indexedAccessConstraints.ts(2,9): error TS2322: Type 'T[keyof T]' is not assignable to type 'number'.
  Type 'T[string] | T[number] | T[symbol]' is not assignable to type 'number'.
    Type 'T[string]' is not assignable to type 'number'.


==== indexedAccessConstraints.ts (1 errors) ====
    function foo<T extends object>(a: T[keyof T]) {
        let b: number = a;  // Error
            ~
!!! error TS2322: Type 'T[keyof T]' is not assignable to type 'number'.
!!! error TS2322:   Type 'T[string] | T[number] | T[symbol]' is not assignable to type 'number'.
!!! error TS2322:     Type 'T[string]' is not assignable to type 'number'.
    }
    
    // Repro from #54522
    
    export function methodFnLength<T extends {}, K extends keyof T>(obj: T, methodKey: K): number {
        const fn = obj[methodKey];
        if (typeof fn !== 'function') {
            return 0;
        }
        return fn.length;
    }
    
    // Repro from #54837
    
    function getField<T extends object>(x: T | null, k: keyof T) {
        const result = x ? x[k] : null;
        return result;  // T[keyof T] | null
    }