Run library, checks and downloads in background threads with parallel fetching

tests/test_prune.py

@@ -0,0 +1,51 @@
+"""Tests for prune version-selection logic (MetadataStore._select_versions_to_keep)."""
+
+from src.config import MetadataStore
+from src.models import DownloadedInstaller, GameRecord, InstallerType, PruneStrategy
+
+
+def _record(version_years: dict[str, int]) -> GameRecord:
+    """Build a GameRecord with one installer per (version, year)."""
+    installers = [
+        DownloadedInstaller(
+            filename=f"setup_{v}.exe",
+            size=1,
+            version=v,
+            language="en",
+            installer_type=InstallerType.GAME,
+            downloaded_at=f"{year}-01-01T00:00:00",
+        )
+        for v, year in version_years.items()
+    ]
+    return GameRecord(game_id="1", name="Game", installers=installers)
+
+
+VERSION_YEARS = {"1": 2020, "2": 2020, "3": 2021, "4": 2022, "5": 2022}
+ALL = ["1", "2", "3", "4", "5"]
+
+
+def _keep(strategy: PruneStrategy, keep_latest: int = 1) -> set[str]:
+    record = _record(VERSION_YEARS)
+    return MetadataStore._select_versions_to_keep(record, ALL, keep_latest, strategy)
+
+
+def test_returns_all_when_fewer_than_keep() -> None:
+    record = _record({"1": 2020})
+    assert MetadataStore._select_versions_to_keep(record, ["1"], 1, PruneStrategy.LATEST_N) == {"1"}
+
+
+def test_latest_n_keeps_only_recent() -> None:
+    assert _keep(PruneStrategy.LATEST_N, keep_latest=1) == {"5"}
+    assert _keep(PruneStrategy.LATEST_N, keep_latest=2) == {"4", "5"}
+
+
+def test_latest_n_oldest_adds_first() -> None:
+    assert _keep(PruneStrategy.LATEST_N_OLDEST, keep_latest=1) == {"1", "5"}
+
+
+def test_yearly_keeps_one_per_year_plus_latest() -> None:
+    assert _keep(PruneStrategy.YEARLY, keep_latest=1) == {"2", "3", "5"}
+
+
+def test_latest_n_yearly_oldest_combines_all() -> None:
+    assert _keep(PruneStrategy.LATEST_N_YEARLY_OLDEST, keep_latest=1) == {"1", "2", "3", "5"}