From dcdad9204059f84e61fd589fa24e3a0710e12731 Mon Sep 17 00:00:00 2001
From: Tomek Zawadzki <tomasz.zawadzki@swmansion.com>
Date: Thu, 5 Jan 2023 12:21:09 +0100
Subject: [PATCH] Add user-friendly error message when worklet cannot be
 created due to missing Babel plugin (#3893)

## Summary

This PR adds an user-friendly error message when worklet cannot be created due to missing Reanimated Babel plugin.

Before:
![before](https://user-images.githubusercontent.com/20516055/210056688-18ef9023-cd9b-4f05-8384-61c2056fed00.png)

After:
![after](https://user-images.githubusercontent.com/20516055/210056691-23b01891-7b27-493f-af1d-aa4df664d6bf.png)

## Test plan

Check on a fresh RN app without editing `babel.config.js`.
---
 src/reanimated2/threads.ts | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/reanimated2/threads.ts b/src/reanimated2/threads.ts
index 006f47ba307..02b497ca445 100644
--- a/src/reanimated2/threads.ts
+++ b/src/reanimated2/threads.ts
@@ -23,6 +23,18 @@ export function runOnUI<A extends any[], R>(
   };
 }
 
+if (__DEV__) {
+  try {
+    runOnUI(() => {
+      'worklet';
+    });
+  } catch (e) {
+    throw new Error(
+      'Failed to create a worklet. Did you forget to add Reanimated Babel plugin in babel.config.js? See installation docs at https://docs.swmansion.com/react-native-reanimated/docs/fundamentals/installation#babel-plugin.'
+    );
+  }
+}
+
 export function runOnJS<A extends any[], R>(
   fun: ComplexWorkletFunction<A, R>
 ): (...args: A) => void {