✨ Add object.pickBy (#30)

src/object/index.js

@@ -1,5 +1,6 @@
 import assign from './assign'
 import mapValues from './mapValues'
+import pickBy from './pickBy'
 
 /**
  * Array functions.
@@ -9,4 +10,5 @@ import mapValues from './mapValues'
 export {
   assign,
   mapValues,
+  pickBy,
 }

src/object/pickBy.js

@@ -0,0 +1,22 @@
+import { lodashFpConvertOptions } from '../core/consts'
+import pickBy from 'lodash/fp/pickBy'
+import update from '../core/update'
+
+const rawPickBy = pickBy.convert(lodashFpConvertOptions)
+
+/**
+ * Creates an object composed of the object properties predicate returns truthy
+ * for. The predicate is invoked with two arguments: (value, key).
+ * @function pickBy
+ * @memberof object
+ * @param {Object} object The object to modify.
+ * @param {Array|string} path The path of the property to set.
+ * @param {function} [predicate={@link https://lodash.com/docs#identity|lodash.identity}] The function invoked per iteration.
+ * @return {Object} Returns the updated object.
+ * @example pickBy({ nested: { a: 1, b: 2, c: 3, d: 4 } }, 'nested', v => v < 3) // => { nested: { a: 1, b: 2 } }
+ * @see {@link core.update|update} for more information.
+ * @see {@link https://lodash.com/docs#pickBy|lodash.pickBy} for more information.
+ * @see {@link https://lodash.com/docs#identity|lodash.identity} for more information.
+ * @since 0.1.12
+ */
+export default update(rawPickBy)

src/object/pickBy.spec.js

@@ -0,0 +1,29 @@
+/* eslint-env node, mocha */
+import { expect } from 'chai'
+import pickBy from './pickBy'
+
+describe('PickBy', () => {
+
+  const objectOne = {
+    nested: {
+      a: 1,
+      b: 2,
+      c: 3,
+      d: 4,
+    },
+  }
+  const output = {
+    nested: {
+      a: 1,
+      b: 2,
+    },
+  }
+
+  it('should pick all matching props by value', () => {
+    expect(pickBy(objectOne, 'nested', v => v < 3)).to.be.deep.equal(output)
+  })
+
+  it('should pick all matching props by key', () => {
+    expect(pickBy(objectOne, 'nested', (v, k) => k < 'c')).to.be.deep.equal(output)
+  })
+})