('jar'));
-      expect(extensionFromMime('application/json'), equals('json'));
-      expect(extensionFromMime('application/pdf'), equals('pdf'));
-      expect(extensionFromMime('application/vnd.ms-excel'), equals('xls'));
-      expect(extensionFromMime('application/xhtml+xml'), equals('xht'));
-      expect(extensionFromMime('image/jpeg'), equals('jpg'));
-      expect(extensionFromMime('image/png'), equals('png'));
-      expect(extensionFromMime('text/css'), equals('css'));
-      expect(extensionFromMime('text/html'), equals('htm'));
-      expect(extensionFromMime('text/plain'), equals('txt'));
-      expect(extensionFromMime('text/x-c'), equals('c'));
-    });
+  test('valid-mime-type', () {
+    expect(extensionFromMime('text/x-dart'), equals('dart'));
+    expect(extensionFromMime('text/javascript'), equals('js'));
+    expect(extensionFromMime('application/java-archive'), equals('jar'));
+    expect(extensionFromMime('application/json'), equals('json'));
+    expect(extensionFromMime('application/pdf'), equals('pdf'));
+    expect(extensionFromMime('application/vnd.ms-excel'), equals('xls'));
+    expect(extensionFromMime('application/xhtml+xml'), equals('xht'));
+    expect(extensionFromMime('image/jpeg'), equals('jpg'));
+    expect(extensionFromMime('image/png'), equals('png'));
+    expect(extensionFromMime('text/css'), equals('css'));
+    expect(extensionFromMime('text/html'), equals('htm'));
+    expect(extensionFromMime('text/plain'), equals('txt'));
+    expect(extensionFromMime('text/x-c'), equals('c'));
+  });
 
-    test('invalid-mime-type', () {
-      expect(extensionFromMime('invalid-mime-type'), isNull);
-      expect(extensionFromMime('invalid/mime/type'), isNull);
-    });
+  test('invalid-mime-type', () {
+    expect(extensionFromMime('invalid-mime-type'), isNull);
+    expect(extensionFromMime('invalid/mime/type'), isNull);
+  });
 
-    test('unknown-mime-type', () {
-      expect(extensionFromMime('application/to-be-invented'), isNull);
-    });
+  test('unknown-mime-type', () {
+    expect(extensionFromMime('application/to-be-invented'), isNull);
   });
 }

From 874f740028311418d6cd9f3655b38ed992aaa66d Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Tue, 27 Aug 2024 16:22:59 +0200
Subject: [PATCH 34/38] bump version + add changelog

---
 pkgs/mime/CHANGELOG.md | 4 ++++
 pkgs/mime/pubspec.yaml | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/pkgs/mime/CHANGELOG.md b/pkgs/mime/CHANGELOG.md
index 50f243306..483c35f90 100644
--- a/pkgs/mime/CHANGELOG.md
+++ b/pkgs/mime/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.0.7-wip
+
+* Update `extensionFromMime` to return a default extension when a MIME type maps to multiple extensions.
+
 ## 1.0.6
 
 * Add `topics` section to `pubspec.yaml`.
diff --git a/pkgs/mime/pubspec.yaml b/pkgs/mime/pubspec.yaml
index 8d3c49823..f1208681e 100644
--- a/pkgs/mime/pubspec.yaml
+++ b/pkgs/mime/pubspec.yaml
@@ -1,5 +1,5 @@
 name: mime
-version: 1.0.6
+version: 1.0.7-wip
 description: >-
   Utilities for handling media (MIME) types, including determining a type from
   a file extension and file contents.

From d5e3d4765f28cff191b811d67aa271bd6b779fa9 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Wed, 28 Aug 2024 18:25:34 +0200
Subject: [PATCH 35/38] remove superfluous line

---
 pkgs/mime/test/mime_type_test.dart | 1 -
 1 file changed, 1 deletion(-)

diff --git a/pkgs/mime/test/mime_type_test.dart b/pkgs/mime/test/mime_type_test.dart
index 56efba88b..23cb34af3 100644
--- a/pkgs/mime/test/mime_type_test.dart
+++ b/pkgs/mime/test/mime_type_test.dart
@@ -317,5 +317,4 @@ void main() {
 
     expect(initialMagicNumbersMaxLength, actualMaxBytes);
   });
-
 }

From 7b3193f26fd4c2267244d152386f457ef7a4cec4 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Thu, 29 Aug 2024 16:52:00 +0200
Subject: [PATCH 36/38] breaking release because of removed method

---
 pkgs/mime/CHANGELOG.md | 3 ++-
 pkgs/mime/pubspec.yaml | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/pkgs/mime/CHANGELOG.md b/pkgs/mime/CHANGELOG.md
index 483c35f90..3f6dd9684 100644
--- a/pkgs/mime/CHANGELOG.md
+++ b/pkgs/mime/CHANGELOG.md
@@ -1,5 +1,6 @@
-## 1.0.7-wip
+## 2.0.0-wip
 
+* **[Breaking]** `extensionFromMime(String mimeType, {String? orElse})` has been removed. Use `extensionFromMime(String mimeType) ?? orElse` instead.
 * Update `extensionFromMime` to return a default extension when a MIME type maps to multiple extensions.
 
