bpmn-io · nikku · Jan 30, 2024 · Jan 25, 2024 · Jan 25, 2024 · Jan 25, 2024
diff --git a/config/all.js b/config/all.js
@@ -4,6 +4,7 @@ const allRules = [
   'event-sub-process-typed-start-event',
   'fake-join',
   'label-required',
+  'link-event',
   'no-bpmndi',
   'no-complex-gateway',
   'no-disconnected',

diff --git a/config/recommended.js b/config/recommended.js
@@ -5,6 +5,7 @@ module.exports = {
     'event-sub-process-typed-start-event': 'error',
     'fake-join': 'warn',
     'label-required': 'error',
+    'link-event': 'error',
     'no-bpmndi': 'error',
     'no-complex-gateway': 'error',
     'no-disconnected': 'error',

diff --git a/docs/rules/examples/link-event-correct.bpmn b/docs/rules/examples/link-event-correct.bpmn
@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<bpmn:definitions xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" xmlns:modeler="http://camunda.org/schema/modeler/1.0" id="Definitions_1x7j8t1" targetNamespace="http://bpmn.io/schema/bpmn" exporter="Camunda Modeler" exporterVersion="5.20.0-nightly.20240107" modeler:executionPlatform="Camunda Cloud" modeler:executionPlatformVersion="8.4.0">
+  <bpmn:process id="Process_0im3pgs" isExecutable="true">
+    <bpmn:intermediateThrowEvent id="Event_0fvzchs" name="LINK">
+      <bpmn:incoming>Flow_0w6huzu</bpmn:incoming>
+      <bpmn:linkEventDefinition id="LinkEventDefinition_0l1hwet" name="" />
+    </bpmn:intermediateThrowEvent>
+    <bpmn:startEvent id="Event_19sw7x6">
+      <bpmn:outgoing>Flow_0w6huzu</bpmn:outgoing>
+    </bpmn:startEvent>
+    <bpmn:sequenceFlow id="Flow_0w6huzu" sourceRef="Event_19sw7x6" targetRef="Event_0fvzchs" />
+    <bpmn:endEvent id="Event_17p3a4n">
+      <bpmn:incoming>Flow_1yhu2w5</bpmn:incoming>
+    </bpmn:endEvent>
+    <bpmn:intermediateCatchEvent id="Event_0hnrksg" name="LINK">
+      <bpmn:outgoing>Flow_1yhu2w5</bpmn:outgoing>
+      <bpmn:linkEventDefinition id="LinkEventDefinition_08twe44" name="" />
+    </bpmn:intermediateCatchEvent>
+    <bpmn:sequenceFlow id="Flow_1yhu2w5" sourceRef="Event_0hnrksg" targetRef="Event_17p3a4n" />
+  </bpmn:process>
+  <bpmndi:BPMNDiagram id="BPMNDiagram_1">
+    <bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="Process_0im3pgs">
+      <bpmndi:BPMNShape id="Event_00qu043_di" bpmnElement="Event_0fvzchs">
+        <dc:Bounds x="232" y="82" width="36" height="36" />
+        <bpmndi:BPMNLabel>
+          <dc:Bounds x="238" y="125" width="25" height="14" />
+        </bpmndi:BPMNLabel>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Event_1w9uhf6_di" bpmnElement="Event_0hnrksg">
+        <dc:Bounds x="372" y="82" width="36" height="36" />
+        <bpmndi:BPMNLabel>
+          <dc:Bounds x="378" y="125" width="25" height="14" />
+        </bpmndi:BPMNLabel>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Event_17p3a4n_di" bpmnElement="Event_17p3a4n">
+        <dc:Bounds x="462" y="82" width="36" height="36" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Event_19sw7x6_di" bpmnElement="Event_19sw7x6">
+        <dc:Bounds x="142" y="82" width="36" height="36" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNEdge id="Flow_0w6huzu_di" bpmnElement="Flow_0w6huzu">
+        <di:waypoint x="178" y="100" />
+        <di:waypoint x="232" y="100" />
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge id="Flow_1yhu2w5_di" bpmnElement="Flow_1yhu2w5">
+        <di:waypoint x="408" y="100" />
+        <di:waypoint x="462" y="100" />
+      </bpmndi:BPMNEdge>
+    </bpmndi:BPMNPlane>
+  </bpmndi:BPMNDiagram>
+</bpmn:definitions>
diff --git a/docs/rules/examples/link-event-correct.png b/docs/rules/examples/link-event-correct.png
diff --git a/docs/rules/examples/link-event-incorrect.bpmn b/docs/rules/examples/link-event-incorrect.bpmn
@@ -0,0 +1,78 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<bpmn:definitions xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" xmlns:modeler="http://camunda.org/schema/modeler/1.0" id="Definitions_1x7j8t1" targetNamespace="http://bpmn.io/schema/bpmn" exporter="Camunda Modeler" exporterVersion="5.20.0-nightly.20240107" modeler:executionPlatform="Camunda Cloud" modeler:executionPlatformVersion="8.4.0">
+  <bpmn:process id="Process_0im3pgs" isExecutable="true">
+    <bpmn:intermediateThrowEvent id="Event_0fvzchs" name="JUMP">
