{{pkg.description}}
All MIME type mappings are based on mime-db
(2023-02-17). For filesize reasons only a small selected
number
of vendor MIME types (aka
*/vnd.*
) are included. Most of the omitted ones are fairly obscure anyway, so
likely not problematic...
Additionally, this package defines some MIME types not included in the original DB, as well as some preference overrides.
{{meta.status}}
{{repo.supportPackages}}
{{repo.relatedPackages}}
{{meta.blogPosts}}
{{pkg.install}}
{{pkg.size}}
{{pkg.deps}}
{{repo.examples}}
{{pkg.docs}}
This package exposes a MIME_TYPES
object which provides
mappings from file extensions to MIME types. For each extension one or
more MIME types are provided, with the default type always in first
position.
import { MIME_TYPES } from "@thi.ng/mime";
MIME_TYPES.mp3
// [ 'audio/mpeg', 'audio/mp3' ]
MIME_TYPES.jpg
// [ 'image/jpeg' ]
MIME_TYPES.jpeg
// [ 'image/jpeg' ]
To simplify lookup and support a fallback type, the package has
preferredType()
function:
import { preferredType } from "@thi.ng/mime";
preferredType("mp3")
// "audio/mpeg"
// unknown file extension w/ default fallback type
preferredType("foo")
// "application/octet-stream"
// unknown file extension w/ given fallback type
preferredType("foo", "text/plain")
// "text/plain"
Reverse lookups are possible too, using preferredExtension()
(also supports fallback):
import { preferredExtension } from "@thi.ng/mime";
preferredExtension("image/svg+xml");
// "svg"
preferredExtension("image/foo");
// "bin" (default fallback)
preferredExtension("image/foo", "dat");
// "dat" (custom fallback)
The original mime-db includes information
if a MIME type is compressible (gzippable). This information can be obtained via
isCompressible()
. Note: Some of these decisions seem to be questionable/wrong
(e.g. many plain text formats are marked as false), but taken here as
provided...
import { isCompressible } from "@thi.ng/mime";
isCompressible("text/javascript");
// true
isCompressible(preferredType("mp4"))
// false
- Download the latest version of mime-db's JSON
index and
save it to
[packages/mime/]tools/mime-db.json
- Run the following command to build an up-to-date index (assumes the umbrella
repo has been pre-built already). Output will always be be written to
src/generated.ts
.
# from the thi.ng/umbrella repo root
(cd packages/mime && yarn tool:convert)
Additional configuration options are available in the
tools/convert.ts
script.