feat(array): new undot function

src/array.test.ts

@@ -1,5 +1,5 @@
-import { describe, expect, it } from 'vitest'
-import { flattenArrayable, partition, range, toArray } from './array'
+import { describe, expect, expectTypeOf, it } from 'vitest'
+import { flattenArrayable, partition, range, toArray, undot } from './array'
 
 describe('toArray', () => {
 	it.each([
@@ -73,3 +73,65 @@ it('partition', () => {
 		),
 	).toHaveLength(6)
 })
+
+describe('undot', () => {
+	it('should undot keyed collection', () => {
+		expect(undot({
+			'name': 'Taylor',
+			'meta.foo': 'bar',
+			'meta.baz': ['boom', 'boom', 'boom'],
+			'meta.bam.boom': 'bip',
+		})).to.eql({
+			name: 'Taylor',
+			meta: {
+				foo: 'bar',
+				baz: ['boom', 'boom', 'boom'],
+				bam: {
+					boom: 'bip',
+				},
+			},
+		})
+	})
+
+	it('should undot indexed collection', () => {
+		expect(undot({
+			'foo.0': 'bar',
+			'foo.1': 'baz',
+			'foo.baz': 'boom',
+		})).to.eql({
+			foo: {
+				0: 'bar',
+				1: 'baz',
+				baz: 'boom',
+			},
+		})
+	})
+
+	it('should undot documentation example', () => {
+		expect(undot({
+			'name.first_name': 'Marie',
+			'name.last_name': 'Valentine',
+			'address.line_1': '2992 Eagle Drive',
+			'address.line_2': '',
+			'address.suburb': 'Detroit',
+			'address.state': 'MI',
+			'address.postcode': '48219',
+		})).to.eql({
+			name: {
+				first_name: 'Marie',
+				last_name: 'Valentine',
+			},
+			address: {
+				line_1: '2992 Eagle Drive',
+				line_2: '',
+				suburb: 'Detroit',
+				state: 'MI',
+				postcode: '48219',
+			},
+		})
+	})
+
+	it('is typed', () => {
+		expectTypeOf(undot({ 'foo.bar': 'baz' })).toMatchTypeOf<{ foo: { bar: string } }>()
+	})
+})

src/array.ts

@@ -207,3 +207,34 @@ export function shuffle<T>(array: T[]): T[] {
 
 	return array
 }
+
+// TODO: types, see @clickbar/dot-diver
+/**
+ * Undots the given object to a nested object.
+ */
+export function undot<T extends object>(input: T): any {
+	const result: Record<string, any> = {}
+
+	for (const key in input) {
+		const value = input[key]
+
+		if (key.includes('.')) {
+			const nestedKeys = key.split('.')
+			let currentLevel = result
+
+			for (let i = 0; i < nestedKeys.length; i++) {
+				const nestedKey = nestedKeys[i]
+
+				if (!currentLevel[nestedKey]) {
+					currentLevel[nestedKey] = i === nestedKeys.length - 1 ? value : {}
+				}
+
+				currentLevel = currentLevel[nestedKey]
+			}
+		} else {
+			result[key] = value
+		}
+	}
+
+	return result as any
+}