.abi.js

var fs = require('fs');
var path = require('path');

const OUTPUT_DIR = process.env.OUTPUT || './build/abi/';

if (!fs.existsSync(OUTPUT_DIR)) {
  fs.mkdirSync(OUTPUT_DIR);
}

function readFiles(dirname, onFileContent, onError) {
  fs.readdir(dirname, function(err, filenames) {
    if (err) {
      onError(err);
      return;
    }
    filenames.forEach(function(filename) {
      fs.readFile(dirname + filename, 'utf-8', function(err, content) {
        if (err) {
          onError(err);
          return;
        }
        onFileContent(filename, content);
      });
    });
  });
}

let dir = './build/contracts/';
readFiles(dir, function(filename, content) {
  if (filename.includes(".abi.")) return;
  let abi = JSON.stringify(JSON.parse(content).abi, null, 2);
  fs.writeFileSync(`${OUTPUT_DIR}${path.basename(filename, '.json')}.abi.json`, abi);
}, function(err) {
  throw err;
});