feat(packages/stdlib): add pick object tool

packages/stdlib/src/objects/pick/index.test.ts

@@ -0,0 +1,36 @@
+import { describe, it, expect } from 'vitest';
+import { pick } from '.';
+
+describe('pick', () => {
+  it('pick a single key', () => {
+    const result = pick({ a: 1, b: 2, c: 3 }, 'a');
+
+    expect(result).toEqual({ a: 1 });
+  });
+
+  it('pick multiple keys', () => {
+    const result = pick({ a: 1, b: 2, c: 3 }, ['a', 'b']);
+
+    expect(result).toEqual({ a: 1, b: 2 });
+  });
+
+  it('return an empty object when no keys are provided', () => {
+    const result = pick({ a: 1, b: 2 }, []);
+
+    expect(result).toEqual({});
+  });
+
+  it('handle non-existent keys by setting them to undefined', () => {
+    const result = pick({ a: 1, b: 2 }, ['a', 'c'] as any);
+
+    expect(result).toEqual({ a: 1, c: undefined });
+  });
+
+  it('return an empty object if target is null or undefined', () => {
+    const emptyTarget = pick(null as any, 'a');
+    const emptyKeys = pick({ a: 1 }, null as any);
+
+    expect(emptyTarget).toEqual({});
+    expect(emptyKeys).toEqual({});
+  });
+});

packages/stdlib/src/objects/pick/index.ts

@@ -0,0 +1,38 @@
+import { isArray, type Arrayable } from '../../types';
+
+/**
+ * @name pick
+ * @category Objects
+ * @description Returns a partial copy of an object containing only the keys specified
+ * 
+ * @param {object} target - The object to pick keys from
+ * @param {Arrayable<keyof Target>} keys - The keys to pick
+ * @returns {Pick<Target, Key>} The new object with the specified keys picked
+ * 
+ * @example
+ * pick({ a: 1, b: 2, c: 3 }, 'a') // => { a: 1 }
+ * 
+ * @example
+ * pick({ a: 1, b: 2, c: 3 }, ['a', 'b']) // => { a: 1, b: 2 }
+ * 
+ * @since 0.0.3
+ */
+export function pick<Target extends object, Key extends keyof Target>(
+  target: Target,
+  keys: Arrayable<Key>
+): Pick<Target, Key> {
+  const result = {} as Pick<Target, Key>;
+
+  if (!target || !keys)
+    return result;
+
+  if (isArray(keys)) {
+    for (const key of keys) {
+      result[key] = target[key];
+    }
+  } else {
+    result[keys] = target[keys];
+  }
+
+  return result;
+}