Gymnasium/tests/vector/test_vector_env_info.py

"""Test the vector environment information."""

from __future__ import annotations

from typing import Any, SupportsFloat

import numpy as np
import pytest

import gymnasium as gym
from gymnasium.core import ActType, ObsType
from gymnasium.spaces import Box, Discrete
from gymnasium.utils.env_checker import data_equivalence
from gymnasium.vector import AsyncVectorEnv, SyncVectorEnv, VectorEnv


def test_vector_add_info():
    env = VectorEnv()

    # Test num-envs==1 then expand_dims(sub-env-info) == vector-infos
    env.num_envs = 1
    sub_env_info = {"a": 0, "b": 0.0, "c": None, "d": np.zeros((2,)), "e": Discrete(1)}
    vector_infos = env._add_info({}, sub_env_info, 0)
    expected_vector_infos = {
        "a": np.array([0]),
        "b": np.array([0.0]),
        "c": np.array([None], dtype=object),
        "d": np.zeros(
            (
                1,
                2,
            )
        ),
        "e": np.array([Discrete(1)], dtype=object),
        "_a": np.array([True]),
        "_b": np.array([True]),
        "_c": np.array([True]),
        "_d": np.array([True]),
        "_e": np.array([True]),
    }
    assert data_equivalence(vector_infos, expected_vector_infos)

    # Thought: num-envs>1 then vector-infos should have the same structure as sub-env-info
    env.num_envs = 3
    sub_env_infos = [
        {"a": 0, "b": 0.0, "c": None, "d": np.zeros((2,)), "e": Discrete(1)},
        {"a": 1, "b": 1.0, "c": None, "d": np.zeros((2,)), "e": Discrete(2)},
        {"a": 2, "b": 2.0, "c": None, "d": np.zeros((2,)), "e": Discrete(3)},
    ]

    vector_infos = {}
    for i, info in enumerate(sub_env_infos):
        vector_infos = env._add_info(vector_infos, info, i)

    expected_vector_infos = {
        "a": np.array([0, 1, 2]),
        "b": np.array([0.0, 1.0, 2.0]),
        "c": np.array([None, None, None], dtype=object),
        "d": np.zeros((3, 2)),
        "e": np.array([Discrete(1), Discrete(2), Discrete(3)], dtype=object),
        "_a": np.array([True, True, True]),
        "_b": np.array([True, True, True]),
        "_c": np.array([True, True, True]),
        "_d": np.array([True, True, True]),
        "_e": np.array([True, True, True]),
    }
    assert data_equivalence(vector_infos, expected_vector_infos)

    # Test different structures of sub-infos
    env.num_envs = 3
    sub_env_infos = [
        {"a": 1, "b": 1.0},
        {"c": None, "d": np.zeros((2,))},
        {"e": Discrete(3)},
    ]

    vector_infos = {}
    for i, info in enumerate(sub_env_infos):
        vector_infos = env._add_info(vector_infos, info, i)

    expected_vector_infos = {
        "a": np.array([1, 0, 0]),
        "b": np.array([1.0, 0.0, 0.0]),
        "c": np.array([None, None, None], dtype=object),
        "d": np.zeros((3, 2)),
        "e": np.array([None, None, Discrete(3)], dtype=object),
        "_a": np.array([True, False, False]),
        "_b": np.array([True, False, False]),
        "_c": np.array([False, True, False]),
        "_d": np.array([False, True, False]),
        "_e": np.array([False, False, True]),
    }
    assert data_equivalence(vector_infos, expected_vector_infos)

    # Test recursive structure
    env.num_envs = 3
    sub_env_infos = [
        {"episode": {"a": 1, "b": 1.0}},
        {"episode": {"a": 2, "b": 2.0}, "a": 1},
        {"a": 2},
    ]

    vector_infos = {}
    for i, info in enumerate(sub_env_infos):
        vector_infos = env._add_info(vector_infos, info, i)

    expected_vector_infos = {
        "episode": {
            "a": np.array([1, 2, 0]),
            "b": np.array([1.0, 2.0, 0.0]),
            "_a": np.array([True, True, False]),
            "_b": np.array([True, True, False]),
        },
        "_episode": np.array([True, True, False]),
        "a": np.array([0, 1, 2]),
        "_a": np.array([False, True, True]),
    }
    assert data_equivalence(vector_infos, expected_vector_infos)


class ReturnInfoEnv(gym.Env):
    def __init__(self, infos):
        self.observation_space = Box(0, 1)
        self.action_space = Box(0, 1)

        self.infos = infos

    def reset(
        self,
        *,
        seed: int | None = None,
        options: dict[str, Any] | None = None,
    ) -> tuple[ObsType, dict[str, Any]]:
        return self.observation_space.sample(), self.infos[0]

    def step(
        self, action: ActType
    ) -> tuple[ObsType, SupportsFloat, bool, bool, dict[str, Any]]:
        return self.observation_space.sample(), 0, True, False, self.infos[1]


@pytest.mark.parametrize("vectorizer", [AsyncVectorEnv, SyncVectorEnv])
def test_vectorizers(vectorizer):
    vec_env = vectorizer(
        [
            lambda: ReturnInfoEnv([{"a": 1}, {"c": np.array([1, 2])}]),
            lambda: ReturnInfoEnv([{"a": 2, "b": 3}, {"c": np.array([3, 4])}]),
        ]
    )

    reset_expected_infos = {
        "a": np.array([1, 2]),
        "b": np.array([0, 3]),
        "_a": np.array([True, True]),
        "_b": np.array([False, True]),
    }
    step_expected_infos = {
        "c": np.array([[1, 2], [3, 4]]),
        "_c": np.array([True, True]),
    }

    _, reset_info = vec_env.reset()
    assert data_equivalence(reset_info, reset_expected_infos)
    _, _, _, _, step_info = vec_env.step(vec_env.action_space.sample())
    assert data_equivalence(step_info, step_expected_infos)