js/mailbox-enhancements/create-issue-on-new-comment.js

var entities = require('@jetbrains/youtrack-scripting-api/entities');

exports.rule = entities.Issue.onChange({
  title: 'Create issue on new comment',
  guard: function(ctx) {
    return ctx.issue.comments.added.isNotEmpty();
  },
  action: function(ctx) {
    var issue = ctx.issue;
    if (issue.isResolved) {
      issue.tags.forEach(function(tag) {
        if (tag.name === 'mailbox') {
          var newIssue = new entities.Issue(ctx.currentUser,
            entities.Project.findByKey(ctx.issue.project.key), ctx.issue.summary);
          newIssue.description = ctx.issue.comments.added.first().text;
          ctx.issue.comments.added.first().delete();
        }
      });
    }
    
    issue.tags.forEach(function(tag) {
      if (tag.name === 'mailbox') {
        issue.applyCommand('remove tag mailbox', ctx.currentUser);
      }
    });
  },
  requirements: {
    State: {
      type: entities.State.fieldType,
      Open: {
        name: 'Open'
      }
    }
  }
});