ObjectAssign.md

typelab / utils / ObjectAssign

type ObjectAssign<Target, Source> = _ObjectAssignPreCheck<Target, Source, Target extends Primitive ? _ObjectAssignPrimitive<Target, Source> : Target extends ReadonlyArray ? _ObjectAssignArray<Target, Source> : IsObjectLiteral<Target> extends true ? _ObjectAssignObject<Target, Source> : Target & Source>;

Assign properties of Source into Target.

The result of type follows the actual result of Object.assign.

Type Parameters

Type Parameter	Default type	Description
Target	‐	The type to receive the assignment.
Source	never	The type to be assigned to the Target.

Returns

A new type that combines both Target and Source.

Example

// { a: string; b: string; c: boolean }
type Assign1 = ObjectAssign<{ a: string; b: number }, { b: string; c: boolean }>;

// { a: string; 0: string }
type Assign2 = ObjectAssign<{ a: string }, [string]>;

// { [x: number]: string, a: string }
type Assign3 = ObjectAssign<{ a: string }, string[]>;

// [number, number]
type Assign4 = ObjectAssign<[string], [number, number]>;

// (string | number)[]
type Assign5 = ObjectAssign<string[], [number, number]>;

// (string | number)[]
type Assign6 = ObjectAssign<string[], number[]>;

// [number, string]
type Assign7 = ObjectAssign<[string], { 0: number; 1: string }>;

// (string | number)[]
type Assign8 = ObjectAssign<[number], 'str'>;

// { [x: number]: string, a: string }
type Assign9 = ObjectAssign<{a: string}, 'str'>;