import os

const vexe = @VEXE
const tests_dir = os.dir(@FILE)
const v3_dir = os.dir(tests_dir)
const v3_src = os.join_path(v3_dir, 'v3.v')

// Slicing a fixed array must evaluate the slice bounds exactly once, so
// side-effecting bound expressions are not run multiple times in the generated C.
fn test_fixed_array_slice_evaluates_bounds_once() {
    v3_bin := os.join_path(os.temp_dir(), 'v3_fixed_slice_test')
    build := os.execute('${vexe} -o ${v3_bin} ${v3_src}')
    assert build.exit_code == 0, build.output

    src := '
fn start_idx() int {
    println("eval")
    return 1
}

fn main() {
    mut a := [3]int{}
    s := a[start_idx()..3]
    println(s.len)
}
'
    src_file := os.join_path(os.temp_dir(), 'v3_fixed_slice.v')
    os.write_file(src_file, src) or { panic(err) }
    bin := os.join_path(os.temp_dir(), 'v3_fixed_slice_bin')
    os.rm(bin) or {}
    compile := os.execute('${v3_bin} ${src_file} -b c -o ${bin}')
    assert compile.exit_code == 0, compile.output
    run := os.execute(bin)
    assert run.exit_code == 0, run.output
    assert run.output.count('eval') == 1, run.output
}