generic + overload

onsuccess.helper.ts

interface OnSuccessResponse<T> {
    statusCode: number
    message: string
    data: T
    error: null
}
  
export function onSuccess<T>(): OnSuccessResponse<T>
export function onSuccess<T>(params: { message?: string, data?: T | null }): OnSuccessResponse<T>
export function onSuccess<T>(params: {message?: string, data?: T | null}={}) {
    return {
        statusCode: 200,
        message: params.message || 'ok',
        data: params.data || null,
        error: null
    }
}

const t = onSuccess({data: 1})