replaceShorthandObjectMethod.js 2.71 KB
"use strict";

exports.__esModule = true;
exports.default = replaceShorthandObjectMethod;

var _babelTypes = require("babel-types");

var t = _interopRequireWildcard(_babelTypes);

var _util = require("./util");

var util = _interopRequireWildcard(_util);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

// this function converts a shorthand object generator method into a normal
// (non-shorthand) object property which is a generator function expression. for
// example, this:
//
//  var foo = {
//    *bar(baz) { return 5; }
//  }
//
// should be replaced with:
//
//  var foo = {
//    bar: function*(baz) { return 5; }
//  }
//
// to do this, it clones the parameter array and the body of the object generator
// method into a new FunctionExpression.
//
// this method can be passed any Function AST node path, and it will return
// either:
//   a) the path that was passed in (iff the path did not need to be replaced) or
//   b) the path of the new FunctionExpression that was created as a replacement
//     (iff the path did need to be replaced)
//
// In either case, though, the caller can count on the fact that the return value
// is a Function AST node path.
//
// If this function is called with an AST node path that is not a Function (or with an
// argument that isn't an AST node path), it will throw an error.
function replaceShorthandObjectMethod(path) {
  if (!path.node || !t.isFunction(path.node)) {
    throw new Error("replaceShorthandObjectMethod can only be called on Function AST node paths.");
  }

  // this function only replaces shorthand object methods (called ObjectMethod
  // in Babel-speak).
  if (!t.isObjectMethod(path.node)) {
    return path;
  }

  // this function only replaces generators.
  if (!path.node.generator) {
    return path;
  }

  var parameters = path.node.params.map(function (param) {
    return t.cloneDeep(param);
  });

  var functionExpression = t.functionExpression(null, // id
  parameters, // params
  t.cloneDeep(path.node.body), // body
  path.node.generator, path.node.async);

  util.replaceWithOrRemove(path, t.objectProperty(t.cloneDeep(path.node.key), // key
  functionExpression, //value
  path.node.computed, // computed
  false // shorthand
  ));

  // path now refers to the ObjectProperty AST node path, but we want to return a
  // Function AST node path for the function expression we created. we know that
  // the FunctionExpression we just created is the value of the ObjectProperty,
  // so return the "value" path off of this path.
  return path.get("value");
}