handle duplicate units when converting to ranges

2 files changed, 13 insertions, 1 deletions

diff --git a/lib/unitsToRanges.js b/lib/unitsToRanges.js
index cd572f7..e73388a 100644
--- a/lib/unitsToRanges.js
+++ b/lib/unitsToRanges.js
@@ -54,7 +54,7 @@ module.exports = (units, sourceAddresses) => {
   const existingRanges = []
 
   // adapted from https://stackoverflow.com/a/54973116/6702659
-  const formedRanges = expandedUnits
+  const formedRanges = [...new Set(expandedUnits)]
     .slice()
     .map(unit => {
       if (unit.split('-').length > 1) {
diff --git a/test/unitsToRanges.js b/test/unitsToRanges.js
index 2702b4a..7183ad1 100644
--- a/test/unitsToRanges.js
+++ b/test/unitsToRanges.js
@@ -87,5 +87,17 @@ test('units list to addr:flats', t => {
     'different prefix not merged'
   )
 
+  t.same(
+    unitsToRanges(['1', '1']),
+    '1',
+    'source duplicates removed'
+  )
+
+  t.same(
+    unitsToRanges(['1', '1-2']),
+    '1-2',
+    'source duplicates removed with range'
+  )
+
   t.end()
 })