Wiremock variable substitution in JSON response - json

Question

I am trying to configure Wiremock mappings to return a JSON response with a value from the request.
The request is simply
{ "clientTag": "123" }
And the mapping for it is:
{
"priority": 4,
"request": {
"method": "POST",
"urlPattern": "/test"
},
"response": {
"status": 200,
"body": "{ \"loginId\": \"${loginId}\" }",
"headers": {
"Content-Type": "application/json"
}
},
"captures" : [ {
"source" : "BODY",
"target" : "loginId",
"pattern" : "$..clientTag",
"captureGroup" : 1
} ]
}
I receive the response:
{ "loginId": "" }
while the expected one is:
{ "loginId": "123" }
If I switch to XML requests, everything works fine with the pattern <clientTag>(.*?)</clientTag>, but I would like to stick to JSON.
Unfortunately Wiremock documentation is scarce hence the question. Any ideas?
UPDATE: If someone is reading this later, you'd do best to use the transforms in the code, which are available in the later Wiremock versions.

Answer 1

This seems like a perfect use-case for OpenTable's Wiremock Body Transformer.
It can be easily integrated with the Standalone Server like this:
java -cp "wiremock-body-transformer-1.1.6.jar:wiremock-2.3.1-standalone.jar" com.github.tomakehurst.wiremock.standalone.WireMockServerRunner --verbose --extensions com.opentable.extension.BodyTransformer
This extension allows you to easily specify a variable in the request that you would want to match in the response.
{
"request": {
"method": "POST",
"urlPath": "/transform",
"bodyPatterns": [
{
"matchesJsonPath": "$.name"
}
]
},
"response": {
"status": 200,
"body": "{\"responseName\": \"$(name)\"}",
"headers": {
"Content-Type": "application/json"
},
"transformers": ["body-transformer"]
}
}
It also easily allows you to generate a random integer in the response as seen here:
{
"request": {
"method": "POST",
"urlPath": "/transform",
},
"response": {
"status": 200,
"body": "{\"randomInteger\": \"$(!RandomInteger)\"}",
"headers": {
"Content-Type": "application/json"
},
"transformers": ["body-transformer"]
}
}

Answer 2

Unless you've added an extension you haven't mentioned, this can't work - there's no "captures" element in the JSON API, and no way (without extensions) to do variable substitution in responses.

Answer 3

WireMock.Net does support this now.
When sending a request like:
{
"username": "stef"
}
And using mapping like:
{
"Request": {
"Path": {
"Matchers": [
{
"Name": "WildcardMatcher",
"Pattern": "/test"
}
]
},
"Methods": [
"post"
]
},
"Response": {
"StatusCode": 200,
"BodyAsJson": {
"path": "{{request.path}}",
"result": "{{JsonPath.SelectToken request.bodyAsJson \"username\"}}"
},
"UseTransformer": true,
"Headers": {
"Content-Type": "application/json"
}
}
}
The response will be like:
{
"path": "/test",
"result": "stef"
}
Note that this functionality is currently in preview mode, see NuGet package version 1.0.4.8-preview-01.
If you have any questions, just create an issue on this github project.