babel-core/lib/babel/transformation/transformer-pass.js

Turn ES6 code into readable vanilla ES5 with source maps

module.exports = TransformerPass;

var includes = require("lodash/collection/includes");

/**
 * This class is responsible for traversing over the provided `File`s
 * AST and running it's parent transformers handlers over it.
 */

function TransformerPass(file, transformer) {
  this.transformer = transformer;
  this.shouldRun   = !transformer.check;
  this.handlers    = transformer.handlers;
  this.file        = file;
}

TransformerPass.prototype.canRun = function () {
  var transformer = this.transformer;

  var opts = this.file.opts;
  var key  = transformer.key;

  // internal
  if (key[0] === "_") return true;

  // blacklist
  var blacklist = opts.blacklist;
  if (blacklist.length && includes(blacklist, key)) return false;

  // whitelist
  var whitelist = opts.whitelist;
  if (whitelist.length) return includes(whitelist, key);

  // optional
  if (transformer.optional && !includes(opts.optional, key)) return false;

  // experimental
  if (transformer.experimental && !opts.experimental) return false;

  // playground
  if (transformer.playground && !opts.playground) return false;

  return true;
};

TransformerPass.prototype.checkNode = function (node) {
  var check = this.transformer.check;
  if (check) {
    return this.shouldRun = check(node);
  } else {
    return true;
  }
};

TransformerPass.prototype.transform = function () {
  if (!this.shouldRun) return;

  var file = this.file;

  file.debug("Running transformer " + this.transformer.key);

  file.scope.traverse(file.ast, this.handlers, file);
};