extensionFromMime(String mimeType) returns null instead of mimeType for an unknown mime type.extensionFromMime to return a default extension when a MIME type maps to multiple extensions.topics section to pubspec.yaml.dart-lang/tools monorepo.video/mp4 mimeType lookup by header bytes.image/heic mimeType lookup by header bytes.image/heif mimeType lookup by header bytes.text/markdown mimeType lookup by extension..js to text/javascript per https://datatracker.ietf.org/doc/html/rfc9239..mjs as text/javascript.application/dicom mimeType lookup by extension.extensionFromMime utility function.application/dart to text/x-dart.<3.0.0, and adjust other dependencies.Updates to support Dart 2.0 core library changes (wave 2.2). See issue 31847 for details.
Updated Dart SDK requirement to >= 1.8.3 <2.0.0
Strong-mode clean.
Added support for glTF text and binary formats.