From 00dea40f86d7bf5932841807d05ec6c73264941e Mon Sep 17 00:00:00 2001
From: meenahoda <meena.hoda@wmfs.net>
Date: Thu, 15 Sep 2022 10:39:00 +0100
Subject: [PATCH] refactor: tidy up IsUndefined and extend tests

---
 lib/operators/is-undefined.js | 18 ++++++++----------
 test/data-test-expr-tests.js  | 13 +++++++++++++
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/lib/operators/is-undefined.js b/lib/operators/is-undefined.js
index 214c919..2820621 100644
--- a/lib/operators/is-undefined.js
+++ b/lib/operators/is-undefined.js
@@ -1,15 +1,13 @@
 'use strict'
 
 module.exports = function isUndefinedOperator (inputValue, comparisonValue, candidateStateName, cache) {
-  let nextState
-  if (comparisonValue === true) {
-    if (inputValue === undefined) {
-      nextState = candidateStateName
-    }
-  } else if (comparisonValue === false) {
-    if (inputValue !== undefined) {
-      nextState = candidateStateName
-    }
+  const isUndefined = inputValue === undefined
+
+  if (isUndefined && comparisonValue === true) {
+    return candidateStateName
+  }
+
+  if (!isUndefined && comparisonValue !== true) {
+    return candidateStateName
   }
-  return nextState
 }
diff --git a/test/data-test-expr-tests.js b/test/data-test-expr-tests.js
index 6469cb7..e5cac25 100644
--- a/test/data-test-expr-tests.js
+++ b/test/data-test-expr-tests.js
@@ -77,6 +77,19 @@ const tests = {
     [0, true, 'DefaultState'],
     [false, true, 'DefaultState']
   ],
+  IsUndefined: [
+    [undefined, true, 'NextState'],
+    ['HELLO_WORLD', false, 'NextState'],
+    [null, false, 'NextState'],
+    [0, false, 'NextState'],
+    [false, false, 'NextState'],
+
+    [undefined, false, 'DefaultState'],
+    ['HELLO_WORLD', true, 'DefaultState'],
+    [null, true, 'DefaultState'],
+    [0, true, 'DefaultState'],
+    [false, true, 'DefaultState']
+  ],
   IsBoolean: [
     ['nope', false, 'NextState'],
     [true, true, 'NextState'],