perf: reuse the natural sort collator

src/natural_sort.ts

@@ -7,9 +7,13 @@
  * file that was distributed with this source code.
  */
 
+let collator: Intl.Collator | undefined
+
 /**
  * Perform natural sorting with "Array.sort()" method
  */
 export function naturalSort(current: string, next: string) {
-  return current.localeCompare(next, undefined, { numeric: true, sensitivity: 'base' })
+  // Create the collator only when natural sorting is used, not on package import.
+  collator ??= new Intl.Collator(undefined, { numeric: true, sensitivity: 'base' })
+  return collator.compare(current, next)
 }

tests/fs_read_all.spec.ts

@@ -45,6 +45,17 @@ test.group('FS read all | relative paths', (group) => {
     assert.deepEqual(files, ['app.ts', 'config.js', 'main.json', 'server.ts'].map(normalize))
   })
 
+  test('naturally sort filenames and nested directories', async ({ assert }) => {
+    for (const file of ['item10.js', 'item2.js', 'nested10/item1.js', 'nested2/item1.js']) {
+      await outputFile(join(BASE_PATH, file), '')
+    }
+
+    assert.deepEqual(
+      await fsReadAll(BASE_PATH),
+      ['item2.js', 'item10.js', 'nested2/item1.js', 'nested10/item1.js'].map(normalize)
+    )
+  })
+
   test('recursively get a list of all files from a directory', async ({ assert, expectTypeOf }) => {
     await outputFile(join(BASE_PATH, 'app.ts'), '')
     await outputFile(join(BASE_PATH, 'app/server.ts'), '')

tests/natural_sort.spec.ts

@@ -0,0 +1,60 @@
+/*
+ * @poppinss/utils
+ *
+ * (c) Poppinss
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+import { test } from '@japa/runner'
+import { naturalSort } from '../src/natural_sort.js'
+
+test.group('natural sort', () => {
+  test('sort numbers naturally and preserve the order of equivalent strings', ({ assert }) => {
+    assert.deepEqual(['file10', 'file02', 'File2', 'filé2', 'file1'].sort(naturalSort), [
+      'file1',
+      'file02',
+      'File2',
+      'filé2',
+      'file10',
+    ])
+  })
+
+  test('match localeCompare ordering for the default locale', ({ assert }) => {
+    const values = [
+      '',
+      'a',
+      'A',
+      'ä',
+      'å',
+      'z',
+      'é',
+      'e\u0301',
+      'ß',
+      'ss',
+      'ı',
+      'i',
+      'İ',
+      'I',
+      '配置',
+      '😀',
+      '\ud800',
+      '\udfff',
+      '\u0000',
+      ...['file', 'nested/item', 'with space/'].flatMap((prefix) =>
+        ['0', '01', '1', '2', '10', '100', '١', '２'].map((number) => `${prefix}${number}.js`)
+      ),
+    ]
+    const previous = (current: string, next: string) =>
+      current.localeCompare(next, undefined, { numeric: true, sensitivity: 'base' })
+
+    for (const current of values) {
+      for (const next of values) {
+        assert.equal(Math.sign(naturalSort(current, next)), Math.sign(previous(current, next)))
+      }
+    }
+    assert.deepEqual([...values].sort(naturalSort), [...values].sort(previous))
+    assert.deepEqual([...values].reverse().sort(naturalSort), [...values].reverse().sort(previous))
+  })
+})