talk/services/moderation/phases/karma.js

const get = require('lodash/get');

// This phase checks to see if the user making the comment is allowed to do so
// considering their reliability (Trust) status.
module.exports = ctx => {
  const { connectors: { services: { Karma } } } = ctx;
  const trust = get(ctx, 'user.metadata.trust', null);

  if (trust !== null) {
    // If the user is not a reliable commenter (passed the unreliability
    // threshold by having too many rejected comments) then we can change the
    // status of the comment to `SYSTEM_WITHHELD`, therefore pushing the user's
    // comments away from the public eye until a moderator can manage them. This of
    // course can only be applied if the comment's current status is `NONE`,
    // we don't want to interfere if the comment was rejected.
    if (Karma.isReliable('comment', trust) === false) {
      // Add the flag related to Trust to the comment.
      return {
        status: 'SYSTEM_WITHHELD',
        actions: [
          {
            action_type: 'FLAG',
            user_id: null,
            group_id: 'TRUST',
            metadata: {
              trust,
            },
          },
        ],
      };
    }
  }
};