chore: add more tests to unique function

src/utils/__tests__/unique.spec.ts

@@ -3,12 +3,20 @@ import { describe, expect, it } from 'vitest';
 import { unique } from '../unique';
 
 describe('unique', () => {
-    it('should return correct index', () => {
-        expect(unique('a', 0, ['a', 'b', 'c'])).toBeTruthy();
-        expect(unique('a', 1, ['a', 'b', 'c'])).toBeFalsy();
-        expect(unique('a', 2, ['a', 'b', 'c'])).toBeFalsy();
-        expect(unique('a', 0, ['a', 'b', 'c'])).toBeTruthy();
-        expect(unique('a', 1, ['z', 'a', 'b'])).toBeTruthy();
-        expect(unique('a', 2, ['y', 'z', 'a'])).toBeTruthy();
+    it.each([
+        { value: 'a', index: 0, arr: ['a', 'b', 'c'], result: true },
+        { value: 'a', index: 1, arr: ['a', 'b', 'c'], result: false },
+        { value: 'a', index: 2, arr: ['a', 'b', 'c'], result: false },
+        { value: 'a', index: 1, arr: ['z', 'a', 'b'], result: true },
+        { value: 'a', index: 2, arr: ['y', 'z', 'a'], result: true },
+    ])('unique($value, $index, $arr) === $result', ({ value, index, arr, result }) => {
+        expect(unique(value, index, arr)).toEqual(result);
+    });
+
+    it.each([
+        { input: ['a', 'a', 'b', 'c', 'b', 'b'], expected: ['a', 'b', 'c'] },
+        { input: [1, 2, 3, 4, 4, 5, 6, 3], expected: [1, 2, 3, 4, 5, 6] },
+    ])('should filter: $input to the unique array: $expected', ({ input, expected }) => {
+        expect(input.filter(unique)).toEqual(expected);
     });
 });

src/utils/unique.ts

@@ -1 +1,3 @@
-export const unique = <T>(value: T, index: number, arr: T[]): boolean => arr.indexOf(value) === index;
+export function unique<T>(value: T, index: number, arr: T[]): boolean {
+    return arr.indexOf(value) === index;
+}