Added a new method to get all extensions.

README.md

@@ -71,6 +71,15 @@ Get the default extension for a content-type.
 mime.extension('application/octet-stream') // 'bin'
 ```
 
+
+### mime.allExtensions(type)
+
+Get all the extensions for a content-type.
+
+```js
+mime.allExtensions('audio/mpeg') // ["mpga", "mp2", "mp2a", "mp3", "m2a", "m3a"]
+```
+
 ### mime.charset(type)
 
 Lookup the implied default charset of a content-type.

index.js

@@ -32,6 +32,7 @@ exports.charset = charset
 exports.charsets = { lookup: charset }
 exports.contentType = contentType
 exports.extension = extension
+exports.allExtensions = allExtensions
 exports.extensions = Object.create(null)
 exports.lookup = lookup
 exports.types = Object.create(null)
@@ -105,6 +106,19 @@ function contentType (str) {
  */
 
 function extension (type) {
+  var extensions = allExtensions(type)
+
+  return extensions ? extensions[0] : extensions
+}
+
+/**
+ * Get all the extensions for a MIME type.
+ *
+ * @param {string} type
+ * @return {boolean|Array}
+ */
+
+function allExtensions (type) {
   if (!type || typeof type !== 'string') {
     return false
   }
@@ -119,7 +133,7 @@ function extension (type) {
     return false
   }
 
-  return exts[0]
+  return exts
 }
 
 /**

test/test.js

@@ -134,6 +134,37 @@ describe('mimeTypes', function () {
     })
   })
 
+  describe('.allExtensions(type)', function () {
+    it('should return a list of extensions for mime type', function () {
+      assert.deepEqual(mimeTypes.allExtensions('text/html'), ['html', 'htm', 'shtml'])
+      assert.deepEqual(mimeTypes.allExtensions(' text/html'), ['html', 'htm', 'shtml'])
+      assert.deepEqual(mimeTypes.allExtensions('text/html '), ['html', 'htm', 'shtml'])
+    })
+
+    it('should return false for unknown type', function () {
+      assert.strictEqual(mimeTypes.allExtensions('application/x-bogus'), false)
+    })
+
+    it('should return false for non-type string', function () {
+      assert.strictEqual(mimeTypes.allExtensions('bogus'), false)
+    })
+
+    it('should return false for non-strings', function () {
+      assert.strictEqual(mimeTypes.allExtensions(null), false)
+      assert.strictEqual(mimeTypes.allExtensions(undefined), false)
+      assert.strictEqual(mimeTypes.allExtensions(42), false)
+      assert.strictEqual(mimeTypes.allExtensions({}), false)
+    })
+
+    it('should return extension for mime type with parameters', function () {
+      assert.deepEqual(mimeTypes.allExtensions('text/html;charset=UTF-8'), ['html', 'htm', 'shtml'])
+      assert.deepEqual(mimeTypes.allExtensions('text/HTML; charset=UTF-8'), ['html', 'htm', 'shtml'])
+      assert.deepEqual(mimeTypes.allExtensions('text/html; charset=UTF-8'), ['html', 'htm', 'shtml'])
+      assert.deepEqual(mimeTypes.allExtensions('text/html; charset=UTF-8 '), ['html', 'htm', 'shtml'])
+      assert.deepEqual(mimeTypes.allExtensions('text/html ; charset=UTF-8'), ['html', 'htm', 'shtml'])
+    })
+  })
+
   describe('.lookup(extension)', function () {
     it('should return mime type for ".html"', function () {
       assert.equal(mimeTypes.lookup('.html'), 'text/html')