getFunctionParams

getFunctionParams.ts

/**
 * Returns parameters of a function
 * Works for anonymous and named functions
 * @param {Function} func
 */
const getFunctionParams = (func: Function): string[] =>
  new RegExp('(?:\\s*|^)\\s*\\((.*?)\\)')
    .exec(func.toString().replace(/\n/g, ''))![1]
    .replace(/\/\*.*?\*\//g, '')
    .replace(/ /g, '')
    .split(',')

export default getFunctionParams

/*

function myFunction(x: number, z: string) {
  return { x, z, a, b }
}

const fun = (y: string) => {
  return y
}

getFunctionParams(myFunction) // [ 'x', 'z' ]
getFunctionParams(fun) // [ 'y']

*/