Fix cyclic check issues

src/nodesReducer.ts

@@ -342,36 +342,43 @@ const nodesReducer = (
   switch (action.type) {
     case NodesActionType.ADD_CONNECTION: {
       const { input, output } = action;
+
       const inputIsNotConnected = !nodes[input.nodeId].connections.inputs[
         input.portName
       ];
-      if (inputIsNotConnected) {
-        const allowCircular =
-          circularBehavior === "warn" || circularBehavior === "allow";
-        const newNodes = addConnection(nodes, input, output, portTypes);
-        const isCircular = checkForCircularNodes(newNodes, output.nodeId);
-        if (isCircular && !allowCircular) {
-          dispatchToasts?.({
-            type: ToastActionTypes.ADD_TOAST,
-            title: "Unable to connect",
-            message: "Connecting these nodes would result in an infinite loop.",
-            toastType: "warning",
-            duration: 5000
-          });
-          return nodes;
-        } else {
-          if (isCircular && circularBehavior === "warn") {
-            dispatchToasts?.({
-              type: ToastActionTypes.ADD_TOAST,
-              title: "Circular Connection Detected",
-              message: "Connecting these nodes has created an infinite loop.",
-              toastType: "warning",
-              duration: 5000
-            });
-          }
-          return newNodes;
-        }
-      } else return nodes;
+
+      if (!inputIsNotConnected)
+        return nodes;
+
+      const newNodes = addConnection(nodes, input, output, portTypes);
+
+      if (circularBehavior === "allow")
+        return newNodes;
+
+      const isCircular = checkForCircularNodes(newNodes, output.nodeId);
+      if (!isCircular)
+        return newNodes;
+
+      if (circularBehavior === "prevent") {
+        dispatchToasts?.({
+          type: ToastActionTypes.ADD_TOAST,
+          title: "Unable to connect",
+          message: "Connecting these nodes would result in an infinite loop.",
+          toastType: "warning",
+          duration: 5000
+        });
+        return nodes;
+      }
+
+      dispatchToasts?.({
+        type: ToastActionTypes.ADD_TOAST,
+        title: "Circular Connection Detected",
+        message: "Connecting these nodes has created an infinite loop.",
+        toastType: "warning",
+        duration: 5000
+      });
+
+      return newNodes;
     }
 
     case NodesActionType.REMOVE_CONNECTION: {

src/utilities.ts

@@ -4,25 +4,33 @@ export const checkForCircularNodes = (
   nodes: { [nodeId: string]: FlumeNode },
   startNodeId: string
 ) => {
-  let isCircular = false;
-  const walk = (nodeId: string) => {
-    const outputs = Object.values(nodes[nodeId].connections.outputs);
-    for (var i = 0; i < outputs.length; i++) {
-      if (isCircular) {
-        break;
-      }
-      const outputConnections = outputs[i];
-      for (var k = 0; k < outputConnections.length; k++) {
-        const connectedTo = outputConnections[k];
-        if (connectedTo.nodeId === startNodeId) {
-          isCircular = true;
-          break;
-        } else {
-          walk(connectedTo.nodeId);
-        }
-      }
+
+  let queue: string[] = [startNodeId]
+  let visitedNodes: FlumeNode[] = []
+
+  while (queue.length > 0) {
+    let currentNodeId = queue.pop();
+    if (currentNodeId == undefined)
+      return;
+
+    let currentNode = nodes[currentNodeId];
+
+    if (visitedNodes.includes(currentNode)) {
+      return true;
+    }
+
+    visitedNodes.push(currentNode);
+
+    if (currentNode.connections == undefined)
+      continue;
+    let outputs = currentNode.connections.outputs;
+
+    for (let output in outputs) {
+      let outputArray = outputs[output]
+      queue = queue.concat(outputArray.map(x => x.nodeId).filter((value, index, array) => array.indexOf(value) == index));
     }
-  };
-  walk(startNodeId);
-  return isCircular;
+  }
+
+  return false;
+
 };