Add tests for cache case resolution (from PR #4822) (#4823)

Tests for resolve_cached_repo_id_case and get_model_config case
resolution, separated from the runtime changes in PR #4822.

studio/backend/tests/test_cache_case_resolution.py

@@ -0,0 +1,120 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+from pathlib import Path
+import sys
+import types
+
+# Keep this test runnable in lightweight environments where optional logging
+# deps are not installed.
+if "structlog" not in sys.modules:
+
+    class _DummyLogger:
+        def __getattr__(self, _name):
+            return lambda *args, **kwargs: None
+
+    sys.modules["structlog"] = types.SimpleNamespace(
+        BoundLogger = _DummyLogger,
+        get_logger = lambda *args, **kwargs: _DummyLogger(),
+    )
+
+from utils.paths.path_utils import (
+    resolve_cached_repo_id_case,
+    get_cache_case_resolution_stats,
+    reset_cache_case_resolution_state,
+)
+import utils.paths.path_utils as path_utils
+
+
+def _mk_cache_repo(cache_root: Path, repo_id: str) -> Path:
+    repo_dir = cache_root / f"models--{repo_id.replace('/', '--')}"
+    repo_dir.mkdir(parents = True, exist_ok = True)
+    return repo_dir
+
+
+def test_resolve_cached_repo_id_case_exact_hit(tmp_path, monkeypatch):
+    reset_cache_case_resolution_state()
+    _mk_cache_repo(tmp_path, "Org/Model")
+    monkeypatch.setattr(path_utils, "_hf_hub_cache_dir", lambda: tmp_path)
+
+    resolved = resolve_cached_repo_id_case("Org/Model")
+
+    assert resolved == "Org/Model"
+    stats = get_cache_case_resolution_stats()
+    assert stats["calls"] == 1
+    assert stats["exact_hits"] == 1
+    assert stats["variant_hits"] == 0
+
+
+def test_resolve_cached_repo_id_case_variant_hit(tmp_path, monkeypatch):
+    reset_cache_case_resolution_state()
+    _mk_cache_repo(tmp_path, "Org/Model")
+    monkeypatch.setattr(path_utils, "_hf_hub_cache_dir", lambda: tmp_path)
+
+    resolved = resolve_cached_repo_id_case("org/model")
+
+    assert resolved == "Org/Model"
+    stats = get_cache_case_resolution_stats()
+    assert stats["variant_hits"] == 1
+    assert stats["tie_breaks"] == 0
+
+
+def test_resolve_cached_repo_id_case_tie_break_deterministic(tmp_path, monkeypatch):
+    reset_cache_case_resolution_state()
+    _mk_cache_repo(tmp_path, "Org/Model")
+    _mk_cache_repo(tmp_path, "org/model")
+    monkeypatch.setattr(path_utils, "_hf_hub_cache_dir", lambda: tmp_path)
+
+    resolved = resolve_cached_repo_id_case("oRg/mOdEl")
+
+    # Deterministic rule: lexical sort of candidate repo ids.
+    assert resolved == "Org/Model"
+    stats = get_cache_case_resolution_stats()
+    assert stats["variant_hits"] == 1
+    assert stats["tie_breaks"] == 1
+
+
+def test_resolve_cached_repo_id_case_no_cache_fallback(tmp_path, monkeypatch):
+    reset_cache_case_resolution_state()
+    monkeypatch.setattr(path_utils, "_hf_hub_cache_dir", lambda: tmp_path)
+
+    resolved = resolve_cached_repo_id_case("Org/Missing")
+
+    assert resolved == "Org/Missing"
+    stats = get_cache_case_resolution_stats()
+    assert stats["fallbacks"] == 1
+    assert stats["variant_hits"] == 0
+    assert stats["exact_hits"] == 0
+
+
+def test_resolve_cached_repo_id_case_memoization(tmp_path, monkeypatch):
+    reset_cache_case_resolution_state()
+    _mk_cache_repo(tmp_path, "Org/Model")
+    monkeypatch.setattr(path_utils, "_hf_hub_cache_dir", lambda: tmp_path)
+
+    first = resolve_cached_repo_id_case("org/model")
+    second = resolve_cached_repo_id_case("org/model")
+
+    assert first == "Org/Model"
+    assert second == "Org/Model"
+    stats = get_cache_case_resolution_stats()
+    assert stats["calls"] == 2
+    assert stats["variant_hits"] == 1
+    assert stats["memo_hits"] == 1
+
+
+def test_resolve_cached_repo_id_case_late_cache_population(tmp_path, monkeypatch):
+    """Regression guard: memoized fallback should not hide a later cache variant."""
+    reset_cache_case_resolution_state()
+    monkeypatch.setattr(path_utils, "_hf_hub_cache_dir", lambda: tmp_path)
+
+    first = resolve_cached_repo_id_case("org/model")
+    assert first == "org/model"
+
+    # Simulate cache being populated after first miss (e.g. another code path/download).
+    _mk_cache_repo(tmp_path, "Org/Model")
+
+    second = resolve_cached_repo_id_case("org/model")
+
+    # Desired behavior: second lookup should pick up the now-existing variant.
+    assert second == "Org/Model"

