fix: address pick issue when key not in object (#112)

* fix: address pick issue when key not in object

* fix: restrict T to a generic object and use .hasOwnProperty()

restrict the type of T to be Record<string, unknown> (thus, a generic object) and use the .hasOwnProperty() method to check if key is in obj

* test: add test for missing key and undefined property

* chore: bump version to 8.0.2 (patch)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "radash",
-  "version": "8.0.1",
+  "version": "8.0.2",
   "description": "Functional utility library - modern, simple, typed, powerful",
   "main": "dist/cjs/index.cjs",
   "module": "dist/esm/index.mjs",

src/object.ts

@@ -150,13 +150,15 @@ export const listify = <TValue, TKey extends string | number | symbol, KResult>(
  * Pick a list of properties from an object
  * into a new object
  */
-export const pick = <T, TKeys extends keyof T>(
+export const pick = <T extends Record<string, unknown>, TKeys extends keyof T>(
   obj: T,
   keys: TKeys[]
 ): Pick<T, TKeys> => {
   if (!obj) return {} as Pick<T, TKeys>
   return keys.reduce((acc, key) => {
-    return { ...acc, [key]: obj[key] }
+    if(obj.hasOwnProperty(key))
+      acc[key] = obj[key]
+    return acc;
   }, {} as Pick<T, TKeys>)
 }
 

src/tests/object.test.ts

@@ -156,6 +156,18 @@ describe('object module', () => {
       const result = _.pick({ a: 2 }, [])
       assert.deepEqual(result, {})
     })
+    test('handle key not in object', () => {
+      const result = _.pick({ a: 2, b: 3 } as any, ['c'])
+      assert.deepEqual(result, {} as any)
+    })
+    test('handle one key not in object', () => {
+      const result = _.pick({ a: 2, b: 3 } as any, ['a', 'c'])
+      assert.deepEqual(result, { a: 2 } as any)
+    })
+    test('does not ignore undefined values', () => {
+      const result = _.pick({ a: 2, b: undefined }, ['b'])
+      assert.deepEqual(result, { b: undefined })
+    })
     test('returns picked properties only', () => {
       const result = _.pick({ a: 2, b: 4 }, ['a'])
       assert.deepEqual(result, {