Fix incorrectly treating extension-less file name as extension

HISTORY.md

@@ -1,6 +1,8 @@
 unreleased
 ==========
 
+  * Fix incorrectly treating extension-less file name as extension
+    - i.e. `'path/to/json'` will no longer return `application/json`
   * Refactor internals for readability and no argument reassignment
 
 2.0.14 / 2015-06-06

README.md

@@ -42,10 +42,11 @@ All functions return `false` if input is invalid or not found.
 Lookup the content-type associated with a file.
 
 ```js
-mime.lookup('json')           // 'application/json'
-mime.lookup('.md')            // 'text/x-markdown'
-mime.lookup('file.html')      // 'text/html'
-mime.lookup('folder/file.js') // 'application/javascript'
+mime.lookup('json')             // 'application/json'
+mime.lookup('.md')              // 'text/x-markdown'
+mime.lookup('file.html')        // 'text/html'
+mime.lookup('folder/file.js')   // 'application/javascript'
+mime.lookup('folder/.htaccess') // false
 
 mime.lookup('cats') // false
 ```

index.js

@@ -11,6 +11,7 @@
  */
 
 var db = require('mime-db')
+var extname = require('path').extname
 
 /**
  * Module exports.
@@ -110,25 +111,27 @@ function extension(type) {
 }
 
 /**
- * Lookup the MIME type for a file name/extension.
+ * Lookup the MIME type for a file path/extension.
  *
- * @param {string} name
+ * @param {string} path
  * @return {boolean|string}
  */
 
-function lookup(name) {
-  if (!name || typeof name !== 'string') {
+function lookup(path) {
+  if (!path || typeof path !== 'string') {
     return false
   }
 
-  // remove any leading paths, though we should just use path.basename
-  var ext = name.replace(/.*[\.\/\\]/, '').toLowerCase()
+  // get the extension ("ext" or ".ext" or full path)
+  var extension = extname('x.' + path)
+    .toLowerCase()
+    .substr(1)
 
-  if (!ext) {
+  if (!extension) {
     return false
   }
 
-  return exports.types[ext] || false
+  return exports.types[extension] || false
 }
 
 /**

test/mime.js

@@ -14,14 +14,6 @@ function eq(a, b) {
 console.log(Object.keys(mime.extensions).length + ' types');
 console.log(Object.keys(mime.types).length + ' extensions\n');
 
-//
-// Test mime lookups
-//
-
-eq('text/plain', mime.lookup('.text.txt'));    // hidden file
-eq('text/plain', mime.lookup('/txt'));         // extension-less ()
-eq('text/plain', mime.lookup('\\txt'));        // Windows, extension-less
-
 //
 // Test extensions
 //

test/test.js

@@ -3,7 +3,7 @@ var assert = require('assert')
 var mimeTypes = require('..')
 
 describe('mimeTypes', function () {
-  describe('.extension(path)', function () {
+  describe('.extension(type)', function () {
     it('should return extension for mime type', function () {
       assert.equal(mimeTypes.extension('text/html'), 'html')
     })
@@ -75,19 +75,40 @@ describe('mimeTypes', function () {
 
     it('should return mime type for relative path', function () {
       assert.equal(mimeTypes.lookup('path/to/page.html'), 'text/html')
+      assert.equal(mimeTypes.lookup('path\\to\\page.html'), 'text/html')
     })
 
     it('should return mime type for absolute path', function () {
       assert.equal(mimeTypes.lookup('/path/to/page.html'), 'text/html')
+      assert.equal(mimeTypes.lookup('C:\\path\\to\\page.html'), 'text/html')
     })
 
     it('should be case insensitive', function () {
       assert.equal(mimeTypes.lookup('/path/to/PAGE.HTML'), 'text/html')
+      assert.equal(mimeTypes.lookup('C:\\path\\to\\PAGE.HTML'), 'text/html')
     })
 
     it('should return false for unknown extension', function () {
       assert.strictEqual(mimeTypes.lookup('/path/to/file.bogus'), false)
     })
+
+    it('should return false for path without extension', function () {
+      assert.strictEqual(mimeTypes.lookup('/path/to/json'), false)
+    })
+
+    describe('path with dotfile', function () {
+      it('should return false when extension-less', function () {
+        assert.strictEqual(mimeTypes.lookup('/path/to/.json'), false)
+      })
+
+      it('should return mime type when there is extension', function () {
+        assert.strictEqual(mimeTypes.lookup('/path/to/.config.json'), 'application/json')
+      })
+
+      it('should return mime type when there is extension, but no path', function () {
+        assert.strictEqual(mimeTypes.lookup('.config.json'), 'application/json')
+      })
+    })
   })
 })