Validation of allele specific MAC codes

pyard/ard.py

@@ -25,6 +25,7 @@
 import re
 import sqlite3
 import sys
+from collections import Counter
 from typing import Iterable, List
 
 from . import broad_splits, smart_sort
@@ -408,8 +409,8 @@ def redux(self, glstring: str, redux_type: VALID_REDUCTION_TYPES) -> str:
                     )
 
         # Handle MAC
-        if self._config["reduce_MAC"] and self.is_mac(glstring):
-            if db.is_valid_mac_code(self.db_connection, code):
+        if self._config["reduce_MAC"] and code.isalpha():
+            if self.is_mac(glstring):  # Make sure it's a valid MAC
                 if HLA_regex.search(glstring):
                     # Remove HLA- prefix
                     allele_name = glstring.split("-")[1]
@@ -436,12 +437,7 @@ def validate(self, glstring):
         :param glstring: GL String to validate
         :return: boolean indicating success
         """
-        try:
-            return self._is_valid_gl(glstring)
-        except InvalidAlleleError as e:
-            raise InvalidTypingError(
-                f"{glstring} is not valid GL String. \n {e.message}", e
-            ) from None
+        return self._is_valid_gl(glstring)
 
     def is_XX(self, glstring: str, loc_antigen: str = None, code: str = None) -> bool:
         if loc_antigen is None or code is None:
@@ -484,12 +480,39 @@ def is_mac(self, allele: str) -> bool:
         :return: True if MAC
         """
         if ":" in allele:
-            code = allele.split(":")[1]
-            try:
+            allele_split = allele.split(":")
+            if len(allele_split) == 2:  # MACs have only single :
+                locus_antigen, code = allele_split
                 if code.isalpha():
-                    return db.is_valid_mac_code(self.db_connection, code)
-            except sqlite3.OperationalError as e:
-                print("Error: ", e)
+                    try:
+                        alleles = db.mac_code_to_alleles(self.db_connection, code)
+                        if alleles:
+                            if any(map(lambda a: ":" in a, alleles)):
+                                # allele specific antigen codes have ':' in the MAC mapping
+                                # e.g. CFWRN -> 15:01/15:98/15:157/15:202/
+                                #               15:239/15:280/15:340/35:43/35:67/35:79/35:102/35:118/35:185/51:220
+                                # Extract the antigens from the mapped alleles
+                                antigen_groups = map(lambda a: a.split(":")[0], alleles)
+                                # Rule 1: The 1st field with the most allele designations in the request is
+                                #         the 1st field of the allele code designation
+                                # Rule 2: If there is a tie in the number of alleles designations sharing the 1st field,
+                                #         the 1st field with the lowest numeric value is selected.
+                                antigen_counts = Counter(antigen_groups)
+                                # Create a table of antigen to it's counts
+                                # '15': 7
+                                # '35': 6
+                                # '51': 1
+                                # Valid antigen is the first most common one.
+                                # As it's presorted in db, also satisfies Rule 2.
+                                valid_antigen = antigen_counts.most_common(1).pop()[0]
+                                # Get antigen value 15 from 'DRB1*15'
+                                provided_antigen = locus_antigen.split("*").pop()
+                                # The MAC is only valid if the given antigen satisfies the antigen matching Rule 1 and 2
+                                return provided_antigen == valid_antigen
+                            # Valid when antigen group codes
+                            return True
+                    except sqlite3.OperationalError as e:
+                        print("Error: ", e)
         return False
 
     def is_v2(self, allele: str) -> bool:
@@ -719,8 +742,8 @@ def expand_mac(self, mac_code: str):
         :return: GL String of expanded alleles
         :rtype: str
         """
-        locus_antigen, code = mac_code.split(":")
-        if db.is_valid_mac_code(self.db_connection, code):
+        if self.is_mac(mac_code):  # Validate MAC first
+            locus_antigen, code = mac_code.split(":")
             if HLA_regex.search(mac_code):
                 locus_antigen = locus_antigen.split("-")[1]  # Remove HLA- prefix
                 return "/".join(

pyard/db.py

@@ -172,21 +172,6 @@ def alleles_to_mac_code(
     return None
 
 
-def is_valid_mac_code(connection: sqlite3.Connection, code: str) -> bool:
-    """
-    Check db if the MAC code exists.
-
-    :param connection: db connection of type sqlite.Connection
-    :param code: MAC code
-    :return: code is MAC code ?
-    """
-    mac_query = "SELECT count(alleles) from mac_codes where code = ?"
-    cursor = connection.execute(mac_query, (code,))
-    result = cursor.fetchone()
-    cursor.close()
-    return result[0] > 0
-
-
 def serology_to_alleles(connection: sqlite3.Connection, serology: str) -> List[str]:
     """
     Look up Serology in the database and return corresponding list of alleles.

