MiddlewareStack duplicate handler issue on Microsoft Edge & Chrome Canary

[nathan-muir]

@tmeasday Not sure if you're still maintaining this. This is kind of related to #986 which you commented on. Also relates to #1270, and #1328.

This example now fails in the Microsoft Edge browser. (& Also in Chrome Canary w/ Experimental Javascript On.)

Why:
Because MiddlewareStack does some funky things with function names and uniqueness.

In Microsoft Edge, we now have new behaviour with function names & object literals:

var myObj = {
  // Note, function is anonymous.
  onBeforeAction: function() {} 
};
console.log(myObj.onBeforeAction.name)
// in Chrome/Firefox: ""
// in Edge: "onBeforeAction"
// in Chrome Canary + Experimental Javascript: "onBeforeAction"

That's right, anonymous functions now get names in object literals, even without using es6 object syntax.

How:

1. Because MiddlewareStack._create enforces a 'unique' mapping of Handler's names.
2. Handler automatically "picks" a name for any-named function

Proposed Solution:

I can't find any code in iron-router that even uses any of the name-related API's. (findByName, insertBefore and insertAfter).

So there are really two options:

1. Add some option / flag / type that bypasses names in MiddlewareStack. (Maintaining existing API's if someone is using it?)
2. Just remove anything name related from MiddlewareStack, and bump a major version. Pull Request

[MiroHibler]

I can confirm this is also happening in the latest version of Chrome Canary (currently v50.0.2653.0 but it started in v50.0.2651.0 I believe).

[nathan-muir]

Thanks @MiroHibler, I could reproduce in Chrome Canary too, but only after enabling "
Experimental Javascript" in chrome://flags/#enable-javascript-harmony

[chrisbutler]

@nathan-muir is this definitely the fix? iron-meteor/iron-middleware-stack#8

[nathan-muir]

@chrisbutler It's a fix (I've currently deployed for my apps);

Use at your own discretion, iron-router is a bit of a tangle though (to me), so I'm hoping to get someone more knowledgeable to review.

[tmeasday]

Hi @nathan-muir -- I am not maintaining IR at this point. I'm not sure what the current status of maintenance is. @cmather?

[sylido]

I can verify this behavior on Version 51.0.2669.0 canary (64-bit) without touching the default setting for Experimental Javascript (disabled). Removing the second onBeforeAction hook fixes the problem.

[lorensr]

Looks related: #1520

I do have multiple global onBeforeActions, if that's the problem

[nathan-muir]

@lorensr yeah, that would be it

[noosphere2]

Receiving this error in Chrome canary 51.0.2673.0:

middleware_stack.js:31 Uncaught Error: Handler with name 'route' already exists.

From a simple:

Router.route('/aroute', function() {});

Until @nathan-muir's code is reviewed and pulled into main repo, the error can be subdued by forcing each route to be named:

Router.route('/aroute', {name: 'aroute'}, function() {});

[maxfi]

Thanks @Zlot. That's fixed it for me on Chrome Canary 51.0.2673.0 (64-bit) as well.

[tmeasday]

Fixed: meteor update iron:middleware-stack.

[markreid]

I understand there's a resolution for this but it may be worth noting that it's impacting Chrome 51.x which is now stable.

[brewhk-dev]

Running meteor update iron:middleware-stack didn't work for us. Instead, we had to ensure all routes are named - that fixed it.

[tmeasday]

@brewhk-dev what version of I:ms did you end up with?

[tmeasday]

I suspect I need to do a release of iron router that explicitly depends on this fixed version.

[brewhk-dev]

Our app is running on METEOR@1.1.0.2, with the follow iron:* versions:

iron:controller@1.0.8
iron:core@1.0.11
iron:dynamic-template@1.0.8
iron:layout@1.0.8
iron:location@1.0.9
iron:middleware-stack@1.1.0
iron:router@1.0.9
iron:url@1.0.11

Chrome version - 51.0.2704.84 (64-bit)

But simply updating the package didn't work for us, we had to make sure the routes are named.

[tmeasday]

@brewhk-dev --- that is very surprising to me. Can you provide a simple reproduction of the problem?

[tmeasday]

Ok, released iron:router@1.0.13

[levino]

Wont fix withiron:router@1.0.13 And I cannot use names easily as I have multiple "onBeforeActions". How would I give names to the routes then?

[tmeasday]

Wont fix withiron:router@1.0.13

What does that mean?

I don't understand how naming routes could fix this problem if it still occurs with that version. It removed code that looks at names.

[levino]

Edit: Removing this. Error on my side. Fix looks good.

[wbashir]

@tmeasday I tried adding this fix but with my Meteor version 1.1.0.2 I am running into an issue adding dependency packages.

$ meteor add iron:router@1.0.13
 => Errors while adding packages:             

While selecting package versions:
error: unknown package: isobuild:isopack-2
Required by: iron:dynamic-template 1.0.12
Required by: iron:layout 1.0.12
Required by: iron:router 1.0.13
Required by: iron:router 1.0.13

Any ideas?

[tmeasday]

Looks like you may be on an old version of Meteor?

[CarlQLange]

Yep, updating middleware-stack worked for me. Nice job @tmeasday and all IR contributors :)

[martriay]

Just like @brewhk-dev, naming the routes worked for me while updating didn't

[wbashir]

@tmeasday I am indeed on an older version of Meteor and ended up updating the middleware-stack