Usage

Use in your babel plugin as follows. It works the same as @babel/helpers addHelper,
so you can use it anywhere in your visitor.

I made it like @babel/helpers, so it can be used in the same way except loading helpers.

@babel-helpers#usage(inside a plugin)

Only three things to do.

• 1. Define UDF helpers
• 2. Loading helpers in pre()
• 3. Use addUDFHelpers like addHelpers of @babel/helpers

Try

1. Define Helpers

See Define UDF Helpers

2. Loading helpers in pre()

import { useDangerousUDFHelpers } from 'babel-udf-helpers';
/** 1. Define UDF helpers */
import helpers from './helpers';

export default function({types: t}){
  pre(){
    /** 2. Loading helpers in pre() */
    useDangerousUDFHelpers(this, { helpers });
  },
  visitor: {
    /** something */
  }
}

3. Use addUDFHelpers like addHelpers of @babel/helpers

import { useDangerousUDFHelpers } from 'babel-udf-helpers';
/* 1. Define UDF helpers */
import helpers from './helpers';

export default function({types: t}){
  pre(){
    /* 2. Loading helpers in pre() */
    useDangerousUDFHelpers(this, { helpers });
  },
  visitor: {
    Program(path){
      /* 3. Use addUDFHelpers like addHelpers of @babel/helpers */
      const identifier = this.addUDFHelper("programHelper")
    },
    ImportDeclaration(path) {
      /* 3. Use addUDFHelpers like addHelpers of @babel/helpers */
      const identifier = this.addUDFHelper("importHelper")
    }
  }
}

Tips

Once the helper is loaded, it will be retained until the execution of your babel-plugin.
If you want to delete the helper loaded in the middle of traverse, please execute clearAllUDFHelpers.

import { clearAllUDFHelpers } from 'babel-udf-helpers'

clearAllUDFHelpers();

this.addUDFHelper("programHelper") /* # => ReferenceError Unknown helper programHelper */
this.addHelper("typeof") /* Not Error */

WARNING

• Helpers defined in @babel/helpers do not disappear.