Investigate running NodeJS / Express locally

[tuukka]

This would help e.g. running Digitransit UI locally.

[0is1]

Well, there's some hacks that try to enable node.js core modules and their dependencies in RN see: https://github.com/mvayngrib/rn-nodeify or https://github.com/philikon/ReactNativify

But there are limitations and concerns like

• rn-nodeify won't work with modules that are added using npm link
• rn-nodeify is scary because it recurses down node_modules and modifies all the package.json's in there to add/update the browser and react-native (not to mention pkg-hacks)
• rn-nodeify requires a lot of hassle
  • modules that contain a .babelrc will cause problems with the latest react-native version (0.20 at this time), remove them after installation (rm node_modules/*/.babelrc)
  • when installing a package from git, the postinstall hook isn't triggered, run it manually instead (npm run postinstall)
  • restart the react-native packager after installing a module!
• npm3 is required in ReactNativify (or yarn install --flat)
• Both of these seems to be unstable when it comes to RN updates and/or dealing with the React Native packager
  • https://github.com/mvayngrib/rn-nodeify/issues/18
  • https://github.com/mvayngrib/rn-nodeify/issues/27
  • Breaking with latest react-native v0.43.3 philikon/ReactNativify#6
  • Buffer is not defined philikon/ReactNativify#5
• ReactNativify crypto and bitcoin examples are really slow, it takes over 5sec to execute this kind of code:

  const keyPair = bitcoin.ECPair.fromWIF(
    'L1uyy5qTuGrVXrmrsvHWHgVzW9kKdrp27wBC7Vs6nZDTF2BRUVwy'
  );
  const tx = new bitcoin.TransactionBuilder();

  tx.addInput(
    'aa94ab02c182214f090e99a0d57021caffd0f195a81c24602b1028b130b63e31',
    0
  );
  tx.addOutput('1Gokm82v6DmtwKEB8AiVhm82hyFSsEvBDK', 15000);
  tx.sign(0, keyPair);

  const expected = '0100000001313eb630b128102b60241ca895f1d0ffca2170d5a0990e094f2182c102ab94aa000000006b483045022100aefbcf847900b01dd3e3debe054d3b6d03d715d50aea8525f5ea3396f168a1fb022013d181d05b15b90111808b22ef4f9ebe701caf2ab48db269691fdf4e9048f4f60121029f50f51d63b345039a290c94bffd3180c99ed659ff6ea6b1242bca47eb93b59fffffffff01983a0000000000001976a914ad618cf4333b3b248f9744e8e81db2964d0ae39788ac00000000';
  const actual = tx.build().toHex();

  return new Promise((resolve) => {
    process.nextTick(() => {
      resolve(actual === expected);
    });
  });

So I'm not so convinced about this approach.

And I'm not sure if it's even possible to run modules like express in RN, even in theory? Because for example http module is rewritten by https://github.com/jhiesey/stream-http and you don't obviously have there things like http.createServer (what you need with express) because RN runtime is basically Safari/Chrome browser.

[wswoodruff]

@0is1 Have you tried using babel-plugin-rewrite-require or babel-plugin-module-alias to let you require browserify Node package shims? Since babel is separate from react-native it seemed like the best solution to me. Here's and example with rewrite-require: philikon/ReactNativify#4 (comment)

and here's an example with module-alias: https://github.com/wswoodruff/strangeluv-native/blob/master/.babelrc

[wswoodruff]

As for running Express locally, not sure how that would benefit you guys.