feat: add transform method

CHANGELOG.md

@@ -1,5 +1,11 @@
 # drizzle-toolbelt
 
+## 1.2.0
+
+### Minor Changes
+
+- Add `transform` method with data-first and data-last overloads
+
 ## 1.1.1
 
 ### Patch Changes

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "drizzle-toolbelt",
-	"version": "1.1.1",
+	"version": "1.2.0",
 	"description": "Set of tools for drizzle-orm.",
 	"scripts": {
 		"build": "tsup --dts --dts-resolve",

src/aggregate.ts

@@ -1,4 +1,5 @@
 import get from 'lodash/get';
+import type { Prettify } from './utils';
 
 /** More performant version of Object.values */
 function extractValues<T extends object>(obj: T) {
@@ -9,8 +10,6 @@ function extractValues<T extends object>(obj: T) {
 	return values;
 }
 
-// eslint-disable-next-line @typescript-eslint/ban-types
-export type Prettify<T> = { [K in keyof T]: T[K] } & {};
 export type FlatKey<T extends Record<string, any>> = {
 	[K in keyof T]: NonNullable<T[K]> extends PropertyKey
 		? K

src/index.ts

@@ -1,2 +1,3 @@
 export { aggregate } from './aggregate';
 export { takeFirst, takeFirstOrThrow } from './take';
+export { transform } from './transform';

src/transform.test.ts

@@ -0,0 +1,91 @@
+import { describe, test, expect } from 'bun:test';
+import { transform } from './transform';
+import { aggregate } from './aggregate';
+
+describe('transform', () => {
+	test('data-first', async () => {
+		const rows = [
+			{ id: 1, name: 'salem', age: 8, post: { id: 1, title: '1' } },
+			{ id: 1, name: 'salem', age: 8, post: { id: 4, title: '4' } },
+			{ id: 2, name: 'mimo', age: 7, post: { id: 2, title: '2' } },
+			{ id: 3, name: 'tapi', age: 6, post: { id: 3, title: '3' } },
+		];
+
+		const transformed = transform({
+			rows,
+			fields: {
+				name: (row) => row.name.toUpperCase(),
+				post: (row) => ({ id: row.post.id, title: +row.post.title }),
+			},
+		});
+
+		expect(transformed).toEqual([
+			{ id: 1, name: 'SALEM', age: 8, post: { id: 1, title: 1 } },
+			{ id: 1, name: 'SALEM', age: 8, post: { id: 4, title: 4 } },
+			{ id: 2, name: 'MIMO', age: 7, post: { id: 2, title: 2 } },
+			{ id: 3, name: 'TAPI', age: 6, post: { id: 3, title: 3 } },
+		]);
+	});
+
+	test('data-last', async () => {
+		const getRows = async () => [
+			{ id: 1, name: 'salem', age: 8, post: { id: 1, title: '1' } },
+			{ id: 1, name: 'salem', age: 8, post: { id: 4, title: '4' } },
+			{ id: 2, name: 'mimo', age: 7, post: { id: 2, title: '2' } },
+			{ id: 3, name: 'tapi', age: 6, post: { id: 3, title: '3' } },
+		];
+
+		const transformed = await getRows().then(
+			transform({
+				fields: {
+					age: (row) => row.age + 1,
+				},
+			}),
+		);
+
+		expect(transformed).toEqual([
+			{ id: 1, name: 'salem', age: 9, post: { id: 1, title: '1' } },
+			{ id: 1, name: 'salem', age: 9, post: { id: 4, title: '4' } },
+			{ id: 2, name: 'mimo', age: 8, post: { id: 2, title: '2' } },
+			{ id: 3, name: 'tapi', age: 7, post: { id: 3, title: '3' } },
+		]);
+	});
+
+	test('with aggregate', async () => {
+		const getRows = async () => [
+			{ id: 1, name: 'salem', age: 8, post: { id: 1, title: '1' } },
+			{ id: 1, name: 'salem', age: 8, post: { id: 4, title: '4' } },
+			{ id: 2, name: 'mimo', age: 7, post: { id: 2, title: '2' } },
+			{ id: 3, name: 'tapi', age: 6, post: { id: 3, title: '3' } },
+		];
+
+		const transformed = await getRows()
+			.then(
+				aggregate({
+					pkey: 'id',
+					fields: { posts: 'post.id' },
+				}),
+			)
+			.then(
+				transform({
+					fields: {
+						age: (row) => row.age + 1,
+					},
+				}),
+			);
+
+		expect(transformed).toEqual([
+			{
+				id: 1,
+				name: 'salem',
+				age: 9,
+				posts: [
+					{ id: 1, title: '1' },
+					{ id: 4, title: '4' },
+				],
+			},
+			{ id: 2, name: 'mimo', age: 8, posts: [{ id: 2, title: '2' }] },
+			{ id: 3, name: 'tapi', age: 7, posts: [{ id: 3, title: '3' }] },
+		]);
+	});
+});

src/transform.ts

@@ -0,0 +1,44 @@
+import type { Prettify } from './utils';
+
+export function transform<
+	TRow extends Record<PropertyKey, any>,
+	TTransform extends Partial<{ [K in keyof TRow]: (row: TRow) => any }>,
+>(params: {
+	rows: TRow[];
+	fields: TTransform;
+}): Prettify<
+	Omit<TRow, keyof TTransform> & {
+		[K in keyof TTransform]: TTransform[K] extends (params: any) => infer Ret ? Ret : never;
+	}
+>[];
+
+export function transform<
+	TRow extends Record<PropertyKey, any>,
+	TTransform extends Partial<{ [K in keyof TRow]: (row: TRow) => any }>,
+>(params: {
+	fields: TTransform;
+}): (rows: TRow[]) => Prettify<
+	Omit<TRow, keyof TTransform> & {
+		[K in keyof TTransform]: TTransform[K] extends (params: any) => infer Ret ? Ret : never;
+	}
+>[];
+
+export function transform<
+	TRow extends Record<PropertyKey, any>,
+	TTransform extends Partial<{ [K in keyof TRow]: (row: TRow) => any }>,
+>(params: {
+	rows?: TRow[];
+	fields: TTransform;
+}) {
+	// if rows is missing, build a data-last function
+	if (params.rows === undefined) return (rows: TRow[]) => transform({ rows, ...params });
+
+	for (const row of params.rows) {
+		for (const key in params.fields) {
+			const transform = params.fields[key];
+			row[key] = transform?.(row);
+		}
+	}
+
+	return params.rows;
+}

src/utils.ts

@@ -0,0 +1,3 @@
+export type Prettify<T> = {
+	[K in keyof T]: T[K];
+} & {};