feat(test): add helper util tests

resources/assets/js/utils/helpers.spec.ts

@@ -0,0 +1,35 @@
+import UnitTestCase from '@/__tests__/UnitTestCase'
+import { expect, it, vi } from 'vitest'
+import { arrayify, limitBy, use } from './helpers'
+
+new class extends UnitTestCase {
+  protected test () {
+    it('use() triggers a closure with a defined value', () => {
+      const mock = vi.fn()
+      use('foo', mock)
+      expect(mock).toHaveBeenCalledWith('foo')
+    })
+
+    it('use() does not trigger a closure with an undefined value', () => {
+      const mock = vi.fn()
+      use(undefined, mock)
+      expect(mock).not.toHaveBeenCalled()
+    })
+
+    it.each([
+      ['foo', ['foo']],
+      [['foo', 'bar'], ['foo', 'bar']]
+    ])('turns the parameter into an array', (input, output) => expect(arrayify(input)).toEqual(output))
+
+    it.each([
+      [2, 0, ['a', 'b']],
+      [2, 1, ['b', 'c']],
+      [1, 0, ['a']],
+      [1, 2, ['c']],
+      [0, 0, []],
+      [0, 1, []]
+    ])('takes %d elements from %d position', (count, position, result) => {
+      expect(limitBy(['a', 'b', 'c', 'd'], count, position)).toEqual(result)
+    })
+  }
+}

resources/assets/js/utils/helpers.ts

@@ -12,4 +12,4 @@ export const arrayify = <T> (maybeArray: T | Array<T>) => ([] as Array<T>).conca
 export const noop = () => {
 }
 
-export const limitBy = <T> (arr: T[], n: number, offset: number = 0): T[] => arr.slice(offset, offset + n)
+export const limitBy = <T> (arr: T[], count: number, offset: number = 0): T[] => arr.slice(offset, offset + count)