ts-type-helper

Add \"missing\" types for Typescript !

Examples:

Strongly typed iterator versions of for (let key of Object.entries(obj))
``ts
// key is keyof typeof obj
// not "string" as with Object.entries(obj)
for (let key of iterate.entries(obj))
`

isKeyOf, keyOf and other base functionality to make TS better like an iterator.entries() to replace Object.entires ect.

Why?

For some elements of Typescript type-gymnastics is required to get the correct type.
This library tries to make it easier to get the correct type without having to spend time on type-gymnastics,
and still keep the type-safety correct.

Install

`bash
npm install --save-dev ts-type-helper
`

Usage

import the functions or types you need from the library with
`ts
import { XXX } from 'ts-type-helper';
`

Examples

Iterate over object keys and values:

`ts
import { interator } from 'ts-type-helper';

const obj = { a: 1, b: 2 };

for (const [key, value] of interator.entries(obj)) {
// key is 'a' | 'b'
console.log(key, value);
// with Object.entries(obj) key would be string
}

`

Object key check and casting:

`ts
import { isKeyOf, keyOf, keyOfCast } from 'ts-type-helper';

const obj = { a: 1, b: 2 };

for (const key of Object.keys(obj)) {
// Problem: key is string
console.log(key, obj[key]) // error
// isKeyOf
if (isKeyOf(key, obj)) {
console.log(key, obj[key]) // key is 'a' | 'b'
}
// keyOfCast
var k = keyOfCast(key, obj) // k is 'a' | 'b' | undefined
console.log(obj[k]) // error (k could be undefined)
if (k) {
console.log(obj[k]) // k is 'a' | 'b'
}
// keyOf
console.log(key, obj[keyOf(key, obj)]) // key is 'a' | 'b'
}

``