add wasm support (#700)

* get started

* make it work again

* make it compile again

* Use async-wasm-feature of jsonrpsee from the master branch

* Ensure we enable JS feature of getrandom for the wasm target

* Update subxt/src/lib.rs

* update jsonrpsee

* fix CI

* cargo fmt

* fix wasm test

* fix grumbles

* exclude wasm-tests from workspace

To avoid leaking `jsonrpsee-web` feature into the workspace

Co-authored-by: Igor Matuszewski <xanewok@gmail.com>

testing/test-runtime/Cargo.toml

@@ -13,4 +13,4 @@ subxt = { path = "../../subxt" }
 sp-core = "6.0.0"
 tokio = { version = "1.8", features = ["macros", "rt-multi-thread"] }
 which = "4.2.2"
-jsonrpsee = { version = "0.15.1", features = ["async-client", "client-ws-transport"] }
+jsonrpsee = { version = "0.16.0", features = ["async-client", "client-ws-transport"] }

testing/test-runtime/build.rs

@@ -60,7 +60,7 @@ async fn run() {
             // Thus, the connection might get rejected a few times.
             use client::ClientT;
             let res = match client::build(&format!("ws://localhost:{}", port)).await {
-                Ok(c) => c.request("state_getMetadata", None).await,
+                Ok(c) => c.request("state_getMetadata", client::rpc_params![]).await,
                 Err(e) => Err(e),
             };
 
@@ -174,7 +174,10 @@ mod client {
         },
     };
 
-    pub use jsonrpsee::core::client::ClientT;
+    pub use jsonrpsee::core::{
+        client::ClientT,
+        rpc_params,
+    };
 
     /// Build WS RPC client from URL
     pub async fn build(url: &str) -> Result<Client, Error> {

testing/wasm-tests/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "wasm-test"
+version = "0.1.0"
+edition = "2021"
+
+[dev-dependencies]
+wasm-bindgen-test = "0.3.24"
+tracing-wasm = "0.2.1"
+console_error_panic_hook = "0.1.7"
+serde_json = "1.0.57"
+subxt = { path = "../../subxt", default-features = false, features = ["jsonrpsee-web"] }

testing/wasm-tests/tests/wasm.rs

@@ -0,0 +1,26 @@
+#![cfg(target_arch = "wasm32")]
+
+use subxt::config::PolkadotConfig;
+use wasm_bindgen_test::*;
+
+wasm_bindgen_test::wasm_bindgen_test_configure!(run_in_browser);
+
+/// Run the tests by `$ wasm-pack test --firefox --headless`
+
+fn init_tracing() {
+    console_error_panic_hook::set_once();
+    tracing_wasm::set_as_global_default();
+}
+
+#[wasm_bindgen_test]
+async fn wasm_ws_transport_works() {
+    init_tracing();
+
+    let client =
+        subxt::client::OnlineClient::<PolkadotConfig>::from_url("ws://127.0.0.1:9944")
+            .await
+            .unwrap();
+
+    let chain = client.rpc().system_chain().await.unwrap();
+    assert_eq!(&chain, "Development");
+}