我也许误解了Pundit的政策，但我面临着一个问题，UserPolicy与SongPolicy发生了冲突。
如果AssertUserPolicy中的语句时忽略了SongPolicy中的内容，会发生什么情况：

Pundit::NotAuthorizedError in SongsController#edit 

not allowed to edit? this User

  def authorization
    authorize Current.user
  end

这个问题是在为用户引入新角色后出现的，但我认为我可能没有正确配置它，出于某种原因，在SongsController中只查看UserPolicy来Assert授权。
我有两个控制器检查用户是否登录（require_user_logged_in），另一个控制器检查Pundit的策略（authorization）：
第一次
authorization方法如下所示：

def authorization
    authorize Current.user
  end

有一个应用程序级别的策略类ApplicationPolicy：

# frozen_string_literal: true

class ApplicationPolicy
  attr_reader :user, :params, :record

  # Allows params to be part of policies.
  def initialize(context, record)
    if context.is_a?(Hash)
      @user = context[:user]
      @params = context[:params]
    else
      @user = context
      @params = {}
    end
    @record = record
  end

  def index?
    false
  end

  def show?
    false
  end

  def create?
    false
  end

  def new?
    create?
  end

  def update?
    false
  end

  def edit?
    update?
  end

  def destroy?
    false
  end

  class Scope
    def initialize(user, scope)
      @user = user
      @scope = scope
    end

    def resolve
      raise NotImplementedError, "You must define #resolve in #{self.class}"
    end

    private

    attr_reader :user, :scope
  end
end

UserPolicy保护用户视图：

class UserPolicy < ApplicationPolicy
  class Scope < Scope
  end

  def index?
    user.has_role?(:admin)
  end

  def show?
    # Access if admin or the same user only.
    user.has_role?(:admin) || is_same_user?
  end

  def create?
    index?
  end

  def new?
    create?
  end

  def update?
    index? || is_same_user?
  end

  def edit?
    update? # This is called when accessing a view for `SongsController`.
  end

  def destroy?
    index? || is_same_user? 
  end

  def delete?
    destroy?
  end

  private

  # Used to keep a user from editing another.
  # Admins should be allowed to edit all users.
  def is_same_user?
    # Check if user being accessed is the one being logged in.
    params[:id].to_s == Current.user.username.to_s
  end
end

而SongPolicy：

class SongPolicy < ApplicationPolicy
  class Scope < Scope
  end

  def index?
  end

  def show?
  end

  def create?
    user.has_role?(:admin) || user.has_role?(:collaborator) # This is ignored.
  end

  def new?
    create?
  end

  def update?
    create?
  end

  def edit?
    create?
  end

  def destroy?
    user.has_role?(:admin)
  end

  def delete?
    destroy?
  end
end

不知道还有什么可以尝试在这里，我敢肯定我错过了一些东西，如果有人更多的知识Maven可以让我知道他们的想法，为什么一个政策的声明可以泄漏到另一个，这将是非常有帮助的。