swiftParseIfStatement.js

const plugin = (instance) => {
  instance.extend('parseIfStatement', inner => function (node) {
    this.next();
    const isParenFree = this.match(tokenTypes.parenL);

    node.test = isParenFree
      ? this.parseExpression()
      : this.parseParenExpression();
    node.consequent = isParenFree
      ? this.parseBlock(false)
      : this.parseStatement(false);

    node.alternate = this.eat(tt._else) ? this.parseStatement(false) : null;

    return this.finishNode(node, "IfStatement");
  });
};