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https://github.com/JakeFenley/koa-zod-router
Build typesafe routes for Koa with ease. Utilizes Typescript, Zod, and Koa-Router to provide an easy solution to I/O validation and type inference.
https://github.com/JakeFenley/koa-zod-router
api endpoint http koa koa-router middleware nodejs router schema schema-validation server typescript validation zod
Last synced: 8 days ago
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Build typesafe routes for Koa with ease. Utilizes Typescript, Zod, and Koa-Router to provide an easy solution to I/O validation and type inference.
- Host: GitHub
- URL: https://github.com/JakeFenley/koa-zod-router
- Owner: JakeFenley
- License: mit
- Created: 2023-01-11T08:39:24.000Z (almost 2 years ago)
- Default Branch: main
- Last Pushed: 2024-10-01T22:19:28.000Z (about 2 months ago)
- Last Synced: 2024-11-07T00:55:21.227Z (10 days ago)
- Topics: api, endpoint, http, koa, koa-router, middleware, nodejs, router, schema, schema-validation, server, typescript, validation, zod
- Language: TypeScript
- Homepage:
- Size: 415 KB
- Stars: 56
- Watchers: 1
- Forks: 3
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Security: SECURITY.md
Awesome Lists containing this project
README
# ⚡ koa-zod-router ⚡
Inspired by koa-joi-router, this package aims to provide a similar feature-set while leveraging Zod and Typescript to create typesafe routes and middlewares with built in I/O validation.
[](https://coveralls.io/github/JakeFenley/koa-zod-router?branch=main)
[zod]: https://github.com/colinhacks/zod
[coercion]: https://zod.dev/?id=coercion-for-primitives
[koa-bodyparser]: https://github.com/koajs/bodyparser
[formidable]: https://github.com/node-formidable/formidable
[@koa/router]: https://github.com/koajs/router
## 🔥 Features:
- Input/output validation and typesafety using [zod][]
- Body parsing using [koa-bodyparser][]
- Multipart parsing using [formidable][]
- Wraps [@koa/router][], providing the same API but with typesafety and validation.
- Custom validation error handling support
- RegExp path support
- CJS and ESM support
## 🚀 Install
```sh
npm install koa-zod-router
```
## 🚦 Quickstart
`index.ts:`
```js
import Koa from 'koa';
import zodRouter from 'koa-zod-router';
import { z } from 'zod';
const app = new Koa();
const router = zodRouter();
router.register({
name: 'example',
method: 'post',
path: '/post/:id',
handler: async (ctx, next) => {
const { foo } = ctx.request.body;
ctx.body = { hello: 'world' };
await next();
},
validate: {
params: z.object({ id: z.coerce.number() }),
body: z.object({ foo: z.number() }),
response: z.object({ hello: z.string() }),
},
});
app.use(router.routes());
app.listen(3000, () => {
console.log('app listening on http://localhost:3000');
});
```
### Importing/Exporting routes
Most likely you'll want to seperate your routes into seperate files, and register them somewhere in your app's initialization phase. To do this you can use the helper function createRouteSpec and specify the route's properties.
`get-user.ts:`
```js
import { createRouteSpec } from 'koa-zod-router';
import { z } from 'zod';
export const getUserRoute = createRouteSpec({
method: 'get',
path: '/user/:id',
handler: (ctx) => {
ctx.body = {
/* payload here */
};
},
validate: {
params: z.object({ id: z.coerce.number() }),
response: z.object({
/* validation here */
}),
},
});
```
`index.ts:`
```js
import zodRouter from 'koa-zod-router';
import { getUserRoute } from './get-user.ts';
const router = zodRouter();
router.register(getUserRoute);
```
### Adding state to routes
zodRouter accepts a type parameter for adding types to `ctx.state`, as well as providing a helper function used creating routes and middlewares with state types.
`route-state.ts:`
```js
import { routerSpecFactory } from 'koa-zod-router';
export type UserState = {
user: {
username: string;
email: string;
id: number;
};
};
export const specFactory = routerSpecFactory();
```
`auth-middleware.ts:`
```js
import { z } from 'zod';
import { specFactory } from './route-state';
export const authMiddleware = specFactory.createUseSpec({
handler: async (ctx, next) => {
// ... validate the session token
// setting state is now typesafe
ctx.state.user = {
username: 'johndoe',
email: '[email protected]',
id: 1,
};
await next();
},
validate: {
// validation fails if `x-session-token` is not set in the HTTP request headers
headers: z.object({ 'x-session-token': z.string() }),
},
});
```
`get-user.ts:`
```js
import { z } from 'zod';
import { specFactory } from './route-state';
export const getUserRoute = specFactory.createRouteSpec({
method: 'get',
path: '/user/:id',
handler: async (ctx) => {
//.. our route has access to the ctx.state.user types now
ctx.state.user;
},
validate: {
/* validation here */
},
});
```
`index.ts:`
```js
import zodRouter from 'koa-zod-router';
import { UserState } from './router-state';
import { authMiddleware } from './auth-middleware';
import { getUserRoute } from './get-user';
const router = zodRouter();
router.use(authMiddleware);
router.register(getUserRoute);
```
### Exposing validation errors to the client
By default validation errors will respond with either a generic 400 or 500 error depending on whether the validation fails from the sent fields in the request, or if there is an issue in the response body.
