feat: allow xhr override globally, for super advanced use cases only (#1059)

We have the recommended `beforeRequest` method but due to timing, it's not possible to use this to be able to set options for the initial m3u8 manifest as well. This makes it so that the XHR method can be overridden completely.

src/xhr.js

@@ -74,7 +74,11 @@ const xhrFactory = function() {
       }
     }
 
-    const request = videojsXHR(options, function(error, response) {
+    // Use the standard videojs.xhr() method unless `videojs.Vhs.xhr` has been overriden
+    // TODO: switch back to videojs.Vhs.xhr.name === 'XhrFunction' when we drop IE11
+    const xhrMethod = videojs.Vhs.xhr.original === true ? videojsXHR : videojs.Vhs.xhr;
+
+    const request = xhrMethod(options, function(error, response) {
       return callbackWrapper(request, error, response, callback);
     });
     const originalAbort = request.abort;
@@ -88,6 +92,8 @@ const xhrFactory = function() {
     return request;
   };
 
+  xhr.original = true;
+
   return xhr;
 };
 

test/videojs-http-streaming.test.js

@@ -4267,6 +4267,36 @@ QUnit.test('Allows specifying the beforeRequest function globally', function(ass
   assert.equal(this.player.tech_.vhs.stats.bandwidth, 4194304, 'default');
 });
 
+QUnit.test('Allows specifying custom xhr() function globally', function(assert) {
+  const originalXhr = videojs.Vhs.xhr;
+  let customXhr = false;
+
+  videojs.Vhs.xhr = function(opts, callback) {
+    customXhr = true;
+    return videojs.xhr(opts, function(err, response, body) {
+      callback(err, response);
+    });
+  };
+
+  this.player.src({
+    src: 'master.m3u8',
+    type: 'application/vnd.apple.mpegurl'
+  });
+
+  this.clock.tick(1);
+
+  openMediaSource(this.player, this.clock);
+  // master
+  this.standardXHRResponse(this.requests.shift());
+
+  assert.ok(customXhr, 'customXhr was called');
+
+  videojs.Vhs.xhr = originalXhr;
+
+  // verify stats
+  assert.equal(this.player.tech_.vhs.stats.bandwidth, 4194304, 'default');
+});
+
 QUnit.test('Allows overriding the global beforeRequest function', function(assert) {
   let beforeGlobalRequestCalled = 0;
   let beforeLocalRequestCalled = 0;