From 6f0d6e8abc004040497abd608e6d193af09991e8 Mon Sep 17 00:00:00 2001
From: Phan An <me@phanan.net>
Date: Sat, 14 May 2022 17:51:47 +0200
Subject: [PATCH] feat(test): add helper util tests

---
 resources/assets/js/utils/helpers.spec.ts | 35 +++++++++++++++++++++++
 resources/assets/js/utils/helpers.ts      |  2 +-
 2 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 resources/assets/js/utils/helpers.spec.ts

diff --git a/resources/assets/js/utils/helpers.spec.ts b/resources/assets/js/utils/helpers.spec.ts
new file mode 100644
index 00000000..ea9f76df
--- /dev/null
+++ b/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)
+    })
+  }
+}
diff --git a/resources/assets/js/utils/helpers.ts b/resources/assets/js/utils/helpers.ts
index 3319e848..bd268004 100644
--- a/resources/assets/js/utils/helpers.ts
+++ b/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)