如何在创建babel插件时转换箭头功能

Question

我目前正在研究babeljs以及他们将代码从ESX转换为ES5的方式。

实际上，我正在尝试编写一个真正（非常）简单的插件来翻译一些简单的语句，并且在尝试转换箭头函数和返回语句时我被卡住了。

这是我想要传达的代码：

const x = () => null;

以下是我想要的内容：

var creatingAVariablex = function () {
    return null;
};

从现在开始，我的插件中包含以下代码：

module.exports = function({ types: t }) {
  return {
    visitor: {
      Identifier(path, state) {
        path.node.name = "creatingAVariable" + path.node.name;
      },
      ArrowFunctionExpression(path) {
        /**
         * Here, I should transpile () => to function() {}
         * special case: when path.node.expression, I have to add curly around the body + return statement
         * I tried with the following stuff, but it seems that I'm missing something concerning the way
         * I should create the functionExpression
         */
        path.replaceWith(t.functionExpression(path.node.body));
      },
      VariableDeclaration(path) {
        path.node.kind = "var";
      }
    }
  };
};

我不知道从哪里开始，我无法找到API定义来创建functionExpression。

有人知道我能处理这个案件的人吗？

编辑：我设法使其与

一起使用

module.exports = function({ types: t }) {
  return {
    visitor: {
      Identifier(path, state) {
        path.node.name = "creatingAVariable" + path.node.name;
      },
      ArrowFunctionExpression(path) {
        /**
         * Here, I should transpile () => to function() {}
         * special case: when path.node.expression, I have to add curly around the body + return statement
         * I tried with the following stuff, but it seems that I'm missing something concerning the way
         * I should create the functionExpression
         */
        path.replaceWith(
          t.functionExpression(
            t.Identifier("func"),
            [],
            t.BlockStatement([t.returnStatement(path.node.body)])
          )
        );
      },
      VariableDeclaration(path) {
        path.node.kind = "var";
      }
    }
  };
};