AngularJS: serve different responses with $httpBackend inside the same test (auto retry for example)

unit_test.coffee

# More details on https://blog.james-lafa.fr/angularjs-how-to-test-a-retry-after-http-error-with-httpbackend/

sessionCalls = 0
$httpBackend.when('POST', '/sessions').respond( (method, url, data, headers) ->
  if sessionCalls == 0
    sessionCalls++
    return [200, {"response": 1}, {}]
  else
    sessionCalls++
    return [200, {"response":0,"auth_token":"HK7i6DRncWdBmq"}, {}]
)
Backend.createSession()
$httpBackend.flush()
expect(sessionCalls).toEqual(2)
expect(Backend.isLoggedIn()).toBe(true)