Validata Koa

Type safe data validation and sanitization for Koa requests
(body, query, headers, params) using validata.

See validata for more details on validation functionality.

Getting started

``bash
npm i validata validata-koa
`

Basic usage

$3

`typescript
import * as Router from '@koa/router';
import * as Koa from 'koa';
import { Context } from 'koa';
import * as bodyParser from 'koa-bodyparser';
import { asNumber, isObject, isString, maybeString } from 'validata';
import validator from 'validator';
import { body, Statuses, validate } from 'validata-koa';

interface Body {
age: number;
email?: string;
name: string;
}

const bodyCheck = isObject({
age: asNumber({ min: 0, coerceMax: 120 }),
email: maybeString({ validator: validator.isEmail }),
name: isString(),
});

const app = new Koa();
app.use(bodyParser());

const router: Router = new Router();
// validate() middleware captures and formats validation issue responses
router.post('/:id', validate(), (ctx: Context) => {
// these are now strongly typed
// if age is passed in as a string, it will be converted to a number (by the asNumber() check)
const { age, email, name } = body(ctx, bodyCheck);
console.log({ age, email, name });
ctx.status = Statuses.OK;
});
app.use(router.routes());
app.use(router.allowedMethods());

app.listen(8081);
`

$3

`typescript
import * as Router from '@koa/router';
import * as Koa from 'koa';
import { Context } from 'koa';
import { asNumber, isObject, isString, maybeAsNumber } from 'validata';
import { params, query, Statuses, validate } from 'validata-koa';

interface Params {
id: number;
}

const paramsCheck = isObject({
id: asNumber({ min: 0 }),
});

interface Query {
filter: string;
page?: number;
}

const queryCheck = isObject({
filter: isString(),
page: maybeAsNumber({ min: 0 }),
});

const app = new Koa();
const router: Router = new Router();

// validate() middleware captures and formats validation issue responses
router.post('/:id', validate(), (ctx: Context) => {
// these are now strongly typed
const { id } = params(ctx, paramsCheck);
const { filter, page } = query(ctx, queryCheck);

ctx.body = { id, filter, page };
ctx.status = Statuses.OK;
});
app.use(router.routes());
app.use(router.allowedMethods());

app.listen(8081);
`

Testing it out...

`bash
curl -X POST localhost:8081/foo


status=400

{"issues":[{"path":[":","id"],"value":"foo","reason":"no-conversion","info":{"toType":"number"}}]}

curl -X POST localhost:8081/12

status=400

{"issues":[{"path":["?","filter"],"reason":"not-defined"}]}

curl -X POST localhost:8081/12?filter=test

status=200

{"id":12,"filter":"test"}

curl -X POST localhost:8081/-2?filter=test

status=400

{"issues":[{"path":[":","id"],"value":-2,"reason":"min","info":{"min":0}}]}

``

$3

... can be done in pretty much the same way