Writing PACT test might be quite a challenge in the beginning, as it is a new tool, and we might not be able to find much information in the web yet.

Personally, I find the PACT Google Support Group is very helpful when I encounter issues. Otherwise, sometimes I do some trial and error to solve my obstacles. Below are some quick solutions to some consumer/provider test issues that I have encountered.

Consumer Tests

Below are some scenarios when it comes to writing Body DSL for some JSON bodies.

Time stamp with certain format

Eg:  2015-05-13T06:18:06Z

Body DSL: yyyy-MM-dd’T’HH:mm:ssX

Negative integer

Eg: negative integer: -280

Body DSL: integer(-250)

Field with empty []

Eg: factory[]

Body DSL: factory([])

JSON body inside arrays

Eg: factory[{

field1 123

field2 12.5


Body DSL:


field1 integer()

field2 real()


A field which might return an empty value


“fruit”, a String which can be an empty String sometimes

Body DSL:

“fruit” (~/\w.+|^$/,”banana or apple”)

Note that we could use an or operator inside the regex. However, it is probably better to separate this into 2 test cases.

Provider Test

Unable to call API in Provider test via load balancer


API connection fails when we call an API via a URL that goes through load balancer (not sure why)


Call the API directly via the server, bypassing load balancer