Let say I have a JSON file myfile.json with this content:

{
    "vm": {
        "MyVal1": false,
        "MyVal2": true,
        "MyVal3": "some string",
    }
}

And my Jenkins pipeline looks like this:

pipeline {
    agent any

    options {
        ansiColor('xterm')
    }

    stages {
        stage('Parse VM details') {
            steps {
                echo "Read VM JSON file"
                script {
                    def props = readJSON file: 'myfile.json'
                    env.MYVAL1 = props['vm'].get("MyVal1")
                    env.MYVAL2 = props['vm'].get("MyVal2")
                    env.MYVAL3 = props['vm'].get("MyVal3")
                    echo "MyVal1 will be: ${env.MYVAL1}"
                    echo "MyVal2 will be: ${env.MYVAL2}"
                    echo "MyVal3 will be: ${env.MYVAL3}"
                }
            }
        }
    }
}

When I run the pipeline, I got this results:

[Pipeline] echo
MyVal1 will be: null
[Pipeline] echo
MyVal2 will be: true
[Pipeline] echo
MyVal3 will be: some string

So for MyVal2, I get back the boolean as true, but for MyVal1, it is always null, whatever I try. I tried env.MYVAL1 = toBoolean(props['vm'].get("MyVal1")) but it did not help.

Let say the JSON file is not too flexible, so I need to solve it in the Jenkins side. How could I make MyVal1 to appear as boolean even if it is false?