fixed statefulness issue with os.environ in tests

image_prediction/transformer/transformers/response.py

@@ -20,34 +20,42 @@ class ResponseTransformer(Transformer):
         return build_image_info(data)
 
 
-def get_class_specific_min_image_to_page_quotient(label):
-    return get_class_specific_quotient("REL_IMAGE_SIZE", label, "min", CONFIG.filters.image_to_page_quotient.min)
+def get_class_specific_min_image_to_page_quotient(label, table=None):
+    return get_class_specific_value(
+        "REL_IMAGE_SIZE", label, "min", CONFIG.filters.image_to_page_quotient.min, table=table
+    )
 
 
-def get_class_specific_max_image_to_page_quotient(label):
-    return get_class_specific_quotient("REL_IMAGE_SIZE", label, "max", CONFIG.filters.image_to_page_quotient.max)
+def get_class_specific_max_image_to_page_quotient(label, table=None):
+    return get_class_specific_value(
+        "REL_IMAGE_SIZE", label, "max", CONFIG.filters.image_to_page_quotient.max, table=table
+    )
 
 
-def get_class_specific_min_image_width_to_height_quotient(label):
-    return get_class_specific_quotient("IMAGE_FORMAT", label, "min", CONFIG.filters.image_width_to_height_quotient.min)
+def get_class_specific_min_image_width_to_height_quotient(label, table=None):
+    return get_class_specific_value(
+        "IMAGE_FORMAT", label, "min", CONFIG.filters.image_width_to_height_quotient.min, table=table
+    )
 
 
-def get_class_specific_max_image_width_to_height_quotient(label):
-    return get_class_specific_quotient("IMAGE_FORMAT", label, "max", CONFIG.filters.image_width_to_height_quotient.max)
+def get_class_specific_max_image_width_to_height_quotient(label, table=None):
+    return get_class_specific_value(
+        "IMAGE_FORMAT", label, "max", CONFIG.filters.image_width_to_height_quotient.max, table=table
+    )
 
 
-def get_class_specific_min_classification_confidence(label):
-    return get_class_specific_quotient("CONFIDENCE", label, "min", CONFIG.filters.min_confidence)
+def get_class_specific_min_classification_confidence(label, table=None):
+    return get_class_specific_value("CONFIDENCE", label, "min", CONFIG.filters.min_confidence, table=table)
 
 
-def get_class_specific_quotient(prefix, label, bound, fallback_value):
+def get_class_specific_value(prefix, label, bound, fallback_value, table=None):
     def fallback():
         logger.warning(f"Failed to resolve {bound} {prefix.lower().replace('_', '-')} value for class '{label}'.")
         return fallback_value
 
     assert bound in ["min", "max"]
 
-    threshold_map = parse_env_var(prefix) or {}
+    threshold_map = parse_env_var(prefix, table=table) or {}
     return threshold_map.get(label, {}).get(bound) or fallback()
 
 
@@ -121,15 +129,16 @@ def build_image_info(data: dict) -> dict:
 
 
 @lru_cache(maxsize=None)
-def parse_env_var(prefix):
-    head, tail = juxt(first, compose(list, rest))(filter(prefix, os.environ))
+def parse_env_var(prefix, table=None):
+    table = table or os.environ
+    head, tail = juxt(first, compose(list, rest))(filter(prefix, table))
     if not head:
         logger.warning(f"Found no environment variable with prefix '{prefix}'.")
     elif tail:
         logger.warning(f"Found multiple candidates for environment variable with prefix '{prefix}'.")
     else:
         try:
-            return parse_env_var_value(os.environ[head])
+            return parse_env_var_value(table[head])
         except ParsingError as err:
             logger.warning(err)
 

test/unit_tests/response_transformer_test.py

@@ -1,7 +1,7 @@
 import json
-import os
 
 import pytest
+from frozendict import frozendict
 
 from image_prediction.transformer.transformers.response import (
     get_class_specific_min_image_to_page_quotient,
@@ -19,19 +19,18 @@ def label():
 
 @pytest.fixture
 def page_quotient_threshold_map(label):
-    # TODO: suboptimal, as actual environment is used
-    os.environ["REL_IMAGE_SIZE_MAP"] = json.dumps({label: {"min": 0.1, "max": 0.2}})
-    os.environ["IMAGE_FORMAT_MAP"] = json.dumps({label: {"min": 0.5, "max": 0.4}})
-    os.environ["CONFIDENCE"] = json.dumps({label: {"min": 0.8}})
-    yield
-    for env_var in ("REL_IMAGE_SIZE_MAP", "IMAGE_FORMAT_MAP", "CONFIDENCE"):
-        os.environ.pop(env_var)
+    return frozendict(
+        {
+            "REL_IMAGE_SIZE_MAP": json.dumps({label: {"min": 0.1, "max": 0.2}}),
+            "IMAGE_FORMAT_MAP": json.dumps({label: {"min": 0.5, "max": 0.4}}),
+            "CONFIDENCE": json.dumps({label: {"min": 0.8}}),
+        }
+    )
 
 
-# FIXME: Runs correctly in isolation, but fails when other tests are run before
 def test_read_environment_vars_for_thresholds(page_quotient_threshold_map, label):
-    assert get_class_specific_min_image_to_page_quotient(label) == 0.1
-    assert get_class_specific_max_image_to_page_quotient(label) == 0.2
-    assert get_class_specific_min_image_width_to_height_quotient(label) == 0.5
-    assert get_class_specific_max_image_width_to_height_quotient(label) == 0.4
-    assert get_class_specific_min_classification_confidence(label) == 0.8
+    assert get_class_specific_min_image_to_page_quotient(label, table=page_quotient_threshold_map) == 0.1
+    assert get_class_specific_max_image_to_page_quotient(label, table=page_quotient_threshold_map) == 0.2
+    assert get_class_specific_min_image_width_to_height_quotient(label, table=page_quotient_threshold_map) == 0.5
+    assert get_class_specific_max_image_width_to_height_quotient(label, table=page_quotient_threshold_map) == 0.4
+    assert get_class_specific_min_classification_confidence(label, table=page_quotient_threshold_map) == 0.8