Remove all falsy values from an object and its nested children

This function will remove all falsy values like null, undefined, 0, '', false from an object and its nested children.

Allow passing custom falsyValues to remove and return a new object without the falsy values.

if you prefer typescript:

export function removeFalsy<T = any>(obj: {}, falsyValues: any[] = ['', null, undefined]): T {
  if (!obj || typeof obj !== 'object') {
    return obj as any
  }
  return Object.entries(obj).reduce((a, c) => {
    let [k, v]: [string, any] = c
    if (falsyValues.indexOf(v) === -1 && JSON.stringify(removeFalsy(v, falsyValues)) !== '{}') {
      a[k] = typeof v === 'object' && !Array.isArray(v) ? removeFalsy(v, falsyValues) : v
    }
    return a
  }, {} as any) as T
}

and a version for plain javascript if you don't like too much as and any:

function removeFalsy(obj, falsyValues = ['', null, undefined]) {
  if (!obj || typeof obj !== 'object') {
    return obj
  }
  return Object.entries(obj).reduce((a, c) => {
    let [k, v] = c
    if (falsyValues.indexOf(v) === -1 && JSON.stringify(removeFalsy(v, falsyValues)) !== '{}') {
      a[k] = typeof v === 'object' && !Array.isArray(v) ? removeFalsy(v, falsyValues) : v
    }
    return a
  }, {})
}

Example usage

let obj = {
  a: 1,
  b: 0,
  c: '',
  d: null,
  e: undefined,
  f: false,
  g: {
    a: 1,
    b: 0,
    c: '',
    d: null,
    e: undefined,
    f: false,
  },
  j: {},
  h: [],
  i: [1],
}
console.log(removeFalsy(obj, [0, false, '', null, undefined]))
// 👉 { a: 1, g: { a: 1 }, i: [ 1 ] }

Happy coding!