From 72f6ad8d9987d29deb987d6a0fdd0b9ee814c720 Mon Sep 17 00:00:00 2001
From: Hetu Nandu <hetunandu@gmail.com>
Date: Fri, 1 Oct 2021 20:39:09 +0530
Subject: [PATCH] fix: Cyclic dependency not resolving in JS Editor (#8003)

---
 app/client/src/workers/evaluation.worker.ts | 26 ++++++++++++++-------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/app/client/src/workers/evaluation.worker.ts b/app/client/src/workers/evaluation.worker.ts
index 8708df5073..b2ae9eae9a 100644
--- a/app/client/src/workers/evaluation.worker.ts
+++ b/app/client/src/workers/evaluation.worker.ts
@@ -235,22 +235,28 @@ ctx.addEventListener(
       }
       case EVAL_WORKER_ACTIONS.PARSE_JS_FUNCTION_BODY: {
         const { body, jsAction } = requestData;
-
-        if (!dataTreeEvaluator) {
-          return true;
-        }
+        /**
+         * In case of a cyclical dependency, the dataTreeEvaluator will not
+         * be present. This causes an issue because evalTree is needed to resolve
+         * the cyclical dependency in a JS Collection
+         *
+         * By setting evalTree to an empty object, the parsing can still take place
+         * and it would resolve the cyclical dependency
+         * **/
+        const currentEvalTree = dataTreeEvaluator
+          ? dataTreeEvaluator.evalTree
+          : {};
         try {
           const { evalTree, result } = parseJSCollection(
             body,
             jsAction,
-            dataTreeEvaluator.evalTree,
+            currentEvalTree,
           );
           return {
             evalTree,
             result,
           };
         } catch (e) {
-          const evalTree = dataTreeEvaluator.evalTree;
           const errors = [
             {
               errorType: PropertyEvaluationErrorType.PARSE,
@@ -259,9 +265,13 @@ ctx.addEventListener(
               errorMessage: e.message,
             },
           ];
-          _.set(evalTree, `${jsAction.name}.${EVAL_ERROR_PATH}.body`, errors);
+          _.set(
+            currentEvalTree,
+            `${jsAction.name}.${EVAL_ERROR_PATH}.body`,
+            errors,
+          );
           return {
-            evalTree,
+            currentEvalTree,
           };
         }
       }