ts-utility-functions

Utility functions for TypeScript

Installation

``bash
npm install ts-utility-functions
`

Usage

$3

#### str.is
`typescript
str.is('') // true
str.is(123) // false
vals.filter(str.is) // filter out non-string values
`

#### str.isStartWith
`typescript
str.isStartWith('abc')('a') // true
str.isStartWith('abc')('b') // false
vals.filter(str.isStartWith('a')) // filter out values that do not start with 'a'
`




$3

#### assert.type, assert.never
`typescript
import { assert } from 'ts-utility-functions';

// assert.type
type Currency = 'USD' | 'EUR';
const currency: Currency = 'USD';

switch (currency) {
case 'USD':
break;
case 'EUR':
break;
default:
assert.type(currency); // compilation - ok, runtime - ok
assert.never(currency); // compilation - ok, runtime - ok
}

switch (currency) {
case 'USD':
break;
default:
assert.type(currency); // compilation - error, runtime - ok
assert.never(currency); // compilation - error, runtime - ok
}

`




$3

#### obj.copyIntersectingFields
`typescript
const a = { a: 1, b: 2, c: 3 }
const b = { a: 0, b: 0 }
copyIntersectingFields(a, b, ['a', 'b'])
console.log(b) // { a: 1, b: 2 }
`

#### obj.copyIntersectingFields.toNew
`typescript
const a = { a: 1, b: 2, c: 3 }
class B {
constructor(public a: number, public b: number) {}
}
const b = copyIntersectingFields.toNew(a, B, ['a', 'b'])
console.log(b) // A { a: 1, b: 2 }
`

#### obj.merge
`typescript
const a = { a: 1, b: 2 }
const b = { b: 3, c: 4 }
const c = { c: 5, d: 6 }
const d = merge(a, b, c)
console.log(d) // { a: 1, b: 3, c: 5, d: 6 }
`

#### obj.vals
`typescript
const a = { a: 1, b: 2, c: '3' }
const b = vals(a)
console.log(b) // [1, 2, '3'] as (string | number)[]

const a = { a: 1, b: 2, c: '3' } as const
const b = vals(a)
console.log(b) // [1, 2, '3'] as (1 | 2 | '3')[]
`

#### obj.keys
`typescript
const a = { a: 1, b: 2, c: 3 }
const b = keys(a)
console.log(b) // ['a', 'b', 'c'] as ('a', 'b', 'c')[]
`

$3

$3


`typescript
const a = fn.noop() // does nothing (returns undefined)
`

$3

`typescript
const a = await fn.noopAsync() // does nothing (returns Promise)
`

$3

$3

`typescript
arr.is([]) // true
arr.is([1, 2, 3]) // true
vals.filter(arr.is) // filter out non-array values
`

$3

`typescript
arr.isNot([]) // false
arr.isNot([1, 2, 3]) // false
vals.filter(arr.isNot) // filter out array values
`

$3

`typescript
arr.req([]) // []
arr.req([1, 2, 3]) // [1, 2, 3]
arr.req(null) // throws error
`

$3

`typescript
arr.isEmpty([]) // true
arr.isEmpty([1, 2, 3]) // false
vals.filter(arr.isEmpty) // filter out non-empty arrays
`

$3

`typescript
arr.isNotEmpty([]) // false
arr.isNotEmpty([1, 2, 3]) // true
vals.filter(arr.isNotEmpty) // filter out empty arrays
`

$3

`typescript
arr.isEmptySafe([]) // true
arr.isEmptySafe(null) // true
arr.isEmptySafe(undefined) // true
arr.isEmptySafe([1, 2, 3]) // false
vals.filter(arr.isEmptySafe) // filter out non-empty arrays
`

$3

`typescript
arr.isNotEmptySafe([]) // false
arr.isNotEmptySafe(null) // false
arr.isNotEmptySafe(undefined) // false
arr.isNotEmptySafe([1, 2, 3]) // true
vals.filter(arr.isNotEmptySafe) // filter out empty arrays
``