release fix version of a ticket on transition

[Sumedh Ganta]

Hi

I am trying to release fixversions of an issue on transition(using post-function). 

I tried few answers from the community, didnt help. I am new to groovy, can someone help me fix it. 

-Sumedh

import com.atlassian.jira.bc.project.version.VersionService
import com.atlassian.jira.component.ComponentAccessor

import java.text.SimpleDateFormat

def versionService = ComponentAccessor.getComponent(VersionService)
def projectManager = ComponentAccessor.getProjectManager()

def user = ComponentAccessor.getJiraAuthenticationContext().getLoggedInUser()

def project = projectManager.getProjectByCurrentKey("project")
def version = versionService.getVersionByProjectAndName(user, project, "3.4")

def releaseDate = new SimpleDateFormat("yyyy-MM-dd").parse("2017-07-10")

def result = versionService.validateReleaseVersion(user, version, releaseDate)

if (result.isValid()) {
    versionService.releaseVersion(result)
} else {
    log.error "Could not relase version '${version.name}' due to the following errors: $result.errorCollection.errors"
}