Karate API Testing - Reusing variables in different scenarios in the same feature file

Question

Does Karate supports a feature where you can define a variable in a scenario and reuse it in other scenarios in the same feature file. I tried doing the same but get an error. What's the best way to reuse the variables within the same feature file ?

Scenario: Get the request Id
    * url baseUrl
    Given path 'eam'
    When method get
    Then status 200
    And def reqId = response.teams[0]resourceRequestId

Scenario: Use the above generated Id
   * url baseUrl
   * print 'From the previous Scenario: ' + reqId

Error:

Caused by: javax.script.ScriptException: ReferenceError: "reqId" is not defined in <eval> at line number 1

Answer 1

Use a Background: section. Here is an example.

EDIT: the variable if in the Background: will be re-initialized for every scenario which is standard testing framework "set up" behavior. You can use hooks such as callonce - if you want the initialization to happen only once.

If you are trying to modify a variable in one scenario and expect it to be now having that modified value when the next Scenario starts, you have misunderstood the concept of a Scenario. Just combine your steps into one Scenario, because think about it: that is the "flow" you are trying to test.

Each Scenario should be able to run stand-alone. In the future the execution order of Scenario-s could even be random or run in parallel.

Another way to explain this is - if you comment out one Scenario other ones should continue to work.

Please don't think of the Scenario as a way to "document" the important parts of your test. You can always use comments (e.g. # foo bar). Some teams assume that each HTTP "end point" should live in a separate Scenario - but this is absolutely not recommended. Look at the Hello World example itself, it deliberately shows 2 calls, a POST and a GET !

You can easily re-use code using call so you should not be worrying about whether code-duplication will be an issue.

Also - it is fine to have some code duplication, if it makes the flow easier to read. See this answer for details - and also read this article by Google.

EDIT: if you would like to read another answer that answers a similar question: https://stackoverflow.com/a/59433600/143475