class Organization {

    String name

    static hasMany = [
            users: Person,
            teams: Team
    ]

    static mapping = {
        users cascade: 'all-delete-orphan'
    }
}

class Person {

    String name
    Organization organization

    static belongsTo = [Organization, Team]
    static hasMany = [teams: Team]

    static constraints = {
    }

    def beforeDelete() {

        Team.withNewSession {
            removeFromAllTeams()
        }

        true
    }

    def removeFromAllTeams() {
        Team.where {
            members {
                id == this.id
            }
        }.each { Team team ->
            if (team.members.contains(this)) {
                team.members.remove(this)
                team.save()
            }
        }
    }
}


class Team {

    String name

    static hasMany = [members: Person]
    static belongsTo = [organization: Organization]

    static constraints = {
    }
}

SQL [n/a]; Referential integrity constraint violation: "FKGHKKY8WMH379RPMFH92T807RY: PUBLIC.TEAM_MEMBERS FOREIGN KEY(PERSON_ID) REFERENCES PUBLIC.PERSON(ID) (1)"; SQL statement:
delete from person where id=? and version=? [23503-194]; nested exception is org.h2.jdbc.JdbcSQLException: Referential integrity constraint violation: "FKGHKKY8WMH379RPMFH92T807RY: PUBLIC.TEAM_MEMBERS FOREIGN KEY(PERSON_ID) REFERENCES PUBLIC.PERSON(ID) (1)"; SQL statement:
delete from person where id=? and version=? [23503-194]

@Unroll
void "user is removed from team before deletion, runManually = #runManually"() {
    given: 'an existing org'
    Organization.withNewSession {
        def organization = new Organization(name: 'Cyberdyne Systems').save(failOnError: true)

        and: 'a person is added'
        organization.addToUsers(name: 'John Connor').save(failOnError: true)
        organization.save(failOnError: true, flush: true)

        and: 'a new team is added to the org'
        organization.addToTeams(name: 'IT').save(failOnError: true, flush: true)

        and: 'the person is added to the team'
        organization.teams.first().addToMembers(organization.users.first())
        organization.save(failOnError: true, flush: true)
    }

    and: 'the person is deleted'
    def userToDelete = Person.first()
    if (runManually) {
        userToDelete.removeFromAllTeams()
    }
    userToDelete.delete(flush: true)

    expect: 'the team has no users'
    Team.first().members.isEmpty()

    and: 'there are no more users'
    Person.count == 0

    where:
    runManually << [true, false]
}