Batch-Schema

Express Plugin for TypeBox Request and Response Validation

Installation

npm i @openaddresses/batch-schema

Example Usage

import express from 'express';
import Schema from '@openaddresses/batch-schema';
import { Type } from '@sinclair/typebox';

const app = express();
const schema = new Schema(express.Router(), {
    logging: true,  // Enable Morgan Logging
    limit: 50       // Body size for parsing JSON
});

app.use('/api', schema.router);

server();

async function server() {
    await schema.post('/api/:param1/:param2', {
        query: Type.Object({
            example: Type.Optional(Type.Uppercase(Type.String()))
        }),
        params: Type.Object({
            param1: Type.String(),
            param2: Type.Number(),
        }),
        body: Type.Object({
            username: Type.String(),
            password: Type.String(),
        }),
        res: Type.Object({
            token: Type.String()
        }),
        deprecated: false,
    }, (req, res) => {
        return res.json({
            token: 'I only return if the request meets the query & body schemas'
        });
    });
}

Set deprecated: true on a route schema to mark the generated OpenAPI operation as deprecated.

Request Body Validation

The body option accepts two forms.

Single TypeBox schema (legacy / shorthand)

A bare schema is treated as application/json:

await schema.post('/login', {
    body: Type.Object({
        username: Type.String(),
        password: Type.String()
    }),
    res: Type.Object({ token: Type.String() })
}, handler);

Map keyed by content-type

Provide a record where each key is a Content-Type. The value can be:

• a TSchema — body is validated against the schema
• true — body is accepted but not validated (useful for XML / CSV / binary)
• a { schema, example, examples } object — example and examples are forwarded to the OpenAPI media type for documentation

Wildcards are supported in keys: text/*, application/*, */*. An exact content-type match always wins over a wildcard.

await schema.post('/ingest', {
    body: {
        // Strict JSON validation
        'application/json': Type.Object({ name: Type.String() }),

        // Any XML accepted
        'text/xml': true,

        // Wildcard family — matches text/csv, text/plain, etc.
        'text/*': true,

        // Schema + Swagger UI examples
        'application/vnd.api+json': {
            schema: Type.Object({ data: Type.Any() }),
            example: { data: { id: '1' } },
            examples: {
                primary:   { summary: 'Primary',   value: { data: { id: '1' } } },
                secondary: { summary: 'Secondary', value: { data: { id: '2' } } }
            }
        }
    },
    res: Type.Any()
}, handler);

If a request arrives with a Content-Type that is not listed (and is not covered by a wildcard), the route responds with HTTP 400 and a Content-Type ... not supported message — the handler is not invoked.

For non-JSON content-types the body parser exposes the raw payload on req.body as a string (text/*, application/xml, application/*+xml) or a Buffer (application/octet-stream).

Optional bodies

Set bodyRequired: false to allow requests with no body / no Content-Type. When a body is sent it is still validated against the matching schema, and the OpenAPI document marks requestBody.required as false.

await schema.post('/maybe', {
    body: Type.Object({ note: Type.String() }),
    bodyRequired: false,
    res: Type.Object({ ok: Type.Boolean() })
}, handler);

API

const schema = new Schema(<router>, <opts>);

Config Option	Notes
router	Instantiated Express router to bind to
opts	Optional Opts Object
opts.schemas	Directory of named schemas

schema.api

await schema.api()

Adds a route called GET /schema which allows the caller to get a list of endpoints that the router manages as well as full schema details for every route. If your API is public we recommend enabling this feature, however if you do not wish for API routes to be published, this feature is disabled unless called.

Adds a route called GET /openapi which returns an OpenAPI / Swagger JSON Object

schema.not_found

Adds a middlware which will catch all routes that have not been defined and return a standard error object.

schema.not_found()

schema.error

Adds a middlware which will convert validation errors into a standard JSON error format. This method should be called after all routes are defined. If this method is not called, you must provide your own middleware for converting JSON Schema Validation Errors into express compatible responses.

schema.error()

schema.load

Loads and runs all routes files in a directory

schema.load(directory, config, opts)

Config Option	Notes
directory	Directory to load .js files from
config	Config option to pass to each route
opts	Optional Opts Object
opts.silent	Squelch output