babel-core/lib/babel/transformation/transformers/es6/spec.block-scoping.js

Turn ES6 code into readable vanilla ES5 with source maps

"use strict";

var _interopRequireWildcard = function (obj) { return obj && obj.__esModule ? obj : { "default": obj }; };

exports.BlockStatement = BlockStatement;
exports.__esModule = true;

var t = _interopRequireWildcard(require("../../../types"));

var visitor = {
  enter: function enter(node, parent, scope, state) {
    if (!this.isReferencedIdentifier()) return;
    if (t.isFor(parent) && parent.left === node) return;

    var declared = state.letRefs[node.name];
    if (!declared) return;

    // declared node is different in this scope
    if (scope.getBindingIdentifier(node.name) !== declared) return;

    var assert = t.callExpression(state.file.addHelper("temporal-assert-defined"), [node, t.literal(node.name), state.file.addHelper("temporal-undefined")]);

    this.skip();

    if (t.isAssignmentExpression(parent) || t.isUpdateExpression(parent)) {
      if (parent._ignoreBlockScopingTDZ) return;
      this.parentPath.replaceWith(t.sequenceExpression([assert, parent]));
    } else {
      return t.logicalExpression("&&", assert, node);
    }
  }
};

var metadata = {
  optional: true
};

exports.metadata = metadata;

function BlockStatement(node, parent, scope, file) {
  var letRefs = node._letReferences;
  if (!letRefs) return;

  this.traverse(visitor, {
    letRefs: letRefs,
    file: file
  });
}

exports.Program = BlockStatement;
exports.Loop = BlockStatement;