RollupJS error on file util/isArrayLike.js

[noemi-salaun]

RxJS version:
5.2.0

Code to reproduce:
Run RollupJS in a project that uses RxJS.
Use rollup plugin rollup-plugin-commonjs with config

plugins  : [
        commonjs({
            include     : [
                'node_modules/rxjs/**'
            ]
        }
]

Expected behavior:
Bundling with RollupJS should work

Actual behavior:

Error: Unexpected token
node_modules/rxjs/util/isArrayLike.js (2:78)
1: "use strict";
2: var isArrayLike_1 = function (x) { return x && typeof x.length === 'number'; });
                                                                                 ^
3: //# sourceMappingURL=isArrayLike.js.map

Additional information:
Just removing the parenthesis works for me.

Replace :

exports.isArrayLike = (function (x) { return x && typeof x.length === 'number'; });

with :

exports.isArrayLike = function (x) { return x && typeof x.length === 'number'; };

[kwonoj]

So this seems like isArrayLike is wrapped with parenthesis
export const isArrayLike = (<T>(x: any): x is ArrayLike<T> => x && typeof x.length === 'number');,

but it brings curiousity if it doesn't work with any other codes like this - @noemi-salaun , would you able to try out cjs equivalent such as

const isArrayLike = ((x) => x && typeof x.length === 'number');

and given rollup-plugin-commonjs can consume those as well?

[noemi-salaun]

I tried with isArrayLike.js looking like :

"use strict";
exports.isArrayLike = ((x) => x && typeof x.length === 'number');
//# sourceMappingURL=isArrayLike.js.map

but it's the same error

Error: Unexpected token
node_modules/rxjs/util/isArrayLike.js (2:60)
1: "use strict";
2: var isArrayLike_1 = (x) => x && typeof x.length === 'number');
                                                               ^
3: //# sourceMappingURL=isArrayLike.js.map

But it seems that rollup-plugin-commonjs can handle it.

So I tried without parenthesis :

"use strict";
exports.isArrayLike = (x) => x && typeof x.length === 'number';
//# sourceMappingURL=isArrayLike.js.map

It works but rollup-plugin-uglify does not like it

Error: (uglify plugin) Error transforming bundle with 'uglify' plugin: SyntaxError: Unexpected token: operator (>)

[kwonoj]

Hm, seems my PR is premature and probably won't work as workaround.

I'm feeling this is more like rollup side issues, since given module is simple function export and should be able to be consumed. Does rollup confirms it's expected behavior on rollup side? If not, I'd like to suggest check with rollup as well. I assume given error can be reproducible without depends on Rx.

[noemi-salaun]

Hm no, I didn't check with rollup people.

I will ask them to see if the issue come from there side.

Thank you for the fast reply 😄

[noemi-salaun]

Hu, someone already takes care of it.

rollup/rollup-plugin-commonjs#168

[kwonoj]

@noemi-salaun Cool. Let me close this issue for now, feel freely reopen once rollup clarifies if it isn't related with rollup's behavior but need RxJS side code changes.

[blagerweij]

This is not a rollup bug, but rxjs. Reverting to version 5.1.1 of rxjs fixes it, since 5.2.0 the problem exists. If you remove the round brackets, it's also fine. Right now this issue is closed, as well as the rollup issue (#168). I suggest this is fixed in rxjs, please re-open the issue and remove the round brackets in isArrayLike function.

[noemi-salaun]

There isn't the issue with rxjs 5.1.1 because there isn't the file util/isArrayLike.js before version 5.2.0.
The parenthesis aren't the problem, it's the way rollup-plugin-commonjs parse it.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.