 ## 1.0.6
diff --git a/pkgs/mime/pubspec.yaml b/pkgs/mime/pubspec.yaml
index f1208681e..2cfa75a33 100644
--- a/pkgs/mime/pubspec.yaml
+++ b/pkgs/mime/pubspec.yaml
@@ -1,5 +1,5 @@
 name: mime
-version: 1.0.7-wip
+version: 2.0.0-wip
 description: >-
   Utilities for handling media (MIME) types, including determining a type from
   a file extension and file contents.

From c33a7eaa3e20a797b9b4cde66585dd939d40eb4e Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Thu, 29 Aug 2024 17:18:01 +0200
Subject: [PATCH 37/38] add some more default extensions

---
 pkgs/mime/lib/src/extension.dart   | 13 +++++++++++++
 pkgs/mime/test/extension_test.dart |  4 ++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/pkgs/mime/lib/src/extension.dart b/pkgs/mime/lib/src/extension.dart
index db4bff482..293449a0e 100644
--- a/pkgs/mime/lib/src/extension.dart
+++ b/pkgs/mime/lib/src/extension.dart
@@ -14,15 +14,28 @@ import 'default_extension_map.dart';
 /// Used by [extensionFromMime].
 final Map<String, String> _defaultMimeTypeMap = {
   for (var entry in defaultExtensionMap.entries) entry.value: entry.key,
+  'application/msword': 'doc',
   'application/vnd.ms-excel': 'xls',
   'application/vnd.ms-powerpoint': 'ppt',
+  'application/x-debian-package': 'deb',
+  'application/xhtml+xml': 'xhtml',
+  'application/xml': 'xml',
+  'audio/x-aiff': 'aif',
+  'audio/midi': 'mid',
+  'audio/mp4': 'm4a',
+  'audio/ogg': 'ogg',
   'image/jpeg': 'jpg',
   'image/tiff': 'tif',
   'image/svg+xml': 'svg',
+  'model/vrml': 'vrml',
   'text/calendar': 'ics',
+  'text/html': 'html',
   'text/javascript': 'js',
+  'text/markdown': 'md',
   'text/plain': 'txt',
   'text/sgml': 'sgml',
+  'text/x-asm': 'asm',
+  'text/x-c': 'c',
   'text/x-pascal': 'pas',
   'video/mp4': 'mp4',
   'video/mpeg': 'mpg',
diff --git a/pkgs/mime/test/extension_test.dart b/pkgs/mime/test/extension_test.dart
index cf8429e01..40dae6df5 100644
--- a/pkgs/mime/test/extension_test.dart
+++ b/pkgs/mime/test/extension_test.dart
@@ -13,11 +13,11 @@ void main() {
     expect(extensionFromMime('application/json'), equals('json'));
     expect(extensionFromMime('application/pdf'), equals('pdf'));
     expect(extensionFromMime('application/vnd.ms-excel'), equals('xls'));
-    expect(extensionFromMime('application/xhtml+xml'), equals('xht'));
+    expect(extensionFromMime('application/xhtml+xml'), equals('xhtml'));
     expect(extensionFromMime('image/jpeg'), equals('jpg'));
     expect(extensionFromMime('image/png'), equals('png'));
     expect(extensionFromMime('text/css'), equals('css'));
-    expect(extensionFromMime('text/html'), equals('htm'));
+    expect(extensionFromMime('text/html'), equals('html'));
     expect(extensionFromMime('text/plain'), equals('txt'));
     expect(extensionFromMime('text/x-c'), equals('c'));
   });

From b5e69814d84ba23f8b5df9f158cf90be6d79c3e1 Mon Sep 17 00:00:00 2001
From: matthias sweertvaegher <121732-mx1up@users.noreply.gitlab.com>
Date: Fri, 30 Aug 2024 12:23:10 +0200
Subject: [PATCH 38/38] document breaking change correctly

---
 pkgs/mime/CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/mime/CHANGELOG.md b/pkgs/mime/CHANGELOG.md
index 3f6dd9684..55332bac0 100644
--- a/pkgs/mime/CHANGELOG.md
+++ b/pkgs/mime/CHANGELOG.md
@@ -1,6 +1,6 @@
 ## 2.0.0-wip
 
-* **[Breaking]** `extensionFromMime(String mimeType, {String? orElse})` has been removed. Use `extensionFromMime(String mimeType) ?? orElse` instead.
+* **[Breaking]** `extensionFromMime(String mimeType)` returns `null` instead of `mimeType` for an unknown mime type.
 * Update `extensionFromMime` to return a default extension when a MIME type maps to multiple extensions.
 
 ## 1.0.6