How to infer type by wrapped function

[mysteryven]

function defineObj<M>(params: ??How to define??) {
    // I only care about get type hinting by using `defineObj(params)`
    // ... omit how to inject `getMethod` to params.__proto__
    return params
}

defineObj({
    update: {
        foo2() {
            this.getMethod("foo", '1') // expect it will tell us the second param is `number`
        }
    },
    methods: {
        foo: (num: number) => num,
        bar() {
            this.getMethod("foo", '1') // expect it will tell us the second param is `number`
        }
    }
})

expect

when call this.getMethod:

this.getMethod("foo", 1) // right
this.getMethod("foo", `1`) // false

Is there some way to complete it ?