Testing an Express API about ama HOT 5 CLOSED

Sounds like you've got the right idea mostly. It depends on the kind of testing you're going for though... Do you want to write unit tests or end to end tests? If you're doing unit tests, then don't worry about checking with the database and just test the logic. Unit tests should test units.

If you're doing E2E (End to End) similar to and sometimes confused (by myself) with Integration Tests, you'll want to test more of the stack (including what's in the database) and you'll probably do it a bit differently.

My opinion is that you should have both. If you can only do one, do E2E. It's a bit tougher to set up and be flaky, but you get a better picture of the health of your system. But I believe you should do both. (Just make sure to not just do unit tests, otherwise you wind up with this) :-)

Good luck!

from ama.

Oh, and thanks for the question :D

from ama.

You can also try to unit test it - http://glebbahmutov.com/blog/how-to-correctly-unit-test-express-server/

from ama.

Thanks for chiming in @bahmutov. I should have prefaced this with the fact that the last significant express server I wrote was 2 years ago, so I'm a bit out of practice :-) Hopefully the concepts I shared were sound though :-)

from ama.

tl;dr: Why not unit test just the router URL and verb?

I also had the same question and I'm working on this idea that unit tests for routers shouldn't need to spin up a server. I think you should just test the router endpoints, meaning URLs and verbs.

I do backend components for reusability reasons (not really, but I'm a former AngularJS dev so that's what I do by default), and a component has a router, repository/store, schema, ORM model, and a testfile for every one of the previous ones.
For the route, my test looks like:

var test = require('tape');
var routerInit = require('./router');
var routerInfo = routerInit();

test('/filters base path', function onTest(assert) {
  assert.plan(1);

  var path = routerInfo.path;

  assert.equals(path, '/filters');
});

test('GET /', function onTest(assert) {
  assert.plan(2);

  var route = routerInfo.router.stack[0].route;

  var routeGetMethod = route.methods.get;
  assert.equals(routeGetMethod, true);

  var routePath = route.path;
  assert.equals(routePath, '/');
});

routerInfo.router is the Express router object. You can mount a router onto another route, so the full path for the GET / in filters will be http://localhost:3000/api/filters/ where /api is the root router that mounts filterRouter via apiRouter.use(filterRouterInfo.path, filterRouterInfo.router).

Oh, and don't forget to follow above tips for end-to-end testing too!

I was going to make a tweet out of this... Don't think I will :-)

from ama.