mocha+ supertest

describe('xxx', function(){
	let signedCookies = null;
	
	//set up a route to get signedCookie
	app.get('/signedCookies', (req, res,)=>{
	    let cookie = req.query.cookie;
		res.cookie('cookiename',  cookie, {signed: true});
		res.end();
	})
	it('should xxx', done=>{
		request(app).get('/signedCookies?cookie=xxx').end((err, res)=>{
			signedCookies = res.headers['set-cookie'];
			request(app).get('/your root').set('Cookie', signedCookies).end((err, res)=>{
				....
				done();
			})
		})
	})
})

就按这个思路走