The following works:
function testFn(payload: { data: string }) { }
expect(testFn).type.tobeCallableWith({ data: "test" });
However, the generic overload doesn't work:
function testFn(payload: { data: string }) { }
expect<typeof testFn>().type.tobeCallableWith({ data: "test" });
The latter, when executed throws this error: Error: A type argument for 'Source' must be a callable type.