[Refactor] move collation normalization into getSorter()

Author: forivall

src/rules/order.js

@@ -242,10 +242,18 @@ function makeOutOfOrderReport(context, imported) {
   reportOutOfOrder(context, imported, outOfOrder, 'before');
 }
 
-function getSorter(ascending) {
-  const multiplier = ascending ? 1 : -1;
+function getSorter(ascending, caseInsensitive) {
+  const multiplier = (ascending ? 1 : -1);
+  const collate = caseInsensitive
+    ? caseInsensitive === 'invert'
+      ? swapCase
+      : (s) => String(s).toLowerCase()
+    : (s) => s;
 
   return function importsSorter(importA, importB) {
+    importA = collate(importA);
+    importB = collate(importB);
+
     let result;
 
     if (importA < importB) {
@@ -281,13 +289,9 @@ function mutateRanksToAlphabetize(imported, alphabetizeOptions) {
   const groupRanks = Object.keys(groupedByRanks);
 
   const sorterFn = getSorter(alphabetizeOptions.order === 'asc');
-  const comparator =
-    alphabetizeOptions.caseInsensitive === 'invert' ? (a, b) => sorterFn(swapCase(String(a)), swapCase(String(b)))
-      : alphabetizeOptions.caseInsensitive ? (a, b) => sorterFn(String(a).toLowerCase(), String(b).toLowerCase())
-        : (a, b) => sorterFn(a, b);
   // sort imports locally within their group
   groupRanks.forEach(function(groupRank) {
-    groupedByRanks[groupRank].sort(comparator);
+    groupedByRanks[groupRank].sort(sorterFn);
   });
 
   // assign globally unique rank to each import