feat(training): implement LanderCliEnv wrapping the GameCli subprocess

Training/tests/test_lander_cli_env.py

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+"""Unit tests for LanderCliEnv."""
+from pathlib import Path
+
+import numpy as np
+import pytest
+from gymnasium.utils.env_checker import check_env
+
+# Add parent dir to sys.path so we can import lander_cli_env
+import sys
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+from lander_cli_env import LanderCliEnv
+
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+CLI_BINARY = REPO_ROOT / "publish" / "GameCli" / "GameCli"
+
+
+@pytest.fixture(scope="module")
+def cli_binary_exists():
+    if not CLI_BINARY.exists():
+        pytest.skip(f"CLI binary not found at {CLI_BINARY} — run `dotnet publish GameCli -c Release -o publish/GameCli`")
+    return CLI_BINARY
+
+
+def test_env_opens_and_closes(cli_binary_exists):
+    env = LanderCliEnv(cli_binary=str(cli_binary_exists))
+    env.close()  # should not raise
+
+
+def test_observation_space_is_seven_dim(cli_binary_exists):
+    env = LanderCliEnv(cli_binary=str(cli_binary_exists))
+    try:
+        assert env.observation_space.shape == (7,)
+    finally:
+        env.close()
+
+
+def test_action_space_is_discrete_four(cli_binary_exists):
+    env = LanderCliEnv(cli_binary=str(cli_binary_exists))
+    try:
+        assert env.action_space.n == 4
+    finally:
+        env.close()
+
+
+def test_reset_returns_seven_dim_observation(cli_binary_exists):
+    env = LanderCliEnv(cli_binary=str(cli_binary_exists))
+    try:
+        obs, info = env.reset(seed=42)
+        assert isinstance(obs, np.ndarray)
+        assert obs.shape == (7,)
+        assert obs.dtype == np.float32
+    finally:
+        env.close()
+
+
+def test_step_advances_and_returns_five_tuple(cli_binary_exists):
+    env = LanderCliEnv(cli_binary=str(cli_binary_exists))
+    try:
+        env.reset(seed=0)
+        obs, reward, terminated, truncated, info = env.step(0)  # noop
+        assert obs.shape == (7,)
+        assert isinstance(reward, float)
+        assert terminated is False  # never terminates
+        assert isinstance(truncated, bool)
+    finally:
+        env.close()
+
+
+def test_reset_randomizes_target_across_episodes(cli_binary_exists):
+    env = LanderCliEnv(cli_binary=str(cli_binary_exists))
+    try:
+        # Two resets with different seeds should generally give different targets.
+        env.reset(seed=1)
+        target1 = env._target
+        env.reset(seed=2)
+        target2 = env._target
+        assert target1 != target2
+    finally:
+        env.close()
+
+
+def test_truncation_at_max_steps(cli_binary_exists):
+    env = LanderCliEnv(cli_binary=str(cli_binary_exists), max_episode_steps=5)
+    try:
+        env.reset(seed=0)
+        truncated = False
+        for _ in range(5):
+            _, _, _, truncated, _ = env.step(0)
+        assert truncated is True
+    finally:
+        env.close()
+
+
+def test_check_env_passes(cli_binary_exists):
+    """Gymnasium's own env sanity checker — spaces, dtypes, reset/step contract."""
+    env = LanderCliEnv(cli_binary=str(cli_binary_exists), max_episode_steps=50)
+    try:
+        # skip_render_check because we don't implement rendering
+        check_env(env.unwrapped, skip_render_check=True)
+    finally:
+        env.close()