Testing error responses with ember-cli-mirage

Question

I'm reading through ember-cli-mirage's docs about creating mock responses but can't figure out how to test error responses for the exact same request. For example:

test("I can view the users", function() {
  var users = server.createList('user', 3);

  visit('/users');

  andThen(function() {
    equal( find('li').length, 3 );
    equal( find('li:first').text(), users[0].name );
  });
});

test("I can view the error if viewing the users returns an error", function() {
  // somehow set up an error response (?)   

  visit('/users');

  andThen(function() {
    equal( find('#error').length, 1 );
  });
});

It looks like the only way to form the response is in the route

this.get('/users', function(db, request) {

    if (something based on the request, i guess?) {
      return new Mirage.Response(500, {}, {message: 'Oops! Something bad happenned. :('});
    } else {
        return db.users.insert([
            {name: 'Zelda', age: 142},
            {name: 'Epona', age: 58},
        ]);
    }
});

How does mirage recommend going about doing this?

Sam Selikoff Sam Selikoff · Accepted Answer · 2015-10-07T17:58:16

Within tests, the route handlers defined in config.js are loaded, but since you have access to server you can actually overwrite those handlers.

What I do in this situation is just create an ad-hoc route handler for the error state:

test("I can view the error if viewing the users returns an error", function() {
  server.get('/users', {errors: ['there was an error']}, 404);

  visit('/users');

  andThen(function() {
    equal( find('#error').length, 1 );
  });
});

Since the server is reinstantiated for each test, this handler won't exist in other tests.

There's also a PR for an API that would allow you to write up transient route handlers, which would be useful for testing that your application could recover from an error.

Testing error responses with ember-cli-mirage

1 Answers