Error in type in overloaded function

[whpac]

TypeScript Version: 3.9.6 (tested also with 4.0.0-beta and Nightly in TS Playground and still present)

Search Terms: overload

Code

function foo(x: number): object;
function foo(x: number[]): object[];
function foo(x: number | number[]): object | object[]{
    // Do something
    return typeof x == 'number' ? {} : [{}];
}

function bar(x: number): object;
function bar(x: number[]): object[];
function bar(x: number | number[]): object | object[]{
    return foo(x); // Error...
}

Expected behavior: Compiles without an error

Actual behavior: Compiler throws an error: No overload matches this call (1) number | number[] is not assignable to number, (2) number | number[] is not assignable to number[]

Playground Link: Here

Related Issues: I haven't found any

Edit: I've tweaked the code in order to fit the type declaration. This change has no impact on the actual bug I'm reporting.

[MartinJohns]

Duplicate of #39885. Search terms used: overload union

[typescript-bot]

This issue has been marked as a 'Duplicate' and has seen no recent activity. It has been automatically closed for house-keeping purposes.