scripts/pyard

@@ -155,6 +155,9 @@ if __name__ == "__main__":
     except InvalidTypingError as e:
         print("Typing Error:", e.message, file=sys.stderr)
         sys.exit(2)
+    except InvalidMACError as e:
+        print("MAC Error:", e.message, file=sys.stderr)
+        sys.exit(3)
     else:
         # Remove ard and close db connection
         del ard

tests/features/mac.feature

@@ -48,3 +48,26 @@ Feature: MAC (Multiple Allele Code)
       | A*01:01/A*01:02                      | A*01:AB       |
       | HLA-A*25:01/HLA-A*26:01              | HLA-A*25:BYHR |
       | HLA-A*02:01/HLA-A*02:09/HLA-A*02:43N | HLA-A*02:GNF  |
+
+
+  Scenario Outline: Validate allele specific antigen MACs
+
+  MAC validation rules for allele specific antigen codes:
+  - The 1st field with the most allele designations in the request is
+  the 1st field of the allele code designation
+  - If there is a tie in the number of alleles designations sharing the 1st field,
+  the 1st field with the lowest numeric value is selected.
+
+
+    Given the MAC code is <MAC>
+    When checking for validity of the MAC
+    Then the validness is <Validity>
+
+    Examples:
+      | MAC          | Validity |
+      | DRB1*07:DFJR | Invalid  |
+      | DRB1*15:DFJR | Valid    |
+      | DPB1*08:BHHE | Invalid  |
+      | DPB1*19:BHHE | Valid    |
+      | A*31:CMZEY   | Invalid  |
+      | A*02:CMZEY   | Valid    |

tests/steps/mac.py

@@ -1,6 +1,8 @@
 from behave import *
 from hamcrest import assert_that, is_
 
+from pyard.exceptions import InvalidAlleleError
+
 
 @given("the MAC code is {mac_code}")
 def step_impl(context, mac_code):
@@ -30,3 +32,17 @@ def step_impl(context):
 @then("the decoded MAC is {mac_code}")
 def step_impl(context, mac_code):
     assert_that(context.mac_code, is_(mac_code))
+
+
+@when("checking for validity of the MAC")
+def step_impl(context):
+    try:
+        context.is_valid = context.ard.validate(context.mac_code)
+    except InvalidAlleleError:
+        context.is_valid = False
+
+
+@then("the validness is {validity}")
+def step_impl(context, validity):
+    valid = validity == "Valid"
+    assert_that(context.is_valid, is_(valid))

tests/test_pyard.py

@@ -34,7 +34,7 @@
 
 import pyard
 from pyard.constants import DEFAULT_CACHE_SIZE
-from pyard.exceptions import InvalidAlleleError, InvalidMACError, InvalidTypingError
+from pyard.exceptions import InvalidAlleleError
 from pyard.misc import validate_reduction_type
 
 
@@ -135,15 +135,15 @@ def test_redux_types(self):
             validate_reduction_type("XX")
 
     def test_empty_allele(self):
-        with self.assertRaises(InvalidTypingError):
+        with self.assertRaises(InvalidAlleleError):
             self.ard.redux("A*", "lgx")
 
     def test_fp_allele(self):
-        with self.assertRaises(InvalidTypingError):
+        with self.assertRaises(InvalidAlleleError):
             self.ard.redux("A*0.123", "lgx")
 
     def test_empty_fields(self):
-        with self.assertRaises(InvalidTypingError):
+        with self.assertRaises(InvalidAlleleError):
             # : without any data
             self.ard.redux("DQA1*01:01:01:G", "lgx")
 
@@ -152,7 +152,7 @@ def test_invalid_serology(self):
         serology_a10 = self.ard.redux("A10", "lgx")
         self.assertEqual(serology_a10.split("/")[0], "A*25:01")
         # And A100 isn't a valid typing
-        with self.assertRaises(InvalidTypingError):
+        with self.assertRaises(InvalidAlleleError):
             self.ard.redux("A100", "lgx")
 
     def test_allele_duplicated(self):