Evaluation for single select custom field

Question

For a script to run I evaluate a complex condition for

1. a status equals 'Escalated'

2. a single select 'Reviewer needed?' equals 'Yes'

3. a single select 'Service Type' equals 'Email'

4. an Assignee is Empty - (I have not tried this so far, could use help tho)

I tried

cfValues['Reviewer needed?'].value == 'Yes'

cfValues['Reviewer needed?'].getValue() == 'Yes'

cfValues['Reviewer needed?'].getValue().contains('Yes')

with dozens of combinations of single and double quotes

And it fails with

2020-06-13 10:30:30.802 ERROR - The condition: issue.status.name == "Escalated" && cfValues['Reviewer needed?']?.getValue() == "Yes" && cfValues['Service Type']?.getValue().Contains('Email')  evaluated to: ["Jira expression failed to parse: line 1, column 66:
!, -, typeof, (, IDENTIFIER, null, true, false, NUMBER, STRING, new, [ or { expected, . encountered."]

I read thru many posts and documentation including this

https://jamieechlin.atlassian.net/wiki/spaces/GRV/pages/33030148/Built-In+Scripts#Built-InScripts-PowerAssertions

PS After moving evaluations to listener script body I got

No such property: cfValues for class: Script1 on line 5

Alexey Paveliev_pgpak4 · Accepted Answer

Non-numeric custom fields are not available and need to be got via REST calls

see example for two custom fields we use: Service Type and Reviewer Needed

//getting custom field names
def customFields = get("/rest/api/2/field")
   .asObject(List)
   .body
   .findAll { (it as Map).custom } as List<Map>

def cfServiceTypeId = customFields.find { it.name == 'Service Type' }?.id
def cfReviewerNeededId = customFields.find { it.name == 'Reviewer needed?' }?.id

//getting custom fields values
def result = get("/rest/api/2/issue/${issue.key}?fields")
   .header('Content-Type', 'application/json')
   .asObject(Map)
if (result.status == 200) {
   logger.info("Success getting fields")
   serviceType = result.body.fields[cfServiceTypeId]?.value
   reviewerNeeded = result.body.fields[cfReviewerNeededId]?.value
} else {
   logger.info("Error getting fields")
}

This does not work for service desk Request Type field though!