fix: Convert vendor/pezkuwi-subxt from submodule to regular directory

vendor/pezkuwi-subxt/testing/wasm-lightclient-tests/tests/wasm.rs

@@ -0,0 +1,76 @@
+#![cfg(target_arch = "wasm32")]
+
+use futures_util::StreamExt;
+use subxt::{client::OnlineClient, config::PolkadotConfig, lightclient::LightClient};
+use wasm_bindgen_test::*;
+
+wasm_bindgen_test::wasm_bindgen_test_configure!(run_in_browser);
+
+// Run the tests by calling:
+//
+// ```text
+// wasm-pack test --firefox --headless
+// ```
+//
+// Use the following to enable logs:
+// ```
+//  console_error_panic_hook::set_once();
+//  tracing_wasm::set_as_global_default();
+// ```
+
+#[wasm_bindgen_test]
+async fn light_client_works() {
+    let api = connect_to_rpc_node().await;
+
+    tracing::info!("Subscribe to latest finalized blocks: ");
+
+    let mut blocks_sub = api
+        .blocks()
+        .subscribe_finalized()
+        .await
+        .expect("Cannot subscribe to finalized hashes")
+        .take(3);
+
+    // For each block, print information about it:
+    while let Some(block) = blocks_sub.next().await {
+        let block = block.expect("Block not valid");
+
+        let block_number = block.header().number;
+        let block_hash = block.hash();
+
+        tracing::info!("Block #{block_number}:");
+        tracing::info!("  Hash: {block_hash}");
+    }
+}
+
+/// We connect to an RPC node because the light client can struggle to sync in
+/// time to a new local node for some reason. Because this can be brittle (eg RPC nodes can
+/// go down or have network issues), we try a few RPC nodes until we find one that works.
+async fn connect_to_rpc_node() -> OnlineClient<PolkadotConfig> {
+    let rpc_node_urls = [
+        "wss://rpc.polkadot.io",
+        "wss://1rpc.io/dot",
+        "wss://polkadot-public-rpc.blockops.network/ws",
+    ];
+
+    async fn do_connect(
+        url: &str,
+    ) -> Result<OnlineClient<PolkadotConfig>, Box<dyn std::error::Error + Send + Sync + 'static>>
+    {
+        let chainspec = subxt::utils::fetch_chainspec_from_rpc_node(url).await?;
+        let (_lc, rpc) = LightClient::relay_chain(chainspec.get())?;
+        let api = OnlineClient::from_rpc_client(rpc).await?;
+        Ok(api)
+    }
+
+    for url in rpc_node_urls {
+        let res = do_connect(url).await;
+
+        match res {
+            Ok(api) => return api,
+            Err(e) => tracing::warn!("Error connecting to RPC node {url}: {e}"),
+        }
+    }
+
+    panic!("Could not connect to any RPC node")
+}