fn foo1() ?int {
    return if true { 0 } else { none }
}

fn foo2() ?int {
    return if true { 1 } else { error('foo2 error') }
}

fn foo3() ?int {
    return if false { 1 } else { error('foo3 error') }
}

fn foo4() ?int {
    return if true { 2 } else { 0 }
}

fn test_if_expr_of_option() {
    a1 := foo1() or { panic('error') }
    println(a1)
    assert a1 == 0

    a2 := foo2() or { panic('error') }
    println(a2)
    assert a2 == 1

    if _ := foo3() {
        assert false
    } else {
        assert err.msg() == 'foo3 error'
    }

    a4 := foo4() or { panic('error') }
    println(a4)
    assert a4 == 2
}

fn foo_complex() ?int {
    a := 2
    return if a > 1 {
        mut b := 1
        b *= 10
        b
    } else {
        mut c := 0
        c += 2
        println(c)
        none
    }
}

fn test_if_expr_of_option_complex() {
    a := foo_complex() or { panic('error') }
    println(a)
    assert a == 10
}