bpmnlint/rules/single-blank-start-event.js

Validate your BPMN diagrams based on configurable lint rules

const {
  is
} = require('bpmnlint-utils');

const {
  annotateRule
} = require('./helper');


/**
 * A rule that checks whether not more than one blank start event
 * exists per scope.
 *
 * @type { import('../lib/types.js').RuleFactory }
 */
module.exports = function() {

  function check(node, reporter) {

    if (!is(node, 'bpmn:FlowElementsContainer')) {
      return;
    }

    const flowElements = node.flowElements || [];

    const blankStartEvents = flowElements.filter(function(flowElement) {

      if (!is(flowElement, 'bpmn:StartEvent')) {
        return false;
      }

      const eventDefinitions = flowElement.eventDefinitions || [];

      return eventDefinitions.length === 0;
    });

    if (blankStartEvents.length > 1) {
      const type = is(node, 'bpmn:SubProcess') ? 'Sub process' : 'Process';

      reporter.report(node.id, type + ' has multiple blank start events');
    }
  }

  return annotateRule('single-blank-start-event', {
    check
  });

};