// define callbacks
const checkValue = (key: string, value: unknown) => {
if (typeof value !== 'number' || Number.isNaN(value)) throw new Error('error ' + key)
return value
}
const checkRange = (key: string, value: unknown, min: number, max: number = Infinity) => {
if (typeof value !== 'number' || Number.isNaN(value)) throw new Error('error ' + key)
if (value < min || value > max) throw new Error('error')
return value
}
const checkSomething = (key: string, value: unknown, something: number) => {
if (typeof value !== 'number' || Number.isNaN(value)) throw new Error('error ' + key)
if (value === something) throw new Error('error')
return value
}
type Object = { [P: string]: unknown }
const testObject: Record<string, unknown> = { one: 1, two: 'two' }
// main
const evaluate = <
O extends Object,
F extends (key: string, val: unknown) => ReturnType<F>
>(obj: O, prop: keyof O, vfunc: F) => {
if (typeof prop !== 'string') throw new Error('error')
return vfunc(prop, obj[prop])
}
const evaluateTwo = <
O extends Object,
F extends (key: string, val: unknown, ...args: unknown[]) => ReturnType<F>
>(obj: O, prop: keyof O, vfunc: F , ...args: unknown[]) => {
if (typeof prop !== 'string') throw new Error('error')
return vfunc(prop, obj[prop], ...args)
}
evaluate(testObject, 'one', checkValue) // good
evaluate(testObject, 'one', checkRange) // error as expected
// the following expression statements should not fail
evaluateTwo(testObject, 'one', checkRange) // should say missing `min` arg
evaluateTwo(testObject, 'one', checkRange, 1)
evaluateTwo(testObject, 'one', checkRange, 1, 10)
evaluateTwo(testObject, 'one', checkSomething, 1) // should say wrong type number instead of string
In the snippet above, I have defined callback functions checkValue, checkRange, and checkSomething, and showcased the usage of evaluate and evaluateTwo functions for different scenarios. The code also includes error messages and playground links for further reference.