1 files changed, 18 insertions, 1 deletions
diff --git a/lib/unitsToRanges.js b/lib/unitsToRanges.js
index e73388a..764d8f2 100644
--- a/lib/unitsToRanges.js
+++ b/lib/unitsToRanges.js
@@ -65,7 +65,7 @@ module.exports = (units, sourceAddresses) => {
       }
     })
     .flat()
-    .sort((a, b) => a - b)
+    .sort(sortNumbers)
     .reduce((acc, cur, idx, src) => {
       const curParts = cur.match(regexp)
       const prevParts = idx > 0 ? src[idx - 1].match(regexp) : null
@@ -98,3 +98,20 @@ module.exports = (units, sourceAddresses) => {
 
   return unitRanges.length ? unitRanges.join(';') : null
 }
+
+/* custom sort function where 2 goes before 1A and 1A goes before 1B */
+function sortNumbers(a, b) {
+  if (Number.isInteger(Number(a)) && Number.isInteger(Number(b))) {
+    // both are integers
+    return a - b
+  } else if (Number.isInteger(Number(a)) && !Number.isInteger(Number(b))) {
+    // a is integer but b isn't, so a goes before b
+    return  -1
+  } else if (!Number.isInteger(Number(a)) && Number.isInteger(Number(b))) {
+    // a isn't integer but b is, so a goes after b
+    return  1
+  } else {
+    // neither are integers
+    return a.localeCompare(b)
+  }
+}