test "implicit_fstring_interpolation" {
    let result = 123;
    let s = "{result}";
    // Should be "123"
    assert(strcmp(s, "123") == 0, "Implicit f-string failed");
}

test "implicit_fstring_complex" {
    let a = 10;
    let b = 20;
    let s = "Sum: {a + b}";
    assert(strcmp(s, "Sum: 30") == 0, "Complex implicit f-string failed");
}

test "no_interpolation" {
    let s = "Hello World";
    assert(strcmp(s, "Hello World") == 0, "Plain string failed");
}