error when minifying code

[gabririgo]

react gives me this error:

Failed to minify the code from this file:

./node_modules/@parity/api/format/output.js:19 

Read more here: http://bit.ly/2tRViJ9

From the link:

npm run build fails to minify

You may occasionally find a package you depend on needs compiled or ships code for a non-browser environment.
This is considered poor practice in the ecosystem and does not have an escape hatch in Create React App.

To resolve this:

Open an issue on the dependency's issue tracker and ask that the package be published pre-compiled (retaining ES6 Modules).
Fork the package and publish a corrected version yourself.
If the dependency is small enough, copy it to your src/ folder and treat it as application code.

[jacogr]

We are using from this repo in a React/Webpack environment without issues, along with Uglify.

Could you post the full failure log? (Line 19 is a require from another package, so not 100% sure where/why, would need to investigate and see how we can squash it)

[gabririgo]

sure will do and come back, using parity/parity.js and using transport instead of provider it does not give any error

[jacogr]

Will also create a scaled-down version using react-create-app - should help in debugging the issue.

[jacogr]

Ok, can reproduce -

test-js-api$ npm run build                          

> test-js-api@0.1.0 build /Users/jacogreeff/Projects/ethcore/test-js-api
> react-scripts build

Creating an optimized production build...
Failed to compile.

Failed to minify the code from this file: 

 	./node_modules/@parity/api/format/output.js:19 

[gabririgo]

yes that is the error prompted when using using yarn build in react-create-app!

[jacogr]

Ok, this is due to react-create-app not operating on node_modules and has no real way of overriding this. Although the target browsers, those supporting fetch (& node) supports arrow functions and const { xyz } = abc deconstructions, the build does not since it is looking for a lower common.

facebook/create-react-app#1125

As per the above, we are not the only ones with this slight issue. Leaving it open to try and find a solution that does not involve re-wiring everything pre arrow-functions and deconstruction and also does not require bringing back the pre-compilation step.

[jacogr]

@parity/api version 2.1.1+ should solve the issue, the explicit ES5 version is now published to npm.

[gaearon]

FYI, we're starting the work to compile deps with babel-preset-env in Create React App: facebook/create-react-app#3776

Let us know if you have feedback about how this should work.