/**
 * Transforms loop bodies and conditional branches to block statements.
 */
import {NodePath, VisitNode, Visitor} from 'babel-traverse';
import * as t from 'babel-types';

// Consequents and alternatives in if statements must always be blocked,
// otherwise variable declaration get pulled outside the branch.
const ifStatement : VisitNode<t.IfStatement> = function (path: NodePath<t.IfStatement>): void {
  const { consequent, alternate } = path.node;

  if (t.isBlockStatement(consequent) === false) {
    path.node.consequent = t.blockStatement([consequent]);
  }

  if (alternate !== null && t.isBlockStatement(alternate) === false) {
    path.node.alternate = t.blockStatement([alternate]);
  }
};

const loop: VisitNode<t.Loop> = function (path: NodePath<t.Loop>): void {
  if(t.isBlockStatement(path.node.body)) { return; }
  path.node.body = t.blockStatement([path.node.body]);
};

const visitor : Visitor = {
  IfStatement: ifStatement,
  "Loop": loop,
};

module.exports = function() {
  return { visitor: visitor };
};