feat: initial release

tests/test_model_instance_cache.py

@@ -0,0 +1,123 @@
+# SimpleSyrup - workflow-focused ComfyUI extensions for image generation
+# Copyright (C) 2026  Artificial Sweetener and contributors
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+"""Tests for process-level model instance cache mechanics."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+import pytest
+
+from simple_syrup.runtime.model_instance_cache import ModelInstanceCache
+
+
+@dataclass(frozen=True)
+class FakeCacheKey:
+    """Identify fake loaded objects in cache tests."""
+
+    value: str
+
+
+class LoadFailure(RuntimeError):
+    """Distinct exception raised by fake loaders."""
+
+
+def test_get_or_load_calls_loader_on_first_miss() -> None:
+    """A cache miss stores and returns the loader result."""
+
+    loaded = object()
+    calls = 0
+
+    def load() -> object:
+        """Return a fixed fake loaded model."""
+
+        nonlocal calls
+        calls += 1
+        return loaded
+
+    cache: ModelInstanceCache[FakeCacheKey, object] = ModelInstanceCache()
+
+    assert cache.get_or_load(FakeCacheKey("model"), load) is loaded
+    assert calls == 1
+
+
+def test_get_or_load_reuses_cached_instance() -> None:
+    """A cache hit returns the original object without loading again."""
+
+    first = object()
+    calls = 0
+
+    def load() -> object:
+        """Return a new fake loaded model."""
+
+        nonlocal calls
+        calls += 1
+        return first
+
+    cache: ModelInstanceCache[FakeCacheKey, object] = ModelInstanceCache()
+
+    assert cache.get_or_load(FakeCacheKey("model"), load) is first
+    assert cache.get_or_load(FakeCacheKey("model"), load) is first
+    assert calls == 1
+
+
+def test_get_or_load_separates_different_keys() -> None:
+    """Distinct keys keep distinct loaded instances."""
+
+    calls = 0
+
+    def load() -> object:
+        """Return a unique fake loaded model."""
+
+        nonlocal calls
+        calls += 1
+        return object()
+
+    cache: ModelInstanceCache[FakeCacheKey, object] = ModelInstanceCache()
+
+    first = cache.get_or_load(FakeCacheKey("first"), load)
+    second = cache.get_or_load(FakeCacheKey("second"), load)
+
+    assert second is not first
+    assert calls == 2
+
+
+def test_get_or_load_propagates_load_failures() -> None:
+    """Loader exceptions surface to callers."""
+
+    def load() -> object:
+        """Raise a fake loading failure."""
+
+        raise LoadFailure("failed")
+
+    cache: ModelInstanceCache[FakeCacheKey, object] = ModelInstanceCache()
+
+    with pytest.raises(LoadFailure, match="failed"):
+        cache.get_or_load(FakeCacheKey("model"), load)
+
+
+def test_get_or_load_does_not_cache_failed_loads() -> None:
+    """A failed load leaves the key available for a later successful load."""
+
+    calls = 0
+    loaded = object()
+
+    def load() -> object:
+        """Fail once, then return a fake loaded model."""
+
+        nonlocal calls
+        calls += 1
+        if calls == 1:
+            raise LoadFailure("failed")
+        return loaded
+
+    cache: ModelInstanceCache[FakeCacheKey, object] = ModelInstanceCache()
+    key = FakeCacheKey("model")
+
+    with pytest.raises(LoadFailure, match="failed"):
+        cache.get_or_load(key, load)
+
+    assert cache.get_or_load(key, load) is loaded
+    assert calls == 2