devtool: 'eval' causes ReferenceError

[gaearon]

I tried switching to devtool: 'eval' but I keep getting ReferenceErrors in one of the files.
The code is perfectly legit though and works fine with devtool: 'source-map'.

Offending code is from Facebook Flux Dispatcher:

  Dispatcher.prototype.register=function(callback) {"use strict";
    var id = _prefix + _lastID++; // <- Uncaught ReferenceError: _prefix is not defined 
    this.$Dispatcher_callbacks[id] = callback;
    return id;
  };

This variable is declared on top of that file:

var _prefix = 'ID_';

Dispatcher.js

[gaearon]

Weirder, this seems to only affect Chrome and doesn't happen when "use strict" is removed from function.

[gaearon]

This may actually be a Chrome bug.

This fiddle alerts OK in all browsers except Chrome.

[jhnns]

It's not a webpack problem, it's caused by the scoped use of "use strict". I've described the problem at a pull-request for FastClick.

[gaearon]

I'm curious: why does this work in other browsers? Do they implement the spec incorrectly?

[jhnns]

Yes ... you're right, it's strange. I don't know.

[balanceiskey]

I've opened a PR with the Flux folks that references this: facebookarchive/flux#45

[sophiebits]

This behavior may match the spec for eval, but it's still unintuitive (and IMO, a bug) that the recommended devtool setting for source maps causes code to behave differently than it does without the source map.

[aaronjensen]

@gaearon were you able to get this working? Even w/ flux 2.0.1 I still see the error when using eval

[aaronjensen]

@gaearon I got it fixed by using "react-router": "rackt/react-router" because remix-run/react-router#280 has not been released yet