Groovy API Response JSON object assertion

Question

API Response

[Data:[DuplicateInvoiceReference:null, RequestID:null], Error:[[Code:API.INV.005, Description:Invoice Reference is null or empty]], 
Status:3, Warning:null]

I'm going to asset the Error Object, below is my code

def responseData = jsonSlurper.parseText(responseBody)
assert responseData.Error.Description == "Invoice Reference is null or empty"

but I received assertion failed

assert responseData.Error.Description == "Invoice Reference is null or empty"
       |            |     |           |
       |            |     |           false
       |            |     [Invoice Reference is null or empty]
       |            [[Code:API.INV.005, Description:Invoice Reference is null or empty]]
       [Data:[DuplicateInvoiceReference:null, RequestID:null], Error:[[Code:API.INV.005, Description:Invoice Reference is null or empty]], Status:3, Warning:null]

Please clarify the issues in the assertion part?

Answer 1

You're reading Description as though Error were a map. It is a list.

You should be having

assert responseData.Error[0].Description == "Invoice Reference is null or empty"

You need to read Description off the first element of responseData.Error