bulk-decaffeinate/jscodeshift-scripts-dist/top-level-this-to-exports.js

Run decaffeinate and related operations on a whole codebase, or just part of one.

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = transformer;
/**
 * jscodeshift script that converts top-level `this` usages to explicitly be the
 * `exports` identifier, which is the meaning of top-level `this` for node.
 */
function transformer(file, api) {
  var j = api.jscodeshift;

  return j(file.source).find(j.ThisExpression).forEach(function (path) {
    if (isAtTopLevel(path)) {
      j(path).replaceWith(j.identifier('exports'));
    }
  }).toSource();
}

function isAtTopLevel(thisPath) {
  var path = thisPath;
  while (path) {
    var type = path.node.type;
    // Check the node name to see if this ancestor defines a meaning to `this`.
    // Doing string matching on the name is sort of hacky, but this check works
    // with all parsers that I'm aware of and makes it less likely that we
    // missed a case like async functions.
    if ((type.includes('Function') || type.includes('Method')) && !type.includes('ArrowFunction')) {
      return false;
    }
    path = path.parentPath;
  }
  return true;
}