create-react-app can't minify parser.js

[tomclark]

Hi there,

Having a problem with the library building from create-react-app from v3.0.0 onwards. 2.12.1 is fine. On running npm run build, I get:

> react-scripts build

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

Failed to minify the code from this file:

 	./node_modules/rss-parser/lib/parser.js:16

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

Looks like an ES5/ES6 issue?

[rbren]

Thanks for the report. We did switch to ES6 in 3.0.0

From the bit.ly link, it says "ask that the package be published pre-compiled". We have a pre-compiled version in dist/rss-parser.min.js. Are you able to import that file?

[tomclark]

Was in a bit of a hurry, so I just downgraded to 2.12.1 which works absolutely fine and got me moving.

Will have a go at importing the file directly when I get a chance at the weekend and report back.

Thanks for the quick reply! 👍

[nikomc0]

I've got a noob question. Im not quite sure exactly how to properly import the min version.

[tomclark]

What client technology are you using?

At the root of the project, run:

npm install --save rss-parser

It's then in node_modules/rss-parser/dist/rss-parser.min.js.

How and where you include that in your pages then depends what client framework you're using (i.e.React, Angular etc).

[nikomc0]

Im using react and getting "Parser is not a constructor" error.

[rbren]

It should be new RSSParser()

[n7best]

@nikomc0 encounter the same issue while using create-react-app.

What I did to solve around is to import the pre-compiled version directly and use the RSSParser instead of Parse and I also have to declare eslint global namespace to avoid the create-react-app build errors.

/* global RSSParser */
import 'rss-parser/dist/rss-parser.min.js';

let parser = new RSSParser();

also, I tried to add module property to the package.json which pass the build but since two version has different parser naming, it wasn't working properly.

[rbren]

Thanks @n7best. Any tips on how we can change rss-parser to better support create-react-app?

[JochenFromm]

Had the same issue for a Travis CI integration of an app created with create-react-app. The Travis log says

> react-scripts build
Creating an optimized production build...
Failed to compile.
Failed to minify the code from this file: 
 	./node_modules/rss-parser/lib/parser.js:16 

The create-react-app README argues the package should be published pre-compiled to ES5 (not ES6).

[rbren]

I tried switching to babel-preset-env, but it gives the same result as babel-preset-2015

The code generated by babel (everything in ./dist/) is all ES5, per the README. So I'm not sure what the problem might be.

[Locheed]

Any news about a solution for this? Just noticed the same problem and came searching some answers.

[Locheed]

Yea CRA doesn't seem to transpile external dependencies to ES5. It has to be precompiled. https://github.com/facebook/create-react-app/issues/1125

workaround from @n7best works fine now.

[Ueland]

Jumping in on this thread after noticing the same issue, will use the workaround for now.

[gazpachu]

I will also use the workaround for now

[cgpomeroy]

Can someone explain further how to implement @n7best 's workaround? I've tried the below with no success.

[415DomSmith]

@cgpomeroy

I was able to implement in my create-react-app.

I'm using Axios to fetch the page data.

const RSSParser = require('rss-parser');

getWiredFeed(){
    axios.get('https://www.wired.com/feed')
    .then((res) => {
      let parser = new RSSParser();
      parser.parseString(res.data, (err, feed)=> {
        this.setState({
          wiredItems: feed.items
        });
      });
    })
    .catch((err) => {
      console.log(err);
    })
  }

[udeshx]

Using the suggestion from @415DomSmith I got the example to work without the need for axios

const RSSParser = require('rss-parser');
const CORS_PROXY = "https://cors-anywhere.herokuapp.com/"

let parser = new RSSParser();
parser.parseURL(CORS_PROXY + 'https://www.reddit.com/.rss', function(err, feed) {
  console.log(feed.title);
  feed.items.forEach(function(entry) {
    console.log(entry.title + ':' + entry.link);
  })
})

[ranpox]

@cgpomeroy Hi, have you found the way to solve it? Workaround from @n7best doesn't work for me.

[antoinedelp]

Hi @bobby-brennan, thanks for your great RSS Parser. Everything works fine in development, but I get the same "Failed to minify the code from this file: ./node_modules/rss-parser/lib/parser.js:16" error message when building my project.

The workaround (importying the minified version) is not working as I get this error message : RSSParser() is not a constructor.

By any chance, did you manage to identify what the issue is, or at least do you recommend a specific workaround to solve this issue? Thanks!

[rbren]

I would try using the file in dist/rss-parser.min.js. If you're using version 2.x, you should also use the README from that version, as the API has changed. In particular, RSSParser is not a constructor in 2.x - instead, you use RSSParser.parseUrl(...)

[anshulsinha1101]

@nikomc0 encounter the same issue while using create-react-app.

What I did to solve around is to import the pre-compiled version directly and use the RSSParser instead of Parse and I also have to declare eslint global namespace to avoid the create-react-app build errors.

/* global RSSParser */
import 'rss-parser/dist/rss-parser.min.js';

let parser = new RSSParser();

also, I tried to add module property to the package.json which pass the build but since two version has different parser naming, it wasn't working properly.

If i am using Your method i am getting a compile time error of

TS2304: Cannot find name 'RSSParser'

please help me to resolve this

[JohnnyHandy]

@415DomSmith solution worked for me! The only difference is that I had to use the cors proxy.