studio/backend/tests/test_models_get_model_config_case_resolution.py

@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
+
+import asyncio
+import sys
+import types
+
+# Keep this test runnable in lightweight environments where optional logging
+# deps are not installed.
+if "structlog" not in sys.modules:
+
+    class _DummyLogger:
+        def __getattr__(self, _name):
+            return lambda *args, **kwargs: None
+
+    sys.modules["structlog"] = types.SimpleNamespace(
+        BoundLogger = _DummyLogger,
+        get_logger = lambda *args, **kwargs: _DummyLogger(),
+    )
+
+import routes.models as models_route
+import utils.models.model_config as model_config_module
+
+
+def test_get_model_config_resolves_cached_case_before_model_checks(monkeypatch):
+    calls: dict[str, str] = {}
+
+    class _DummyModelConfig:
+        is_lora = False
+        base_model = None
+
+    def _record_load(model_name):
+        calls["load_model_defaults"] = model_name
+        return {}
+
+    def _record_vision(model_name, hf_token = None):
+        calls["is_vision_model"] = model_name
+        return False
+
+    def _record_embedding(model_name, hf_token = None):
+        calls["is_embedding_model"] = model_name
+        return False
+
+    def _record_audio(model_name, hf_token = None):
+        calls["detect_audio_type"] = model_name
+        return None
+
+    def _record_from_identifier(cls, model_name):
+        calls["from_identifier"] = model_name
+        return _DummyModelConfig()
+
+    monkeypatch.setattr(models_route, "is_local_path", lambda _: False)
+    monkeypatch.setattr(
+        models_route, "resolve_cached_repo_id_case", lambda _: "Org/Model"
+    )
+    monkeypatch.setattr(models_route, "load_model_defaults", _record_load)
+    monkeypatch.setattr(models_route, "is_vision_model", _record_vision)
+    monkeypatch.setattr(models_route, "is_embedding_model", _record_embedding)
+    monkeypatch.setattr(model_config_module, "detect_audio_type", _record_audio)
+    monkeypatch.setattr(
+        models_route.ModelConfig,
+        "from_identifier",
+        classmethod(_record_from_identifier),
+    )
+    monkeypatch.setattr(models_route, "_get_max_position_embeddings", lambda _: 4096)
+    monkeypatch.setattr(models_route, "_get_model_size_bytes", lambda *_args, **_kw: 0)
+
+    result = asyncio.run(
+        models_route.get_model_config(
+            model_name = "org/model",
+            hf_token = None,
+            current_subject = "test-subject",
+        )
+    )
+
+    assert result.model_name == "Org/Model"
+    assert calls["load_model_defaults"] == "Org/Model"
+    assert calls["is_vision_model"] == "Org/Model"
+    assert calls["is_embedding_model"] == "Org/Model"
+    assert calls["detect_audio_type"] == "Org/Model"
+    assert calls["from_identifier"] == "Org/Model"