From f5efe84d1590c6d47dede3faeaa366c5012fbd0f Mon Sep 17 00:00:00 2001
From: meenahoda <meena.hoda@wmfs.net>
Date: Thu, 15 Sep 2022 10:36:48 +0100
Subject: [PATCH] refactor: tidy up IsNull and extend tests

---
 lib/operators/is-null.js     | 12 ++++++------
 test/data-test-expr-tests.js |  9 ++++++++-
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/lib/operators/is-null.js b/lib/operators/is-null.js
index ee43e33..3e52817 100644
--- a/lib/operators/is-null.js
+++ b/lib/operators/is-null.js
@@ -1,13 +1,13 @@
 'use strict'
 
 module.exports = function isNullOperator (inputValue, comparisonValue, candidateStateName, cache) {
-  let nextState
+  const isNull = inputValue === null
 
-  if (comparisonValue && inputValue === null) {
-    nextState = candidateStateName
-  } else if (!comparisonValue && inputValue !== null) {
-    nextState = candidateStateName
+  if (isNull && comparisonValue === true) {
+    return candidateStateName
   }
 
-  return nextState
+  if (!isNull && comparisonValue !== true) {
+    return candidateStateName
+  }
 }
diff --git a/test/data-test-expr-tests.js b/test/data-test-expr-tests.js
index 15a5058..6469cb7 100644
--- a/test/data-test-expr-tests.js
+++ b/test/data-test-expr-tests.js
@@ -67,14 +67,21 @@ const tests = {
   IsNull: [
     [null, true, 'NextState'],
     ['HELLO_WORLD', false, 'NextState'],
+    [undefined, false, 'NextState'],
+    [0, false, 'NextState'],
+    [false, false, 'NextState'],
 
     [null, false, 'DefaultState'],
-    ['HELLO_WORLD', true, 'DefaultState']
+    ['HELLO_WORLD', true, 'DefaultState'],
+    [undefined, true, 'DefaultState'],
+    [0, true, 'DefaultState'],
+    [false, true, 'DefaultState']
   ],
   IsBoolean: [
     ['nope', false, 'NextState'],
     [true, true, 'NextState'],
     [false, true, 'NextState'],
+
     ['nope', true, 'DefaultState'],
     [true, false, 'DefaultState'],
     [false, false, 'DefaultState']