To enable ZodErrors being exposed to the client simply use the following config:
```js
const router = zodRouter({
zodRouter: { exposeRequestErrors: true, exposeResponseErrors: true },
});
```
### Type coercion
When dealing with route parameters, query strings, and headers the incoming data will be parsed as strings to begin with. From a validation standpoint this can potentially be painful to deal with when dealing with things like `Date` in javascript. Luckily [zod] has a built in [coercion] method attached to its primitive data types to solve this!
**convert a route parameter to a number:**
```js
router.register({
path: '/users/:id',
method: 'get',
handler: async (ctx) => {
console.log(typeof ctx.request.params.id);
// 'number'
},
validate: {
params: z.object({ id: z.coerce.number() }),
},
});
```
### Dealing with dates
As mentioned above type coercion can be very useful in a lot of situations, especially when dealing with dates. Since `Date` cannot be passed directly into JSON we must convert both the data received and the data being sent back to the client. Avoid using `z.date()` in your schemas as these will result in validation errors. Instead use `z.coerce.date()` for input data, and `z.string()` (or your choice of primitive data-type) for output.
```js
router.register({
path: '/date',
method: 'post',
handler: async (ctx) => {
const { date } = ctx.request.body;
console.log(date instanceof Date);
// true
ctx.body = {
date: date.toISOString(),
};
},
validate: {
body: z.object({ date: z.coerce.date() }), // converts received string or number into date object
response: z.object({ date: z.string() }),
},
});
```
### Dealing with files
koa-zod-router uses [formidable] for any requests received with the `Content-Type` header set to `multipart/*`.
This functionality is disabled by default, to enable this functionality create an instance of zodRouter and pass in `{ zodRouter: { enableMultipart: true } }` as your config. Then to validate files utilize the helper function `zFile`.
```js
import zodRouter, { zFile } from 'koa-zod-router';
const fileRouter = zodRouter({ zodRouter: { enableMultipart: true } });
fileRouter.register({
path: '/uploads',
method: 'post',
handler: async (ctx) => {
const { file_one, multiple_files } = ctx.request.files;
//...
},
validate: {
body: z.object({ hello: z.string() }),
files: z.object({
file_one: zFile(),
multiple_files: z.array(zFile()).or(zFile()),
}),
},
});
```
## Custom Validation Error Handling
`koa-zod-router` allows users to implement router-wide error handling or route specific error handling.
### Router-wide error handling
By passing a function `validationErrorHandler` into `zodRouter` options you can execute an error handler that occurs immediately after the validation-middleware does it's thing.
```js
import { ValidationErrorHandler } from 'koa-zod-router';
const validationErrorHandler: ValidationErrorHandler = async (ctx, next) => {
if (ctx.invalid.error) {
ctx.status = 400;
ctx.body = 'hello';
} else {
await next();
}
return;
};
const router = zodRouter({
zodRouter: { exposeResponseErrors: true, validationErrorHandler },
});
```
### Route specific error handling
By enabling `continueOnError` you can bypass the default error handling done by the router's validation middleware and handle the errors the way you see fit.
```js
import zodRouter from 'koa-zod-router';
import { z } from 'zod';
const router = zodRouter();
//... create a custom error handler
router.register({
method: 'get',
path: '/foo',
handler: [
// error handler
async (ctx, next) => {
// check if an error was thrown
if (ctx.invalid.error) {
// destructure all of the ZodErrors from ctx.invalid
const { body, headers, query, params, files } = ctx.invalid;
//... handle ZodErrors
} else {
await next();
}
},
async (ctx, next) => {
// .. route handler
},
],
validate: {
continueOnError: true,
body: z.object({
foo: z.string(),
}),
},
});
```
## API Reference
[Reference](https://github.com/JakeFenley/koa-zod-router/tree/main/docs/API.md)
## Feedback
Found a bug?
Please let me know in [Issues section](https://github.com/JakeFenley/koa-zod-router/issues).
Have a question or idea?
Please let me know in [Discussions section](https://github.com/JakeFenley/koa-zod-router/discussions).
Found a vulnerability or other security issue?
Please refer to [Security policy](https://github.com/JakeFenley/koa-zod-router/blob/main/SECURITY.md).