Merge pull request bugsnag#582 from bugsnag/remove-event-listener-bug

fix(plugin-inline-script-content): Ensure event handlers added before Bugsnag can be removed

Author: bengourley

packages/plugin-inline-script-content/inline-script-content.js

@@ -102,20 +102,23 @@ module.exports = {
       'Notification', 'SVGElementInstance', 'Screen', 'TextTrack', 'TextTrackCue', 'TextTrackList',
       'WebSocket', 'WebSocketWorker', 'Worker', 'XMLHttpRequest', 'XMLHttpRequestEventTarget', 'XMLHttpRequestUpload'
     ], o => {
-      if (!win[o] || !win[o].prototype || typeof win[o].prototype.addEventListener !== 'function') return
+      if (!win[o] || !win[o].prototype || !win[o].prototype.hasOwnProperty || !win[o].prototype.hasOwnProperty('addEventListener')) return
       __proxy(win[o].prototype, 'addEventListener', original =>
         __traceOriginalScript(original, eventTargetCallbackAccessor)
       )
       __proxy(win[o].prototype, 'removeEventListener', original =>
-        __traceOriginalScript(original, eventTargetCallbackAccessor)
+        __traceOriginalScript(original, eventTargetCallbackAccessor, true)
       )
     })
 
-    function __traceOriginalScript (fn, callbackAccessor) {
+    function __traceOriginalScript (fn, callbackAccessor, alsoCallOriginal = false) {
       return function () {
-        var args = Array.prototype.slice.call(arguments)
-        var cba = callbackAccessor(args)
-        var cb = cba.get()
+        // this is required for removeEventListener to remove anything added with
+        // addEventListener before the functions started being wrapped by Bugsnag
+        const args = Array.prototype.slice.call(arguments)
+        const cba = callbackAccessor(args)
+        const cb = cba.get()
+        if (alsoCallOriginal) fn.apply(this, args)
         if (typeof cb !== 'function') return fn.apply(this, args)
         try {
           if (cb.__trace__) {

packages/plugin-inline-script-content/test/inline-script-content.test.js

@@ -190,4 +190,45 @@ Lorem ipsum dolor sit amet.
     expect(payloads[0].events[0].stacktrace).toEqual([])
     expect(spy).toHaveBeenCalledTimes(0)
   })
+
+  it('calls removeEventListener with wrapped and unwrapped callback', () => {
+    const scriptContent = `console.log("unwrapped")`
+    const document = {
+      scripts: [ { innerHTML: scriptContent } ],
+      currentScript: { innerHTML: scriptContent },
+      documentElement: {
+        outerHTML: `<p>
+Lorem ipsum dolor sit amet.
+Lorem ipsum dolor sit amet.
+Lorem ipsum dolor sit amet.
+</p>
+<script>${scriptContent}
+</script>
+<p>more content</p>`
+      }
+    }
+    function Window () {}
+    Window.prototype = {
+      addEventListener: function () {},
+      removeEventListener: function () {}
+    }
+    const window = {
+      location: { href: 'https://app.bugsnag.com/errors' }
+    }
+
+    Object.setPrototypeOf(window, Window.prototype)
+    window.Window = Window
+
+    function myfun () {}
+    window.addEventListener('click', myfun)
+
+    const spy = spyOn(Window.prototype, 'removeEventListener')
+    const client = new Client(VALID_NOTIFIER)
+    client.setOptions({ apiKey: 'API_KEY_YEAH' })
+    client.configure()
+    client.use(plugin, document, window)
+
+    window.removeEventListener('click', myfun)
+    expect(spy).toHaveBeenCalledTimes(2)
+  })
 })