CFP - Docs - defaultFalseyValTo

defaultFalseyValTo

(defaultVal: any) => (val: any) => any

Return a default value if a falsey one is passed.

Try It

const defaultToNoName = defaultFalseyValTo('<no name>')

defaultToNoName('mary') // is mary
defaultToNoName('') // is <no name>
defaultToNoName(undefined) // is <no name>
const defaultToNoName = defaultFalseyValTo('<no name>')

defaultToNoName('mary') // is mary
defaultToNoName('') // is <no name>
defaultToNoName(undefined) // is <no name>

Try It

const defaultToNoName =
  defaultFalseyValTo('<no name>')

defaultToNoName('mary') // is mary
defaultToNoName('') // is <no name>
defaultToNoName(undefined) // is <no name>
const defaultToNoName =
  defaultFalseyValTo('<no name>')

defaultToNoName('mary') // is mary
defaultToNoName('') // is <no name>
defaultToNoName(undefined) // is <no name>

Sometimes we want a default value in place of a falsey one. Below, we let people build their own bear. If they don't provide a name, let's name it Teddy.

Try It

const defaultToTeddy = defaultFalseyValTo('Teddy')
const defaultNameToTeddy = update({ name: defaultToTeddy })

const bearsToBuild = [
  {
    name: '',
    shirt: 'blue',
  },
  {
    name: 'Winnie',
    shirt: 'red',
  },
  {
    name: undefined,
    shirt: 'purple',
  },
]

const defaultAllNames = mapValues(defaultNameToTeddy)
const updatedBears = defaultAllNames(bearsToBuild)

console.log(updatedBears)
// [
//   {
//     name: Teddy
//     shirt: blue
//   }, {
//     name: Winnie
//     shirt: red
//   }, {
//     name: Teddy
//     shirt: purple
//   }
// ]
type Bear = {
  name?: string
  shirt: string
}

const defaultToTeddy = defaultFalseyValTo('Teddy')
const defaultNameToTeddy = update({ name: defaultToTeddy })<Bear>

const bearsToBuild: Bear[] = [
  {
    name: '',
    shirt: 'blue',
  },
  {
    name: 'Winnie',
    shirt: 'red',
  },
  {
    name: undefined,
    shirt: 'purple',
  },
]

const defaultAllNames = mapValues(defaultNameToTeddy)<Bear[]>
const updatedBears = defaultAllNames(bearsToBuild)

console.log(updatedBears)
// [
//   { name: Teddy, shirt: blue },
//   { name: Winnie, shirt: red },
//   { name: Teddy, shirt: purple },
// ]

Try It

const defaultToTeddy = defaultFalseyValTo('Teddy')
const defaultNameToTeddy = update({
  name: defaultToTeddy,
})

const bearsToBuild = [
  {
    name: '',
    shirt: 'blue',
  },
  {
    name: 'Winnie',
    shirt: 'red',
  },
  {
    name: undefined,
    shirt: 'purple',
  },
]

const defaultAllNames = mapValues(
  defaultNameToTeddy
)
const updatedBears = defaultAllNames(bearsToBuild)

console.log(updatedBears)
// [
//   {
//     name: Teddy
//     shirt: blue
//   }, {
//     name: Winnie
//     shirt: red
//   }, {
//     name: Teddy
//     shirt: purple
//   }
// ]
type Bear = {
  name?: string
  shirt: string
}

const defaultToTeddy = defaultFalseyValTo('Teddy')
const defaultNameToTeddy = update({
  name: defaultToTeddy,
})<Bear>

const bearsToBuild: Bear[] = [
  {
    name: '',
    shirt: 'blue',
  },
  {
    name: 'Winnie',
    shirt: 'red',
  },
  {
    name: undefined,
    shirt: 'purple',
  },
]

const defaultAllNames = mapValues(
  defaultNameToTeddy
)<Bear[]>
const updatedBears = defaultAllNames(bearsToBuild)

console.log(updatedBears)
// [
//   { name: Teddy, shirt: blue },
//   { name: Winnie, shirt: red },
//   { name: Teddy, shirt: purple },
// ]