[#319] Add cached fixture feature

Signed-off-by: a.berezin <a.berezin@yadro.com>

src/frostfs_testlib/resources/optionals.py

@@ -16,11 +16,10 @@ OPTIONAL_NODE_UNDER_LOAD = os.getenv("OPTIONAL_NODE_UNDER_LOAD")
 OPTIONAL_FAILOVER_ENABLED = str_to_bool(os.getenv("OPTIONAL_FAILOVER_ENABLED", "true"))
 
 # Set this to True to disable background load. I.E. node which supposed to be stopped will not be actually stopped.
-OPTIONAL_BACKGROUND_LOAD_ENABLED = str_to_bool(
-    os.getenv("OPTIONAL_BACKGROUND_LOAD_ENABLED", "true")
-)
+OPTIONAL_BACKGROUND_LOAD_ENABLED = str_to_bool(os.getenv("OPTIONAL_BACKGROUND_LOAD_ENABLED", "true"))
 
 # Set this to False for disable autouse fixture like node healthcheck during developing time.
-OPTIONAL_AUTOUSE_FIXTURES_ENABLED = str_to_bool(
-    os.getenv("OPTIONAL_AUTOUSE_FIXTURES_ENABLED", "true")
-)
+OPTIONAL_AUTOUSE_FIXTURES_ENABLED = str_to_bool(os.getenv("OPTIONAL_AUTOUSE_FIXTURES_ENABLED", "true"))
+
+# Use cache for fixtures with @cachec_fixture decorator
+OPTIONAL_CACHE_FIXTURES = str_to_bool(os.getenv("OPTIONAL_CACHE_FIXTURES", "false"))

src/frostfs_testlib/testing/test_control.py

@@ -1,13 +1,16 @@
 import inspect
 import logging
+import os
 from functools import wraps
 from time import sleep, time
 from typing import Any
 
+import yaml
 from _pytest.outcomes import Failed
 from pytest import fail
 
 from frostfs_testlib import reporter
+from frostfs_testlib.resources.common import ASSETS_DIR
 from frostfs_testlib.utils.func_utils import format_by_args
 
 logger = logging.getLogger("NeoLogger")
@@ -128,6 +131,42 @@ def run_optionally(enabled: bool, mock_value: Any = True):
     return deco
 
 
+def cached_fixture(enabled: bool):
+    """
+    Decorator to cache fixtures.
+    MUST be placed after @pytest.fixture and before @allure decorators.
+
+    Args:
+    enabled: if true, decorated func will be cached.
+    """
+
+    def deco(func):
+        @wraps(func)
+        def func_impl(*a, **kw):
+            # TODO: *a and *kw should be parsed to some kind of hashsum and used in filename to prevent cache load from different parameters
+            cache_file = os.path.join(ASSETS_DIR, f"fixture_cache_{func.__name__}.yml")
+
+            if enabled and os.path.exists(cache_file):
+                with open(cache_file, "r") as cache_input:
+                    return yaml.load(cache_input, Loader=yaml.Loader)
+
+            result = func(*a, **kw)
+
+            if enabled:
+                with open(cache_file, "w") as cache_output:
+                    yaml.dump(result, cache_output)
+            return result
+
+        # TODO: cache yielding fixtures
+        @wraps(func)
+        def gen_impl(*a, **kw):
+            raise NotImplementedError("Not implemented for yielding fixtures")
+
+        return gen_impl if inspect.isgeneratorfunction(func) else func_impl
+
+    return deco
+
+
 def wait_for_success(
     max_wait_time: int = 60,
     interval: int = 1,