+      <bpmn:incoming>Flow_0w6huzu</bpmn:incoming>
+      <bpmn:linkEventDefinition id="LinkEventDefinition_0l1hwet" name="" />
+    </bpmn:intermediateThrowEvent>
+    <bpmn:startEvent id="Event_19sw7x6">
+      <bpmn:outgoing>Flow_0w6huzu</bpmn:outgoing>
+    </bpmn:startEvent>
+    <bpmn:sequenceFlow id="Flow_0w6huzu" sourceRef="Event_19sw7x6" targetRef="Event_0fvzchs" />
+    <bpmn:subProcess id="Activity_0jz3rxz">
+      <bpmn:intermediateCatchEvent id="Event_022ctsn" name="JUMP">
+        <bpmn:outgoing>Flow_1v2vhxj</bpmn:outgoing>
+        <bpmn:linkEventDefinition id="LinkEventDefinition_0adz8q7" name="" />
+      </bpmn:intermediateCatchEvent>
+      <bpmn:intermediateThrowEvent id="Event_0q5xos0">
+        <bpmn:incoming>Flow_1v2vhxj</bpmn:incoming>
+        <bpmn:linkEventDefinition id="LinkEventDefinition_1sut9bb" name="" />
+      </bpmn:intermediateThrowEvent>
+      <bpmn:sequenceFlow id="Flow_1v2vhxj" sourceRef="Event_022ctsn" targetRef="Event_0q5xos0" />
+    </bpmn:subProcess>
+    <bpmn:intermediateCatchEvent id="Event_0rw1f16">
+      <bpmn:outgoing>Flow_1m6xxsl</bpmn:outgoing>
+      <bpmn:linkEventDefinition id="LinkEventDefinition_00e5m7a" name="" />
+    </bpmn:intermediateCatchEvent>
+    <bpmn:endEvent id="Event_0rn7sje">
+      <bpmn:incoming>Flow_1m6xxsl</bpmn:incoming>
+    </bpmn:endEvent>
+    <bpmn:sequenceFlow id="Flow_1m6xxsl" sourceRef="Event_0rw1f16" targetRef="Event_0rn7sje" />
+  </bpmn:process>
+  <bpmndi:BPMNDiagram id="BPMNDiagram_1">
+    <bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="Process_0im3pgs">
+      <bpmndi:BPMNShape id="Event_00qu043_di" bpmnElement="Event_0fvzchs">
+        <dc:Bounds x="232" y="82" width="36" height="36" />
+        <bpmndi:BPMNLabel>
+          <dc:Bounds x="236" y="125" width="30" height="14" />
+        </bpmndi:BPMNLabel>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Event_19sw7x6_di" bpmnElement="Event_19sw7x6">
+        <dc:Bounds x="142" y="82" width="36" height="36" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Event_17pzlw3_di" bpmnElement="Event_0rw1f16">
+        <dc:Bounds x="442" y="82" width="36" height="36" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Event_0rn7sje_di" bpmnElement="Event_0rn7sje">
+        <dc:Bounds x="532" y="82" width="36" height="36" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Activity_0jz3rxz_di" bpmnElement="Activity_0jz3rxz" isExpanded="true">
+        <dc:Bounds x="200" y="190" width="278" height="150" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Event_003mg68_di" bpmnElement="Event_022ctsn">
+        <dc:Bounds x="262" y="242" width="36" height="36" />
+        <bpmndi:BPMNLabel>
+          <dc:Bounds x="265" y="285" width="30" height="14" />
+        </bpmndi:BPMNLabel>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="BPMNShape_0s0jw0v" bpmnElement="Event_0q5xos0">
+        <dc:Bounds x="372" y="242" width="36" height="36" />
+        <bpmndi:BPMNLabel>
+          <dc:Bounds x="466" y="315" width="30" height="14" />
+        </bpmndi:BPMNLabel>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNEdge id="Flow_1v2vhxj_di" bpmnElement="Flow_1v2vhxj">
+        <di:waypoint x="298" y="260" />
+        <di:waypoint x="372" y="260" />
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge id="Flow_0w6huzu_di" bpmnElement="Flow_0w6huzu">
+        <di:waypoint x="178" y="100" />
+        <di:waypoint x="232" y="100" />
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge id="Flow_1m6xxsl_di" bpmnElement="Flow_1m6xxsl">
+        <di:waypoint x="478" y="100" />
+        <di:waypoint x="532" y="100" />
+      </bpmndi:BPMNEdge>
+    </bpmndi:BPMNPlane>
+  </bpmndi:BPMNDiagram>
+</bpmn:definitions>
diff --git a/docs/rules/examples/link-event-incorrect.png b/docs/rules/examples/link-event-incorrect.png
diff --git a/docs/rules/link-event.md b/docs/rules/link-event.md
@@ -0,0 +1,20 @@
+# Link Event (link-event)
+
+A rule that checks that link events are used in accordance with the BPMN specification:
+
+* A link event must be named
+* For every link throw event there exists a matching catch event in the same scope
+
+
+Example of __incorrect__ usage for this rule:
+
+![Incorrect usage example](./examples/link-event-incorrect.png)
+
+Cf. [`link-event-incorrect.bpmn`](./examples/link-event-incorrect.bpmn).
