From 24ba63907539eaf05dca26e9f1cc7c78a918654c Mon Sep 17 00:00:00 2001
From: pbashyal-nmdp <pbashyal@nmdp.org>
Date: Wed, 16 Aug 2023 09:53:03 -0500
Subject: [PATCH 1/2] Add `is_null` method to ARD

---
 pyard/ard.py        |  9 +++++++++
 tests/test_pyard.py | 14 ++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/pyard/ard.py b/pyard/ard.py
index c7e2ce1..49b16dd 100644
--- a/pyard/ard.py
+++ b/pyard/ard.py
@@ -529,6 +529,15 @@ def is_shortnull(self, allele):
         """
         return allele in self.shortnulls and self._config["reduce_shortnull"]
 
+    def is_null(self, allele):
+        """
+        Check if allele is a null allele.
+
+        @param allele: Allele to check for null
+        @return: boolean indicating whether allele is null or not
+        """
+        return allele.endswith("N") and not self.is_mac(allele)
+
     def is_exp_allele(self, allele):
         """
         Test if allele is valid as a shortening (WHO rules)
diff --git a/tests/test_pyard.py b/tests/test_pyard.py
index d7adaee..13821fb 100644
--- a/tests/test_pyard.py
+++ b/tests/test_pyard.py
@@ -186,3 +186,17 @@ def test_cache_info(self):
             another_ard._redux_allele.cache_info().maxsize, higher_cache_size
         )
         self.assertEqual(another_ard.redux.cache_info().maxsize, higher_cache_size)
+
+    def test_is_null(self):
+        # a null allele
+        allele = "A*01:01N"
+        self.assertTrue(self.ard.is_null(allele))
+        # not null allele
+        allele = "A*01:01"
+        self.assertFalse(self.ard.is_null(allele))
+        # MACs ending with N shouldn't be called as Nulls
+        allele = "A*01:MN"
+        self.assertFalse(self.ard.is_null(allele))
+        # MACs shouldn't be called as Nulls
+        allele = "A*01:AB"
+        self.assertFalse(self.ard.is_null(allele))

From 606404b5b000f27c7788dafee38da8edf09e0397 Mon Sep 17 00:00:00 2001
From: pbashyal-nmdp <pbashyal@nmdp.org>
Date: Wed, 16 Aug 2023 15:55:08 -0500
Subject: [PATCH 2/2] Added msg to test validation

---
 tests/test_pyard.py | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/tests/test_pyard.py b/tests/test_pyard.py
index 13821fb..0dcf87a 100644
--- a/tests/test_pyard.py
+++ b/tests/test_pyard.py
@@ -190,13 +190,18 @@ def test_cache_info(self):
     def test_is_null(self):
         # a null allele
         allele = "A*01:01N"
-        self.assertTrue(self.ard.is_null(allele))
+        self.assertTrue(self.ard.is_null(allele), msg="A Null Allele")
         # not null allele
         allele = "A*01:01"
-        self.assertFalse(self.ard.is_null(allele))
+        self.assertFalse(self.ard.is_null(allele), msg="not null allele")
         # MACs ending with N shouldn't be called as Nulls
         allele = "A*01:MN"
-        self.assertFalse(self.ard.is_null(allele))
+        self.assertFalse(
+            self.ard.is_null(allele),
+            msg="MACs ending with N shouldn't be called as Nulls",
+        )
         # MACs shouldn't be called as Nulls
         allele = "A*01:AB"
-        self.assertFalse(self.ard.is_null(allele))
+        self.assertFalse(
+            self.ard.is_null(allele), msg="MACs shouldn't be called as Nulls"
+        )