feat(packages/stdlib): add unique arrays util

packages/stdlib/src/arrays/unique/index.test.ts

@@ -0,0 +1,39 @@
+import { describe, it, expect } from 'vitest';
+import { unique } from '.';
+
+describe('unique', () => {
+  it('return an array with unique numbers', () => {
+    const result = unique([1, 2, 3, 3, 4, 5, 5, 6]);
+    expect(result).toEqual([1, 2, 3, 4, 5, 6]);
+  });
+
+  it('return an array with unique objects based on id', () => {
+    const result = unique(
+      [{ id: 1 }, { id: 2 }, { id: 1 }],
+      (item) => item.id,
+    );
+    expect(result).toEqual([{ id: 1 }, { id: 2 }]);
+  });
+
+  it('return the same array if all elements are unique', () => {
+    const result = unique([1, 2, 3, 4, 5]);
+    expect(result).toEqual([1, 2, 3, 4, 5]);
+  });
+
+  it('handle arrays with different types of values', () => {
+    const result = unique([1, '1', 2, '2', 2, 3, '3']);
+    expect(result).toEqual([1, '1', 2, '2', 3, '3']);
+  });
+
+  it('handle arrays with symbols', () => {
+    const sym1 = Symbol('a');
+    const sym2 = Symbol('b');
+    const result = unique([sym1, sym2, sym1]);
+    expect(result).toEqual([sym1, sym2]);
+  });
+
+  it('return an empty array when given an empty array', () => {
+    const result = unique([]);
+    expect(result).toEqual([]);
+  });
+});

packages/stdlib/src/arrays/unique/index.ts

@@ -0,0 +1,33 @@
+export type UniqueKey = string | number | symbol;
+export type Extractor<Value, Key extends UniqueKey> = (value: Value) => Key;
+
+/**
+ * @name unique
+ * @category Arrays
+ * @description Returns a new array with unique values from the original array
+ * 
+ * @param {Value[]} array - The array to filter
+ * @param {Function} [extractor] - The function to extract the value to compare
+ * @returns {Value[]} - The new array with unique values
+ * 
+ * @example
+ * unique([1, 2, 3, 3, 4, 5, 5, 6]) //=> [1, 2, 3, 4, 5, 6]
+ * 
+ * @example
+ * unique([{ id: 1 }, { id: 2 }, { id: 1 }], (a, b) => a.id === b.id) //=> [{ id: 1 }, { id: 2 }]
+ * 
+ * @since 0.0.3
+ */
+export function unique<Value, Key extends UniqueKey>(
+  array: Value[],
+  extractor?: Extractor<Value, Key>,
+) {
+  const values = new Map<Key, Value>();
+
+  for (const value of array) {
+    const key = extractor ? extractor(value) : value as any;
+    values.set(key, value);
+  }
+
+  return Array.from(values.values());
+}