Class Transformers

cli/transformers.js:4–81

const fs = require('fs');

class Transformers {

  constructor (env, stdlib, environment) {
    this.env = env;
    this.stdlib = stdlib;
    this.environment = environment;
    this.list = [];
    this.load();
  }

  load () {
    let stdlib = this.stdlib;
    let transformers = [];
    if (stdlib.transformers) {
      if (!Array.isArray(stdlib.transformers)) {
        throw new Error(`"stdlib.json": "transformers" must be an array`);
      }
      transformers = stdlib.transformers.map(transformerData => {
        let Transformer;
        let transformer;
        if (!transformerData.pathname) {
          throw new Error(`"stdlib.json": "transformers" object must contain "pathname"`);
        }
        try {
          Transformer = require(path.join(process.cwd(), transformerData.pathname));
          let config = transformerData.config || {};
          if (!config || typeof config !== 'object') {
            throw new Error(`"stdlib.json": "transformers[].config" must be empty or contain an object`);
          }
          let configEnv = config[this.environment] || {};
          if (!config[this.environment] || typeof config[this.environment] !== 'object') {
            throw new Error(`"stdlib.json": "transformers[].config['${this.environment}']" must be empty or contain an object`);
          }
          transformer = new Transformer(config[this.environment], stdlib, this.environment);
          transformer.config = transformerData.config[this.environment];
        } catch (e) {
          console.error(e);
          throw new Error(`Could not load transformer: "${transformerData.pathname}"`);
        }
        return transformer;
      });
    }
    return this.list = transformers;
  }

  async compile () {
    let preloadFiles = {};
    let metadata = {};
    for (let i = 0; i < this.list.length; i++) {
      let transformer = this.list[i];
      let name = transformer.name || transformer.constructor.name;
      let t = new Date().valueOf();
      console.log(`\n[Transformer: ${name}] Execution starting`);
      console.log(
        `[Transformer: ${name}] Using config from stdlib.json: ` +
        `transformers[].config['${this.environment}']\n` +
        `${JSON.stringify(transformer.config, null, 2)}`
      );