[Refactor] order: use object.groupby

Author: ljharb

Diff for: package.json

@@ -114,6 +114,7 @@
     "is-glob": "^4.0.3",
     "minimatch": "^3.1.2",
     "object.fromentries": "^2.0.6",
+    "object.groupby": "^1.0.0",
     "object.values": "^1.1.6",
     "resolve": "^1.22.3",
     "semver": "^6.3.1",

Diff for: src/rules/order.js

@@ -2,6 +2,7 @@
 
 import minimatch from 'minimatch';
 import includes from 'array-includes';
+import groupBy from 'object.groupby';
 
 import importType from '../core/importType';
 import isStaticRequire from '../core/staticRequire';
@@ -325,13 +326,7 @@ function getSorter(alphabetizeOptions) {
 }
 
 function mutateRanksToAlphabetize(imported, alphabetizeOptions) {
-  const groupedByRanks = imported.reduce(function (acc, importedItem) {
-    if (!Array.isArray(acc[importedItem.rank])) {
-      acc[importedItem.rank] = [];
-    }
-    acc[importedItem.rank].push(importedItem);
-    return acc;
-  }, {});
+  const groupedByRanks = groupBy(imported, (item) => item.rank);
 
   const sorterFn = getSorter(alphabetizeOptions);