error : ionc build ios or android, uglifyjs failed: SyntaxError: Unexpected token: operator (>)

[tianleios]

when i run ionic build ios. will display fllow errror，uglifyjs cannot support es6 feature arrow function
] ngc finished in 32.81 s
[19:52:49] bundle started ...
[19:53:01] bundle finished in 12.33 s
[19:53:01] uglifyjs started ...
[19:53:01] sass started ...
[19:53:02] uglifyjs failed: SyntaxError: Unexpected token: operator (>)
[19:53:02] ionic-app-script task: "build"
[19:53:02] Error: SyntaxError: Unexpected token: operator (>)

[jgw96]

Hello, thanks for opening an issue with us! uglifyJS does support arrow functions. Are you using the correct syntax for arrow functions? setTimeout(() => {});

[haxpor]

@jgw96 it happens the same for me with uglifyjs failed: SyntaxError: Unexpected token: operator (>). For my case, it's due to one of node modules I imported has es6 code, specifically arrow function. I tried not to import that module, and it passes, no error but not the other way around.

It seems uglifyJS has es6 support but in another branch harmony, once I tried hooking it up with gulp but failed. I don't know how to do it properly though.

Is it the case? If not, how to make this works with ionic 2.

Updated: I solved the problem now. As @jgw96 said that uglifyJS already supports es6, I just changed node_modules/@ionic/app-scripts/package.json file for uglify-js to git+https://github.com/mishoo/UglifyJS2.git#harmony. Then it automatically solves the problem. I now can build without error. For study, I will take a look at its code later on how the team did this as I failed before. Thanks.

[tianleios]

@haxpor can you display you resolve function detail

[tianleios]

@jgw96 i confirm i use correct arrow function

[haxpor]

@tianleios On your root project directory, edit node_modules/@ionic/app-scripts/package.json file. Then in that file update uglify-js like this "uglify-js": "git+https://github.com/mishoo/UglifyJS2.git#harmony".

Then after that execute npm install (make sure right now you're at node_modules/@ionic/app-scripts. Ignore error that shown. I have shown error about jasmine's build for path variable that it seems like it need src, but it works at the end.

[zhang-z]

@haxpor , the 'harmony' solution is working, thank you!

[jgw96]

This issue was moved to ionic-team/ionic-app-scripts#239

[jgw96]

Hello, thanks for using Ionic! Since this is a build issue i have moved this issue to the app-scripts repo.