@smartrecruiters/openapi-first

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Start your node REST app with designing API first!

Is it for you?

If you:
- use OpenAPI Specification 3.0 to document your REST APIs written in node.js,
- like design first approach regarding REST APIs
- want your specification to be single source of truth of your API,
- want to handle validation and parsing of requests query, path, body, content-type in a unified manner for all API endpoints,

then @smartrecruiters/openapi-first is what you are looking for!

This module initializes your API connect-style application with specification in
OpenAPI Specification 3.0 format.

How to start

Let's say you have specification in OpenAPI Specification 3.0 in spec.json:

``javascript
{
"openapi": "3.0.0",
"info": {
"version": "1.0.0",
"title": "Hello World API"
},
"paths": {
"/hello": {
"get": {
"responses": {
"200": {
"description": "Success",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Greeting"
}
}
}
}
},
"x-swagger-router-controller": "greeting/hello",
"parameters": [
{
"in": "query",
"name": "name",
"schema": {
"type": "string",
"default": "world"
}
}
]
}
}
},
"components": {
"schemas": {
"Greeting": {
"type": "object",
"properties": {
"greeting": {
"type": "string"
}
}
}
}
}
}
`

Now you can implement connect-style middleware with "business logic" in greeting/hello.js:

`javascript
module.exports = function(req, res) {
res.status(200).json({greeting: Hello, ${req.query.name}!})
}
`

Now, let's make an app.js file:
`javascript
const openApiFirst = require('@smartrecruiters/openapi-first')
const express = require('express')

// create express app
const app = express()

const spec = require('./spec.json')

// create open api specification initializer
const api = openApiFirst(app, spec)

// to enable setting default values on empty query params
api.use(require('@smartrecruiters/openapi-first/middlewares/query/defaults')())

// to link the specification with code in 'api' directory
api.use(require('@smartrecruiters/openapi-first/middlewares/controllers/by-property')({dir: __dirname}))

app.listen(8080)

`

We can now run the application:
`bash
node app
`
To verify it's working, let's hit the endpoint:
`bash
curl localhost:8080/hello?who=world
`
The response should be 200 with body:
`json
{"greeting":"Hello, world!"}
`

openapi middlewares

You can use one of the middlewares under @smartrecruiters/middlewares/* or create your own. Such middlewares will be
applied to connect-style app for each operation as they are specification and operation aware. For instance,
@smartrecruiters/middlewares/query/validate middleware will be applied to any and only operation which has query
parameters defined, passing an Error to next callback when req.query is invalid.

Currently following middlewares are available:
- request body validation,
- request body parsing (e.g. form string parameters to types specified in API documentation)
- setting default values on request body,
- query parameters validation,
- setting default query parameters values
- removing unspecified query parameters,
- path parameters validation,
- content type validation,
- routing to appropriate controller,
- oauth scopes authorization,
- error handlers (MissingRequiredScopes).

$3

Middlewares for request body, query and path validation expects schema validators in order to be created.
The recommended schema validator is @smartrecruiters/openapi-schema-validator

$3

Adding your own openapi is very simple. Let's say your operation has extension
OpenAPI Specification 3.0 Specification Extension 'x-only-admin'.
If it is set on, this will mean that only users with admin can use this method.
Assuming some preceding middleware is setting req.user.role, you can write a simple openapi middleware
that will gather information from operation object and act accordingly:
`javascript
const onlyAdminMiddleware = operation =>
(req, res, next) => {
if(operation['x-only-admin'] && req.user.role !== "admin") {
res.status(403).json("Access forbidden. For this operation, you need to have admin role")
}
return next()
}
``

Contributing

Please see our Code of conduct and Contributing guidelines

License

MIT

[npm-image]: https://img.shields.io/npm/v/@smartrecruiters/openapi-first.svg
[npm-url]: https://www.npmjs.com/package/@smartrecruiters/openapi-first
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[downloads-url]: https://www.npmjs.com/package/@smartrecruiters/openapi-first
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[node-version-url]: https://nodejs.org/en/download/
[license-url]: https://github.com/smartrecruiters/openapi-first/blob/master/LICENSE
[license-image]: https://img.shields.io/npm/l/@smartrecruiters/openapi-first.svg
[travis-url]: https://travis-ci.com/smartrecruiters/openapi-first
[travis-image]: https://api.travis-ci.com/smartrecruiters/openapi-first.svg?branch=master