fix: Handle case where different strings with leading zeros have the …

…same length Before: naturalCompare('a0a00a', 'a00a0a') === 0 Now: naturalCompare('a0a00a', 'a00a0a') < 0
nwoltman · Jan 21, 2020 · 7d5a4ae · 7d5a4ae
1 parent 9263689
commit 7d5a4ae
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/natural-compare.js b/natural-compare.js
@@ -19,6 +19,7 @@ function naturalCompare(a, b, opts) {
   let indexA = 0;
   let indexB = 0;
   let alphabetIndexMap = defaultAlphabetIndexMap;
+  let firstDifferenceInLeadingZeros = 0;
 
   if (opts) {
     if (opts.caseInsensitive) {
@@ -50,6 +51,10 @@ function naturalCompare(a, b, opts) {
         charCodeB = b.charCodeAt(numStartB);
       }
 
+      if (numStartA !== numStartB && firstDifferenceInLeadingZeros === 0) {
+        firstDifferenceInLeadingZeros = numStartA - numStartB;
+      }
+
       let numEndA = numStartA;
       let numEndB = numStartB;
 
@@ -102,7 +107,7 @@ function naturalCompare(a, b, opts) {
     return -1;
   }
 
-  return lengthA - lengthB;
+  return firstDifferenceInLeadingZeros;
 }
 
 const alphabetIndexMapCache = {};

diff --git a/test/test.js b/test/test.js
@@ -147,7 +147,12 @@ describe('naturalCompare()', () => {
       ['a0a', '>', 'a00'],
       ['a0a', '>', 'a000'],
       ['a0a', '<', 'a0b'],
+      ['a0a', '<', 'a00a'],
       ['a0a', '<', 'a00b'],
+      ['a00a', '<', 'a0b'],
+      ['a00a0a', '<', 'a0a00b'],
+      ['a0a00b', '<', 'a00a0b'],
+      ['a00a0b', '>', 'a0a00b'],
     ].forEach(verify);
   });