fix: Improve getFileExtension() readability and handle leading dot extensions. (#8980)

Author: damanV5

src/js/utils/url.js

@@ -47,14 +47,12 @@ export const getAbsoluteURL = function(url) {
  */
 export const getFileExtension = function(path) {
   if (typeof path === 'string') {
-    const splitPathRe = /^(\/?)([\s\S]*?)((?:\.{1,2}|[^\/]+?)(\.([^\.\/\?]+)))(?:[\/]*|[\?].*)$/;
-    const pathParts = splitPathRe.exec(path);
+    const cleanPath = path.split('?')[0].replace(/\/+$/, '');
 
-    if (pathParts) {
-      return pathParts.pop().toLowerCase();
-    }
-  }
+    const match = cleanPath.match(/\.([^.\/]+)$/);
 
+    return match ? match[1].toLowerCase() : '';
+  }
   return '';
 };
 
@@ -74,3 +72,4 @@ export const getFileExtension = function(path) {
 export const isCrossOrigin = function(url, winLoc = window.location) {
   return parseUrl(url).origin !== winLoc.origin;
 };
+

test/unit/utils/url.test.js

@@ -55,6 +55,9 @@ QUnit.test('should get the file extension of the passed path', function(assert)
   assert.equal(Url.getFileExtension('foo/.bar/test.video.flv?foo=bar'), 'flv');
   assert.equal(Url.getFileExtension('http://www.test.com/video.mp4'), 'mp4');
   assert.equal(Url.getFileExtension('http://foo/bar/test.video.wgg'), 'wgg');
+  assert.equal(Url.getFileExtension('http://www.test.com/video/.mp4'), 'mp4');
+  assert.equal(Url.getFileExtension('http://www.test.com/video/.mp4/'), 'mp4');
+  assert.equal(Url.getFileExtension('http://www.test.com/video.mp4/'), 'mp4');
 
   // edge cases
   assert.equal(Url.getFileExtension('http://...'), '');