build-schema.js

const {basename, dirname, join} = require('path');
const glob = require('glob');
const yargs = require('yargs/yargs');
const {hideBin} = require('yargs/helpers');
const merge = require('lodash/merge');
const fs = require('fs');

const argv = yargs(hideBin(process.argv)).argv;

function buildSchema(from, to) {
  const schemas = glob.sync(from);

  schemas.forEach((schemaPath) => {
    const builder = basename(dirname(schemaPath));
    const schema = loadSchema(schemaPath);
    const schemaName = basename(schemaPath);
    const originalSchema = loadSchema(
      `./node_modules/@angular-devkit/build-angular/src/builders/${builder}/schema.json`,
    );
    const newSchema = merge(originalSchema, schema);
    const newSchemaPath = join(to, builder, schemaName);

    fs.writeFileSync(newSchemaPath, JSON.stringify(newSchema, null, 2), 'utf-8');
  });
}

function loadSchema(path) {
  return JSON.parse(fs.readFileSync(path, {encoding: 'utf-8'}));
}

if (argv.from && argv.to) {
  buildSchema(argv.from, argv.to);
}

module.exports = {buildSchema};