Thanks for the fix !
I'll test this in the context of Angular before merging.

Maybe.

If we change the target to this || self, then obviously we'll be invoking it with a target of self when this is falsy. I have no idea how all the browsers normally behave when you invoke these functions with a falsy target (is it specced?). The current solution seems somewhat 'safer' in that the self path is only taken on web workers.

What do you think?

When would this be falsy ? (outside of a web worker)

@vicb

In 'working' code? I have no idea. But if someone does, in development, the following:

'use strict';

var fn = eventTarget.addEventListener;
fn('click', function () {});  

Then shouldn't the behaviour be the same (or as close as possible) whether zone is loaded or not?

Not sure I get your point here, wouldn't you write fn.call(eventTarget, 'click', function); above ?

You would, yes. But my point was, that if a developer when writing their app mistakenly writes:

'use strict';

var fn = eventTarget.addEventListener;
fn('click', function () {});  

Then the code should error out (or nor as the case may be) whether zone is loaded or not. Basically, the behaviour should be consistent for zone and non-zone code, even if that behaviour is an error. In this case, one would presume that this would be falsy inside the addEventListener implementation, and the code should run as such.

That makes sense.

It seems like Travis testing Angular with this is happy (currently re-running a failed test but looks like a glitch). Once it's green, I'll merge the PR. Thanks !

landed as ad5c0c8