//! Minimal, robust smoke test for the VM crate.
//!
//! Intentionally does not assert legacy ISA behavior. It only ensures that:
//! - The VM type can be instantiated without panicking.
//! - Deterministic test utilities work as expected (reproducible RNG).

use prometeu_test_support::{next_u64, rng_from_seed};
use prometeu_vm::VirtualMachine;

#[test]
fn vm_instantiation_is_stable() {
    // Create a VM with empty ROM and empty constant pool.
    let vm = VirtualMachine::new(vec![], vec![]);
    // Basic invariant checks that should remain stable across refactors.
    assert_eq!(vm.pc, 0);
    assert!(!vm.halted);
}

#[test]
fn deterministic_rng_sequences_match() {
    // Demonstrate deterministic behavior without relying on specific values.
    let mut a = rng_from_seed(12345);
    let mut b = rng_from_seed(12345);

    for _ in 0..8 {
        // Same seed => same sequence
        assert_eq!(next_u64(&mut a), next_u64(&mut b));
    }
}