bpmnlint/rules/no-duplicate-sequence-flows.js

Validate your BPMN diagrams based on configurable lint rules

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

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


/**
 * A rule that verifies that there are no disconnected
 * flow elements, i.e. elements without incoming or outgoing sequence flows.
 *
 * @type { import('../lib/types.js').RuleFactory }
 */
module.exports = function() {

  const keyed = {};

  const outgoingReported = {};
  const incomingReported = {};

  function check(node, reporter) {

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

    const key = flowKey(node);

    if (key in keyed) {
      reporter.report(node.id, 'SequenceFlow is a duplicate');

      const sourceId = node.sourceRef.id;
      const targetId = node.targetRef.id;

      if (!outgoingReported[sourceId]) {
        reporter.report(sourceId, 'Duplicate outgoing sequence flows');

        outgoingReported[sourceId] = true;
      }

      if (!incomingReported[targetId]) {
        reporter.report(targetId, 'Duplicate incoming sequence flows');

        incomingReported[targetId] = true;
      }
    } else {
      keyed[key] = node;
    }
  }

  return annotateRule('no-duplicate-sequence-flows', {
    check
  });

};


// helpers /////////////////

function flowKey(flow) {
  const conditionExpression = flow.conditionExpression;

  const condition = conditionExpression ? conditionExpression.body : '';
  const source = flow.sourceRef ? flow.sourceRef.id : flow.id;
  const target = flow.targetRef ? flow.targetRef.id : flow.id;

  return source + '#' + target + '#' + condition;
}