Add defaultreviewers to PR if particular change in a specific json file usinh hook

[Dirlau Andrei]

Hello, I'm trying to add default reviewers to a PR opened just if a field in a json is modified.

Until now i figured out just the first condition: to add defaultreviewers if a change is made in that particular file. But i will also need to somehow parse that .json diff and check if that particular field was changed. 

My code in repository events:

import com.atlassian.bitbucket.hook.HookResponse
import com.atlassian.bitbucket.repository.RefChange
import com.atlassian.bitbucket.repository.Repository

def pullRequest = event.pullRequest

if(pullRequest.pathsMatch("glob:myfile.json", pullRequest.getCommits())){
       return true
}else{
       return false
}

the json format:

{
"repositoryName": "",
"family": "none",
"developmentBranch": "master",
"emailingList": "",
"defaultReviewersForPR": "userEmail",
"nrReviewersMustApprovePR": "1",
"buildSteps": {
      "rpm": {},
      "docker": {
             "publish": true,
             "gate": true
         },
       "helm": {
             "publish": true
        },
       "sonar": {
             "minCoverage": "0"
        }
},

I will need to add default reviewers only if the "gate" field is changed.

Is there a way to do this?

Thanks