Validator4Oak
Validator & Sanitizer middleware for Oak.

This module provides a middleware for Oak to validate and sanitize requests.

Compatibility: Oak v14.0.0+

Validate request query, body, form and header parameters
Sanitize request parameters
Define custom error handlers
Create custom validators and sanitizers
Stack up multiple validators and sanitizers

Import module with:

import * as mod from "@trackerforce/validator4oak@[VERSION]";
import * as mod from "https://deno.land/x/validator4oak@v[VERSION]/mod.ts";

Usage

Validate query parameters

const router = new Router();
const { query, check } = ValidatorMiddleware.createMiddleware<Context, Next>();
const { isUrl } = ValidatorFn.createValidator();

router.get('/api/v1/shorten',
  query(check('name').ifValue(isUrl())), 
  (ctx: Context) => {
    // ...
  },
);

Optional query parameters:

router.get('/api/v1/shorten',
  query(check('url').isOptional()), 
  (ctx: Context) => {
    // ...
  },
);

Validate body and form parameters

Key body parameters can be accessed using dot-path notation keys, e.g. order.number.
Since Oak v14, body request can only be consumed once, so you’ll need to use state.request_body to access it within the route.

Using body:

router.post('/checkout/v1/confirm',
  body(check('order.number').ifValue(isNumeric())),
  (ctx: Context) => {
    // ...
    const body = ctx.state.request_body; // Access the body request
    // ...
  },
);

Using form:

router.post('/checkout/v1/confirm',
  form(check('order.number').ifValue(isNumeric())), 
  (ctx: Context) => {
    // ...
    const body = ctx.state.request_body; // Access the form request
    // ...
  },
);

It’s also possible to validate array of complex objects using isArray() and * wildcard to access array elements.

router.post('/checkout/v1/confirm',
  body(
    check('order.items').ifValue(isArray()),
    check('order.items.*.sku').ifValue(isString(), hasLength({ min: 6 })),
    check('order.items.*.quantity').ifValue(isNumeric())
  ), (ctx: Context) => {
    // ...
  },
);

Validate header parameters

const { header } = ValidatorMiddleware.createMiddleware<Context, Next>();
const { isNumber } = ValidatorFn.createValidator();

router.post('/example/v1/shorten',
  header(check('x-api-key').ifValue(isNumber())), 
  (ctx: Context) => {
    // ...
  },
);

Sanitize parameters

const { escape, trim } = ValidatorSn.createSanitizer();
const { hasLength } = ValidatorFn.createValidator();

router.post('/message/v1/send',
  body(
    check('message')
      .sanitizeWith(escape(), trim())
      .ifValue(hasLength({ max: 500 }))
  ), (ctx: Context) => {
    // ...
  },
);

Testing

Use deno task test to run tests.

Check Oak compatibility

Replace the Oak version in the tests/deps.ts file to verify if middleware is compatible.

export * from "jsr:@oak/oak@[OAK_VERSION]";

Contributing

Please open an issue if you have some cool ideas to contribute.