Asserting on Payloads

Ajax payload

Before summarizing all the improvements we made to the original test, we need to discuss AJAX payloads assertions. The original list of problems listed two possible errors related to payloads

  • The AJAX call has the wrong request payload

  • The API returns the wrong payload

Both of these errors could break the app without any meaningful feedback. Cypress provides us APIs to check them.

First of all, the request payload looks like this:

{
  "user": {
    "username": "Tester92306",
    "email": "user+92306@realworld.io",
    "password": "mysupersecretpassword"
  }
}

The response payload looks like the following:

{
  "user": {
    "username": "tester92306",
    "email": "user+92306@realworld.io",
    "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZCI6IjVkNzA5NmY3MWM2YTQ5MDVjM2VhMGM3NSIsInVzZXJuYW1lIjoidGVzdGVyOTIzMDYiLCJleHAiOjE1NzI4NDczNjcsImlhdCI6MTU2NzY1OTc2N30.uT9qGkT4FPCHwkV2A_7rbRFb_YqJN3cyncdbKOC3xNY"
  }
}

We note that:

  • The username property is the same but it is converted to lowercase in the request payload.

  • The email is the same.

  • The token is a string that changes every time.

Asserting about them means checking that:

  • The request payload contains a user object that contains the data used to fill the form.

  • The response payload contains both the email and the username.is a string that’s 200-210 characters long (a JSON Web Token).

Do we need to verify whether the token is syntactically correct? Well, we should really be asking if the front-end app parses and uses the token, and does the front-end break if the token is not valid? If the answer is yes, assert about it! Otherwise, assertions are not necessary!

Starting from the most recent test:

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