add Dataset Class and Tests

tests/test_Dataset.py

@@ -0,0 +1,50 @@
+import unittest
+
+from server.Dataset import Dataset
+
+class DummySnake:
+  def get_history(self):
+    return [
+      {"turn": 1, "data": [{"score": 1}]},
+      {"turn": 2, "data": [{"score": 2}]},
+    ]
+
+class DummyGameBoard:
+  def __init__(self, winners):
+    self.id = "game-1"
+    self.map = "standard"
+    self.winner_snake_names = winners
+    self.snake_class = DummySnake()
+    self.turns = [
+      {"turn": 1, "move": "up", "game_board": {"width": 11, "height": 11}},
+      {"turn": 2, "move": "left", "game_board": {"width": 11, "height": 11}},
+    ]
+
+  def get_type_of_game(self):
+    return {"name": "standard", "is_ladder": False}
+
+class TestDataset(unittest.TestCase):
+  def test_build_only_good_moves_for_wins(self):
+    dataset = Dataset(DummyGameBoard(["me"]))
+    payload = dataset.build(only_good_moves=True)
+
+    self.assertTrue(payload["did_win"])
+    self.assertEqual(payload["total_samples"], 2)
+    self.assertTrue(all(sample["is_good_move"] for sample in payload["samples"]))
+
+  def test_build_returns_no_samples_for_losses_when_only_good(self):
+    dataset = Dataset(DummyGameBoard(["enemy"]))
+    payload = dataset.build(only_good_moves=True)
+
+    self.assertFalse(payload["did_win"])
+    self.assertEqual(payload["total_samples"], 0)
+
+  def test_labels_by_turn(self):
+    winner_labels = Dataset(DummyGameBoard(["me"])).labels_by_turn()
+    loser_labels = Dataset(DummyGameBoard(["enemy"])).labels_by_turn()
+
+    self.assertEqual(winner_labels, {1: True, 2: True})
+    self.assertEqual(loser_labels, {1: False, 2: False})
+
+if __name__ == "__main__":
+  unittest.main()

tests/test_DatasetExporter.py

@@ -0,0 +1,47 @@
+import json
+import tempfile
+import unittest
+from pathlib import Path
+
+from server.DatasetExporter import DatasetExporter
+
+class TestDatasetExporter(unittest.TestCase):
+  def test_export_jsonl(self):
+    with tempfile.TemporaryDirectory() as tmp:
+      input_dir = Path(tmp) / "data"
+      output_file = Path(tmp) / "out" / "dataset.jsonl"
+      game_file = input_dir / "game-1.json"
+      game_file.parent.mkdir(parents=True, exist_ok=True)
+
+      game_payload = {
+        "dataset": {
+          "game": {"id": "g-1", "map": "standard", "type": {"name": "duel"}},
+          "snake": {"type": "BestBattleSnake"},
+          "samples": [
+            {
+              "turn": 1,
+              "move": "up",
+              "is_good_move": True,
+              "game_board": {"width": 11, "height": 11},
+              "history": {"data": []},
+            }
+          ],
+        }
+      }
+      game_file.write_text(json.dumps(game_payload), encoding="utf-8")
+
+      report = DatasetExporter(str(input_dir), str(output_file)).export_jsonl()
+
+      self.assertEqual(report["games_scanned"], 1)
+      self.assertEqual(report["samples_exported"], 1)
+      self.assertTrue(output_file.exists())
+
+      lines = output_file.read_text(encoding="utf-8").strip().splitlines()
+      self.assertEqual(len(lines), 1)
+      first = json.loads(lines[0])
+      self.assertEqual(first["game_id"], "g-1")
+      self.assertEqual(first["move"], "up")
+      self.assertTrue(first["is_good_move"])
+
+if __name__ == "__main__":
+  unittest.main()