From 6059e1362a7f91acdbc904c686ccf85f7e623044 Mon Sep 17 00:00:00 2001
From: zizou <111426680+flopell@users.noreply.github.com>
Date: Tue, 7 Jan 2025 10:03:49 +0100
Subject: [PATCH] refactor(example): early error if `RPC_URL` isn't set in
 `price_printer`

---
 examples/price_printer/main.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/examples/price_printer/main.rs b/examples/price_printer/main.rs
index b7684ae4..4c6a033f 100644
--- a/examples/price_printer/main.rs
+++ b/examples/price_printer/main.rs
@@ -43,6 +43,11 @@ async fn main() {
     let tycho_api_key: String =
         env::var("TYCHO_API_KEY").unwrap_or_else(|_| "sampletoken".to_string());
 
+    // Perform an early check to ensure `RPC_URL` is set.
+    // This prevents errors from occurring later during UI interactions.
+    // Can be commented out if only using the example with uniswap_v2 and uniswap_v3.
+    env::var("RPC_URL").expect("RPC_URL env variable should be set");
+
     // Create communication channels for inter-thread communication
     let (tick_tx, tick_rx) = mpsc::channel::<BlockUpdate>(12);