testing: Retry on Tx::Dropped for lightclinet only

Signed-off-by: Alexandru Vasile <alexandru.vasile@parity.io>

testing/integration-tests/src/utils/tx_retries.rs

@@ -0,0 +1,40 @@
+// Copyright 2019-2024 Parity Technologies (UK) Ltd.
+// This file is dual-licensed as Apache-2.0 or GPL-3.0.
+// see LICENSE for license details.
+
+use subxt::client::OnlineClientT;
+use subxt::tx::SubmittableExtrinsic;
+use subxt::Config;
+
+pub async fn submit_tx_wait_for_finalized_success<T, C>(
+    signed_extrinsic: &SubmittableExtrinsic<T, C>,
+) -> Result<subxt::blocks::ExtrinsicEvents<T>, subxt::Error>
+where
+    T: Config,
+    C: OnlineClientT<T>,
+{
+    let submit = || async {
+        signed_extrinsic
+            .submit_and_watch()
+            .await
+            .unwrap()
+            .wait_for_finalized_success()
+            .await
+    };
+
+    #[cfg(lightclient)]
+    for _ in 0..2 {
+        let result = submit().await;
+
+        match result {
+            Ok(tx_in_block) => return Ok(tx_in_block),
+            Err(subxt::Error::Transaction(subxt::error::TransactionError::Dropped(_))) => {
+                // Retry if the transaction was dropped.
+                tokio::time::sleep(std::time::Duration::from_secs(5)).await;
+            }
+            Err(other) => return Err(other),
+        }
+    }
+
+    submit().await
+}