My app manage Email campaigns that we can close only if all related messages are sent.

// CampaignEntity
class CampaignEntity {
  id: number;
  messages: MessageEntity[];
  status: 'CLOSED' | 'OPEN'
}

// MessageEntity
class MessageEntity{
  id: number;
  status: 'DRAFT' | 'WAITING' | 'SENT'
}

// Allow if campaign has no messages
can(Close, CampaignEntity, {
  messages: { $size: 0 },
});

// Allow if every message status is SENT
can(Close, CampaignEntity, {
  messages: { /* all messages have status === 'SENT' */ },
});

If $not had been a valid operator, I would have used this:

can(Close, CampaignEntity, {
  messages: {
    $not: { $elemMatch: { status: { $ne: 'SENT' } } },
  },
});

My app manage Email campaigns that we can close only if all related messages are sent.

// CampaignEntity
class CampaignEntity {
  id: number;
  messages: MessageEntity[];
  status: 'CLOSED' | 'OPEN'
}

// MessageEntity
class MessageEntity{
  id: number;
  status: 'DRAFT' | 'WAITING' | 'SENT'
}

// Allow if campaign has no messages
can(Close, CampaignEntity, {
  messages: { $size: 0 },
});

// Allow if every message status is SENT
can(Close, CampaignEntity, {
  messages: { /* all messages have status === 'SENT' */ },
});

If $not had been a valid operator, I would have used this:

can(Close, CampaignEntity, {
  messages: {
    $not: { $elemMatch: { status: { $ne: 'SENT' } } },
  },
});

• typescript
• nestjs
• casl

1 Answer 1

You have few options:

1. Add $not operator and use custom conditions matcher - https://casl.js.org/v6/en/advanced/customize-ability#extend-conditions-with-custom-operators
2. use combination of can and cannot. Allow to close campaigns but not those which has messages with status different from SENT

can(Close, CampaignEntity)
cannot(Close, CampaignEntity, {
  messages: { 
    $elemMatch: { 
      status: { $ne: SENT } 
    }      
  }
})