Mock 'http' objects for testing Express, Next.js and Koa routing functions
npm install node-mocks-http
---
[![NPM version][npm-badge]][npm-url]
Mock 'http' objects for testing [Express][express-url], [Next.js][nextjs-url] and [Koa][koa-url] routing functions,
but could be used for testing any [Node.js][node-url] web server applications that have code that requires mockups of the request and response objects.
This project is available as a
[NPM package][npm-url].
``bash`
$ npm install node-mocks-http --save-dev
$ npm install @types/node @types/express --save-dev # when using TypeScript
or
`bash`
$ yarn add node-mocks-http --dev
$ yarn add @types/node @types/express --dev # when using TypeScript
After installing the package include the following in your test files:
`js`
const httpMocks = require('node-mocks-http');
Suppose you have the following Express route:
`js`
app.get('/user/:id', routeHandler);
And you have created a function to handle that route's call:
`js`
const routeHandler = function( request, response ) { ... };
You can easily test the routeHandler function with some code like
this using the testing framework of your choice:
`js
exports['routeHandler - Simple testing'] = function (test) {
const request = httpMocks.createRequest({
method: 'GET',
url: '/user/42',
params: {
id: 42
}
});
const response = httpMocks.createResponse();
routeHandler(request, response);
const data = response._getJSONData(); // short-hand for JSON.parse( response._getData() );
test.equal('Bob Dog', data.name);
test.equal(42, data.age);
test.equal('bob@dog.com', data.email);
test.equal(200, response.statusCode);
test.ok(response._isEndCalled());
test.ok(response._isJSON());
test.ok(response._isUTF8());
test.done();
};
`
The typings for TypeScript are bundled with this project. In particular, the .createRequest(), .createResponse() and .createMocks() methods are typed and are generic. Unless specified explicitly, they will be return an Express-based request/response object:
`ts
it('should handle expressjs requests', () => {
const mockExpressRequest = httpMocks.createRequest({
method: 'GET',
url: '/user/42',
params: {
id: 42
}
});
const mockExpressResponse = httpMocks.createResponse();
routeHandler(request, response);
const data = response._getJSONData();
test.equal('Bob Dog', data.name);
test.equal(42, data.age);
test.equal('bob@dog.com', data.email);
test.equal(200, response.statusCode);
test.ok(response._isEndCalled());
test.ok(response._isJSON());
test.ok(response._isUTF8());
test.done();
});
`
The expected type parameter in the mock request and response expects any type that extends the NodeJS
http.IncomingRequest interface or Fetch API Request class. This means you can also mock requests
coming from other frameworks too. An example for NextJS request will look like this:
`ts
it('should handle nextjs requests', () => {
const mockExpressRequest = httpMocks.createRequest
method: 'GET',
url: '/user/42',
params: {
id: 42
}
});
const mockExpressResponse = httpMocks.createResponse
// ... the rest of the test as above.
});
`
It is also possible to mock requests from the NextJS new AppRouter:
`ts
it('should handle nextjs app reouter requests', () => {
const mockExpressRequest = httpMocks.createRequest
method: 'GET',
url: '/user/42',
params: {
id: 42
}
});
const mockExpressResponse = httpMocks.createResponse
// ... the rest of the test as above.
});
`
`
httpMocks.createRequest(options)
Where options is an object hash with any of the following values:
| option | description | default value |
| --------------- | -------------------------------- | ------------- |
| method | request HTTP method | 'GET' |url
| | request URL | '' |originalUrl
| | request original URL | url |baseUrl
| | request base URL | url |path
| | request path | '' |params
| | object hash with params | {} |session
| | object hash with session values | undefined |cookies
| | object hash with request cookies | {} |socket
| | object hash with request socket | {} |signedCookies
| | object hash with signed cookies | undefined |headers
| | object hash with request headers | {} |body
| | object hash with body | {} |query
| | object hash with query values | {} |files
| | object hash with values | {} |
The object returned from this function also supports the Express request functions (.accepts(), .is(), .get(), .range(), etc.). Please send a PR for any missing functions.
`js`
httpMocks.createResponse(options);
Where options is an object hash with any of the following values:
| option | description | default value |
| ---------------- | ----------------------------------------------- | -------------------- |
| locals | object that contains response local variables | {} |eventEmitter
| | event emitter used by response object | mockEventEmitter |writableStream
| | writable stream used by response object | mockWritableStream |req
| | Request object being responded to | null |
> NOTE: The out-of-the-box mock event emitter included with node-mocks-http is
> not a functional event emitter and as such does not actually emit events. If you
> wish to test your event handlers you will need to bring your own event emitter.
> Here's an example:
`js
const httpMocks = require('node-mocks-http');
const res = httpMocks.createResponse({
eventEmitter: require('events').EventEmitter
});
// ...
it('should do something', function(done) {
res.on('end', function() {
assert.equal(...);
done();
});
});
// ...
`
> This is an example to send request body and trigger it's 'data' and 'end' events:
`js
const httpMocks = require('node-mocks-http');
const req = httpMocks.createRequest();
const res = httpMocks.createResponse({
eventEmitter: require('events').EventEmitter
});
// ...
it('should do something', function (done) {
res.on('end', function () {
expect(response._getData()).to.equal('data sent in request');
done();
});
route(req, res);
req.send('data sent in request');
});
function route(req, res) {
let data = [];
req.on('data', (chunk) => {
data.push(chunk);
});
req.on('end', () => {
data = Buffer.concat(data);
res.write(data);
res.end();
});
}
// ...
`
`js`
httpMocks.createMocks(reqOptions, resOptions);
Merges createRequest and createResponse. Passes given options object to eachreq
constructor. Returns an object with properties and res.
We wanted some simple mocks without a large framework.
We also wanted the mocks to act like the original framework being
mocked, but allow for setting of values before calling and inspecting
of values after calling.
We are looking for more volunteers to bring value to this project,
including the creation of more objects from the
[HTTP module][node-http-module-url].
This project doesn't address all features that must be
mocked, but it is a good start. Feel free to send pull requests,
and a member of the team will be timely in merging them.
If you wish to contribute please read our Contributing Guidelines.
Most releases fix bugs with our mocks or add features similar to the
actual Request and Response` objects offered by Node.js and extended
by Express.
See the Release History for details.
[release-notes]: https://github.com/eugef/node-mocks-http/releases
Licensed under MIT.
[npm-badge]: https://badge.fury.io/js/node-mocks-http.png
[npm-url]: https://www.npmjs.com/package/node-mocks-http
[express-url]: https://expressjs.com
[nextjs-url]: https://nextjs.org
[koa-url]: https://koajs.com
[node-url]: http://www.nodejs.org
[node-http-module-url]: http://nodejs.org/docs/latest/api/http.html