+
+
+Example of __correct__ usage for this rule:
+
+![Correct usage example](./examples/link-event-correct.png)
+
+Cf. [`link-event-correct.bpmn`](./examples/link-event-correct.bpmn).
diff --git a/package.json b/package.json
@@ -28,7 +28,7 @@
   "license": "MIT",
   "scripts": {
     "all": "run-s lint test-coverage",
-    "lint": "eslint .",
+    "lint": "eslint . --ext js,mjs",
     "dev": "npm test -- --watch",
     "test": "mocha --exclude 'test/integration/*/**' 'test/**/*.*js'",
     "test-coverage": "nyc --reporter=lcov --reporter=html npm test",

diff --git a/rules/link-event.js b/rules/link-event.js
@@ -0,0 +1,100 @@
+const {
+  groupBy
+} = require('min-dash');
+
+const {
+  is
+} = require('bpmnlint-utils');
+
+
+/**
+ * A rule that verifies that link events are properly used.
+ *
+ * This implies:
+ *
+ *   * for every link throw there exists a link catch within
+ *     the same scope, and vice versa
+ *   * there exists only a single pair of [ throw, catch ] links
+ *     with a given name, per scope
+ *   * link events have a name
+ *
+ */
+module.exports = function() {
+
+  function check(node, reporter) {
+
+    if (!is(node, 'bpmn:FlowElementsContainer')) {
+      return;
+    }
+
+    const links = (node.flowElements || []).filter(isLinkEvent);
+
+    for (const link of links) {
+      if (!link.name) {
+        reporter.report(link.id, 'Link event is missing name');
+      }
+    }
+
+    const names = groupBy(links, (link) => link.name);
+
+    for (const [ name, events ] of Object.entries(names)) {
+
+      // ignore unnamed (validated earlier)
+      if (!name) {
+        continue;
+      }
+
+      // missing catch or throw event
+      if (events.length === 1) {
+        const event = events[0];
+
+        reporter.report(event.id, `Link ${isThrowEvent(event) ? 'catch' : 'throw' } event with name <${ name }> missing in scope`);
+      }
+
+      const throwEvents = events.filter(isThrowEvent);
+
+      if (throwEvents.length > 1) {
+        for (const event of throwEvents) {
+          reporter.report(event.id, `Duplicate link throw event with name <${name}> in scope`);
+        }
+      }
+
+      const catchEvents = events.filter(isCatchEvent);
+
+      if (catchEvents.length > 1) {
+        for (const event of catchEvents) {
+          reporter.report(event.id, `Duplicate link catch event with name <${name}> in scope`);
+        }
+      }
+    }
+
+  }
+
+  return {
+    check
+  };
+};
+
+
+// helpers /////////////////
+
+function isLinkEvent(node) {
+
+  var eventDefinitions = node.eventDefinitions || [];
+
+  if (!is(node, 'bpmn:Event')) {
+    return false;
+  }
+
+  return eventDefinitions.some(
+    definition => is(definition, 'bpmn:LinkEventDefinition')
+  );
+}
+
+function isThrowEvent(node) {
+  return is(node, 'bpmn:ThrowEvent');
+}
+
+function isCatchEvent(node) {
+  return is(node, 'bpmn:CatchEvent');
+}