foxhunt/crates/ml/tests/ppo_checkpoint_roundtrip_test.rs

#![allow(
    clippy::assertions_on_constants,
    clippy::assertions_on_result_states,
    clippy::clone_on_copy,
    clippy::decimal_literal_representation,
    clippy::doc_markdown,
    clippy::empty_line_after_doc_comments,
    clippy::field_reassign_with_default,
    clippy::get_unwrap,
    clippy::identity_op,
    clippy::inconsistent_digit_grouping,
    clippy::indexing_slicing,
    clippy::integer_division,
    clippy::len_zero,
    clippy::let_underscore_must_use,
    clippy::manual_div_ceil,
    clippy::manual_let_else,
    clippy::manual_range_contains,
    clippy::modulo_arithmetic,
    clippy::needless_range_loop,
    clippy::non_ascii_literal,
    clippy::redundant_clone,
    clippy::shadow_reuse,
    clippy::shadow_same,
    clippy::shadow_unrelated,
    clippy::single_match_else,
    clippy::str_to_string,
    clippy::string_slice,
    clippy::tests_outside_test_module,
    clippy::too_many_lines,
    clippy::unnecessary_wraps,
    clippy::unseparated_literal_suffix,
    clippy::use_debug,
    clippy::useless_vec,
    clippy::wildcard_enum_match_arm,
    clippy::else_if_without_else,
    clippy::expect_used,
    clippy::missing_const_for_fn,
    clippy::similar_names,
    clippy::type_complexity,
    clippy::collapsible_else_if,
    clippy::doc_lazy_continuation,
    clippy::items_after_test_module,
    clippy::map_clone,
    clippy::multiple_unsafe_ops_per_block,
    clippy::unwrap_or_default,
    clippy::assign_op_pattern,
    clippy::needless_borrow,
    clippy::println_empty_string,
    clippy::unnecessary_cast,
    clippy::used_underscore_binding,
    clippy::create_dir,
    clippy::implicit_saturating_sub,
    clippy::exit,
    clippy::expect_fun_call,
    clippy::too_many_arguments,
    clippy::unnecessary_map_or,
    clippy::unwrap_used,
    dead_code,
    unused_imports,
    unused_variables,
    clippy::cloned_ref_to_slice_refs,
    clippy::neg_multiply,
    clippy::while_let_loop,
    clippy::bool_assert_comparison,
    clippy::excessive_precision,
    clippy::trivially_copy_pass_by_ref,
    clippy::op_ref,
    clippy::redundant_closure,
    clippy::unnecessary_lazy_evaluations,
    clippy::if_then_some_else_none,
    clippy::unnecessary_to_owned,
    clippy::single_component_path_imports,
)]
//! PPO Checkpoint Round-Trip Validation Test
//!
//! Proves that saving a PPO model checkpoint and loading it back
//! produces identical action probabilities for the same input state.
//!
//! Run manually:
//! ```sh
//! SQLX_OFFLINE=true cargo test -p ml --test ppo_checkpoint_roundtrip_test -- --ignored --nocapture
//! ```

#![allow(unused_crate_dependencies)]

use anyhow::Result;
use ml::ppo::ppo::{PPOConfig, PPO};
use std::path::PathBuf;
use tracing::info;

#[tokio::test]
#[ignore]
async fn test_ppo_checkpoint_roundtrip() -> Result<()> {
    let checkpoint_dir = tempfile::tempdir()?;
    let state_dim = 54;
    let num_actions = 45;

    // Create PPO model with known config
    let config = PPOConfig {
        state_dim,
        num_actions,
        policy_hidden_dims: vec![128, 64],
        value_hidden_dims: vec![128, 64],
        use_lstm: false,
        ..PPOConfig::default()
    };

    let ppo = PPO::new(config.clone())?;

    // Create test state
    let test_state: Vec<f32> = (0..state_dim).map(|i| (i as f32 * 0.1).sin()).collect();

    // Get greedy action before save (GPU-side argmax, no bulk transfer)
    let action_before = ppo.greedy_action(&test_state)?;

    // Save checkpoint (API takes &PathBuf)
    let checkpoint_path = checkpoint_dir.path().join("checkpoint");

    ppo.save_checkpoint(&checkpoint_path)?;

    // Verify config file exists and is non-empty
    let config_path = checkpoint_path.with_extension("json");
    assert!(config_path.exists(), "Config file not saved");
    assert!(std::fs::metadata(&config_path)?.len() > 0);

    // Load into a fresh model (API takes &PathBuf)
    let loaded_ppo = PPO::load_checkpoint(&checkpoint_path)?;

    // Get greedy action after load — must match exactly
    let action_after = loaded_ppo.greedy_action(&test_state)?;

    assert_eq!(
        action_before, action_after,
        "Greedy action mismatch after checkpoint roundtrip: {:?} vs {:?}",
        action_before, action_after,
    );

    let config_bytes = std::fs::metadata(&config_path)?.len();
    info!("Checkpoint round-trip validation passed");
    info!(config_bytes, "Config checkpoint size");

    Ok(())
}