eli-5779 fixing person level application of function

Author: eddalmond1

src/eligibility_signposting_api/services/processors/derived_values/add_days_handler.py

@@ -108,8 +108,12 @@ def _find_source_date(self, context: DerivedValueContext) -> str | None:
         if not source_attr:
             return None
 
+        # For PERSON-level attributes, look for ATTRIBUTE_TYPE == "PERSON"
+        # For TARGET-level attributes, look for ATTRIBUTE_TYPE == context.attribute_name (e.g., "COVID")
+        attribute_type_to_match = "PERSON" if context.attribute_level == "PERSON" else context.attribute_name
+
         for attribute in context.person_data:
-            if attribute.get("ATTRIBUTE_TYPE") == context.attribute_name:
+            if attribute.get("ATTRIBUTE_TYPE") == attribute_type_to_match:
                 return attribute.get(source_attr)
 
         return None

src/eligibility_signposting_api/services/processors/derived_values/base.py

@@ -9,17 +9,19 @@ class DerivedValueContext:
 
     Attributes:
         person_data: List of person attribute dictionaries
-        attribute_name: The condition/vaccine type (e.g., 'COVID', 'RSV')
+        attribute_name: The condition/vaccine type (e.g., 'COVID', 'RSV') or person attribute (e.g., 'DATE_OF_BIRTH')
         source_attribute: The source attribute to derive from (e.g., 'LAST_SUCCESSFUL_DATE')
         function_args: Arguments passed to the function (e.g., number of days)
         date_format: Optional date format string for output formatting
+        attribute_level: The level of the attribute ('TARGET' or 'PERSON')
     """
 
     person_data: list[dict[str, Any]]
     attribute_name: str
     source_attribute: str | None
     function_args: str | None
     date_format: str | None
+    attribute_level: str = "TARGET"
 
 
 class DerivedValueHandler(ABC):

src/eligibility_signposting_api/services/processors/token_processor.py

@@ -167,6 +167,7 @@ def get_derived_value(
                 source_attribute=source_attribute,
                 function_args=parsed_token.function_args,
                 date_format=parsed_token.format,
+                attribute_level=parsed_token.attribute_level,
             )
 
             return registry.calculate(

tests/unit/services/processors/test_token_processor.py

@@ -608,3 +608,47 @@ def test_non_derived_token_with_valid_target_attribute_works(self):
         result = TokenProcessor.find_and_replace_tokens(person, condition)
 
         assert result.status_text == "Last date: 20260128"
+
+    def test_person_level_attribute_with_add_days_without_explicit_source(self):
+        """Test that ADD_DAYS works on PERSON-level attributes without explicit source."""
+        person = Person(
+            [
+                {"ATTRIBUTE_TYPE": "PERSON", "DATE_OF_BIRTH": "19900327"},
+            ]
+        )
+
+        condition = Condition(
+            condition_name=ConditionName("Test"),
+            status=Status.actionable,
+            status_text=StatusText("Future date: [[PERSON.DATE_OF_BIRTH:ADD_DAYS(91)]]"),
+            cohort_results=[],
+            suitability_rules=[],
+            actions=[],
+        )
+
+        result = TokenProcessor.find_and_replace_tokens(person, condition)
+
+        # 1990-03-27 + 91 days = 1990-06-26
+        assert result.status_text == "Future date: 19900626"
+
+    def test_person_level_attribute_with_add_days_explicit_source(self):
+        """Test that ADD_DAYS works on PERSON-level attributes with explicit source."""
+        person = Person(
+            [
+                {"ATTRIBUTE_TYPE": "PERSON", "DATE_OF_BIRTH": "19900327"},
+            ]
+        )
+
+        condition = Condition(
+            condition_name=ConditionName("Test"),
+            status=Status.actionable,
+            status_text=StatusText("Future date: [[PERSON.DATE_OF_BIRTH:ADD_DAYS(91, DATE_OF_BIRTH)]]"),
+            cohort_results=[],
+            suitability_rules=[],
+            actions=[],
+        )
+
+        result = TokenProcessor.find_and_replace_tokens(person, condition)
+
+        # 1990-03-27 + 91 days = 1990-06-26
+        assert result.status_text == "Future date: 19900626"