[Unit Testing] express ASYNC middleware function with mocha, chai and sinon
Description
This function fetch a sessionToken sent via header. If none are provided the request is go threw without a session. If the token is valid a session is set to the request. If the token is invalid, a 403 http code is sent with a message.
The execute function implementation from the validate token service follow this interface:
/**
* @param {String} token
* @return {Promise.<Object, Error>} - ES6 promise
*/
code
middleware/setSession.js
"use strict";
import validationService from "../services/validateToken";
import KEY_HEADER from "../constants/security";
export default function(request, response, next){
let token = request.headers[KEY_HEADER] || false;
if(!token) {
request.session = false;
return next()
};
return validationService.execute(token)
.then(
session => {
request.session = session;
next()
}
)
.catch(
error => {
response.status(403).json(
{
"message": "unauthorized"
}
)
}
)
}
test
spec/middleware/setSessionSpec.js
"use strict";
// sinon mocha and chai are configured in the helper module
import helper from "../../helper";
import setSessionMiddleware from "../../../middleware/setSession"
describe(
"Set Session middleware", (done) => {
it(
"set an empty session if no headers",
() => {
let request = {
headers: {}
};
let response = {}
setSessionMiddleware(
request,
response,
() => {
request.session.should.be.false;
done();
}
)
}
);
it(
"set the session if the token is valid",
() => {
let request = {
headers: {
token: "validToken"
}
};
let response = {};
setSessionMiddleware(
request,
response,
() => {
request.session.should.be.an("object");
done();
}
)
}
);
it(
"send 403 and message if the token is invalid",
() => {
let request = {
headers: {
token: "invalid token"
}
};
let response = {
status: (code) => {
return {
json: (data) => {
return data
}
}
}
}
let statusSpy = sinon.spy(response, "status");
setSessionMiddleware(
request,
response,
() => {
// will never execute
}
)
.then(
resp => {
statusSpy.restore()
sinon.assert.calledOnce(statusSpy);
done();
}
)
}
)
}
)
Run the test
$ NODE_ENV=test mocha --require babel-core/register spec/middleware/setSessionSpec.js
Documentation:
- https://semaphoreci.com/community/tutorials/best-practices-for-spies-stubs-and-mocks-in-sinon-js
- jsdoc promise : https://github.com/jsdoc3/jsdoc/issues/509
- sinon: http://sinonjs.org/docs/
Published
11 December 2016