wip: mimic Camunda Platform on inclusive gateway join

lib/simulator/behaviors/InclusiveGatewayBehavior.js

@@ -29,29 +29,25 @@ InclusiveGatewayBehavior.prototype.enter = function(context) {
     parent: parentScope
   } = scope;
 
-  const sameParentScopes = this._simulator.findScopes(scope => (
-    scope.parent === parentScope && scope.element !== element));
-
-  // There are still some tokens to wait for.
-  if (this._canReachAnyScope(sameParentScopes, element)) {
-    return;
-  }
-
   const elementScopes = this._simulator.findScopes({
     parent: parentScope,
     element: element
   });
 
-  for (const childScope of elementScopes) {
+  // Join if tokens waiting cover each incoming sequence flow.
+  if (elementScopes.length === incomingSequenceFlows.length) {
+    return this._join(context);
+  }
 
-    if (childScope !== scope) {
+  const sameParentScopes = this._simulator.findScopes(scope => (
+    scope.parent === parentScope && scope.element !== element));
 
-      // complete joining child scope
-      this._simulator.destroyScope(childScope.complete(), scope);
-    }
+  // There are still some tokens to wait for.
+  if (this._canReachAnyScope(sameParentScopes, element)) {
+    return;
   }
 
-  this._simulator.exit(context);
+  this._join(context);
 };
 
 InclusiveGatewayBehavior.prototype.exit = function(context) {
@@ -89,6 +85,24 @@ InclusiveGatewayBehavior.prototype.exit = function(context) {
   }
 };
 
+InclusiveGatewayBehavior.prototype._join = function(context) {
+  const elementScopes = this._simulator.findScopes({
+    parent: context.parent,
+    element: context.element
+  });
+
+  for (const childScope of elementScopes) {
+
+    if (childScope !== context.scope) {
+
+      // complete joining child scope
+      this._simulator.destroyScope(childScope.complete(), context.scope);
+    }
+  }
+
+  this._simulator.exit(context);
+};
+
 InclusiveGatewayBehavior.prototype._canReachAnyScope = function(scopes, currentElement, traversed = new Set()) {
   if (traversed.has(currentElement)) {
     return false;