Mobx: Release 3.1.6 breaks build with error 'Cannot set property 'default' of undefined'

[w-]

1. [ x] Issue:
   
   
   
   • [x ] Provide error messages including stacktrace
   
   
   • [ ] Provide as much relevant code, or, preferrably **create a reproduction based on this [JSFiddle]
   
   

Here's a quick stack trace

Uncaught TypeError: Cannot set property 'default' of undefined
    at Object.<anonymous> (mobx.js:50)
    at Object../node_modules/mobx/lib/es2015/mobx.js (mobx.js:2830)
    at __webpack_require__ (bootstrap c57644c…:691)
    at fn (bootstrap c57644c…:110)
    at Object.7 (vendors.bundle.c57644c….js:55622)
    at __webpack_require__ (bootstrap c57644c…:691)
    at ./node_modules/add-px-to-style/index.js.IS_UNITLESS.animationIterationCount (bootstrap c57644c…:786)
    at bootstrap c57644c…:786

The line with issue appears to be the very last line in this code block.
Is this related to #858 ?

registerGlobals();
export { Atom, BaseAtom };
export { Reaction };
export { untracked, IDerivationState };
export { useStrict, isStrictModeEnabled };
export { spy };
export { asReference, asFlat, asStructure, asMap };
export { isModifierDescriptor };
export { isObservableObject };
export { isObservableValue as isBoxedObservable };
export { isObservableArray };
export { ObservableMap, isObservableMap, map };
export { transaction };
export { observable, IObservableFactories };
export { computed };
export { isObservable };
export { isComputed };
export { extendObservable, extendShallowObservable };
export { observe };
export { intercept };
export { autorun, autorunAsync, when, reaction };
export { action, isAction, runInAction };
export { expr };
export { toJS };
export { createTransformer };
export { whyRun };
export { isArrayLike };
export const extras = {
    allowStateChanges,
    deepEqual,
    getAtom,
    getDebugName,
    getDependencyTree,
    getAdministration,
    getGlobalState,
    getObserverTree,
    isComputingDerivation,
    isSpyEnabled,
    onReactionError,
    resetGlobalState,
    shareGlobalState,
    spyReport,
    spyReportEnd,
    spyReportStart,
    setReactionScheduler
};
if (typeof __MOBX_DEVTOOLS_GLOBAL_HOOK__ === "object") {
    __MOBX_DEVTOOLS_GLOBAL_HOOK__.injectMobx(module.exports);
}
module.exports.default = module.exports;

• [x ] Did you check this issue wasn't filed before?

• [x ] Elaborate on your issue. What behavior did you expect?
  I expected my build not to break

• [x ] State the versions of MobX and relevant libraries. Which browser / node / ... version?
  webpack: 2.2.1
  mobx 3.1.6
  mobx-react 4.1.6

I'm fairly certain nothing else is the issue because if i downgrade mobx to the last known good combo i had:
mobx 3.1.2
mobx-react 4.1.1

Build works as expected again.

[mweststrate]

Could you try [email protected] ?

[timurrustamov]

Same issue here!

But works fine with [email protected] and downwards, maybe module var is overwritten in 3.1.6?

[mweststrate]

Probably webpack 2 prefers the es2015 build, but for es6 modules doesn't provide the module.exports stuff which is used only to simulate

[w-]

@mweststrate some progress. different error now.

Uncaught TypeError: Cannot set property 'struct' of undefined
    at Object.<anonymous> (mobx.js:516)
    at Object.<anonymous> (mobx.js:2832)
    at __webpack_require__ (bootstrap 048f392…:52)
    at Object.<anonymous> (harmony-module.js:24)
    at __webpack_require__ (bootstrap 048f392…:52)
    at bootstrap 048f392…:144
    at bootstrap 048f392…:144

happens here:

observable.deep.struct = observable.struct;

in this block of code:

var observable = createObservable;
Object.keys(IObservableFactories.prototype).forEach(key => observable[key] = IObservableFactories.prototype[key]);
observable.deep.struct = observable.struct;
observable.ref.struct = function () {
    if (arguments.length < 2) {
        return createModifierDescriptor(refStructEnhancer, arguments[0]);
    }
    else {
        return refStructDecorator.apply(null, arguments);
    }
};

In case it makes a difference, I'm totally ok with chilling on 3.1.2 until this gets sorted.

thanks for all your efforts on the library!

[mweststrate]

cc: @mohsen1 @capaj

[mweststrate]

@mohsen1 probably stuff works better if we don't use the concatened files in the build (which are stripped further down), but just do a simple build like quickbuild. Downside is that that makes the build much bigger (and a bit slower), but hopefully tree shaking makes up for that :)

[AviVahl]

@mweststrate please note v3.1.6 somehow got unpublished when you released 3.1.6-fix887.
This broke stuff on our end, as we use exact versions in deps.
Could you please release 3.1.7 to fix this?

See:
https://www.npmjs.com/package/mobx
3.1.6-fix887 is the latest of 72 releases

[mweststrate]

@AviVahl Released 3.1.7, containing all the changes from 3.1.6 except the es2015 modules