minor: case-insensitive input, lowercase output (fixes #224)

Mime.js

@@ -38,7 +38,9 @@ function Mime() {
  */
 Mime.prototype.define = function(typeMap, force) {
   for (var type in typeMap) {
-    var extensions = typeMap[type];
+    var extensions = typeMap[type].map(t => t.toLowerCase());
+    type = type.toLowerCase();
+
     for (var i = 0; i < extensions.length; i++) {
       var ext = extensions[i];
 

README.md

@@ -99,6 +99,9 @@ Module | Size
 Both `require('mime')` and `require('mime/lite')` return instances of the MIME
 class, documented below.
 
+Note: Inputs to this API are case-insensitive.  Outputs (returned values) will
+be lowercase.
+
 ### new Mime(typeMap, ... more maps)
 
 Most users of this module will not need to create Mime instances directly.

src/README_js.md

@@ -98,6 +98,9 @@ Module | Size
 Both `require('mime')` and `require('mime/lite')` return instances of the MIME
 class, documented below.
 
+Note: Inputs to this API are case-insensitive.  Outputs (returned values) will
+be lowercase.
+
 ### new Mime(typeMap, ... more maps)
 
 Most users of this module will not need to create Mime instances directly.

src/test.js

@@ -76,6 +76,24 @@ describe('class Mime', function() {
     });
   });
 
+  it ('case-insensitive', function() {
+    var Mime = require('../Mime');
+    const mime = new Mime({
+      'TEXT/UPPER': ['UP'],
+      'text/lower': ['low'],
+    });
+
+    assert.equal(mime.getType('test.up'), 'text/upper');
+    assert.equal(mime.getType('test.UP'), 'text/upper');
+    assert.equal(mime.getType('test.low'), 'text/lower');
+    assert.equal(mime.getType('test.LOW'), 'text/lower');
+
+    assert.equal(mime.getExtension('text/upper'), 'up');
+    assert.equal(mime.getExtension('text/lower'), 'low');
+    assert.equal(mime.getExtension('TEXT/UPPER'), 'up');
+    assert.equal(mime.getExtension('TEXT/LOWER'), 'low');
+  });
+
   it('getType()', function() {
     // Upper/lower case
     assert.equal(mime.getType('text.txt'), 'text/plain');