Add gRPC-web support in WASM #701 (BCHD API for SLP). (#1127)

* WIP. Adding RequestBody::Bytes.

* WIP. gRPC-web doesn't work under WASM yet.

* WIP. Catching up with dev. WASM doesn't compile.

* Fixed compilation after merging with dev. Some tests fail.

* WIP. Added x-grpc-web header to make CORS working. Tests still fail for other reason.

* Got gRPC-web working in WASM. Added Provider::Nomics.

mm2src/coins/utxo/bchd_grpc.rs

@@ -416,3 +416,19 @@ mod bchd_grpc_tests {
         }
     }
 }
+
+#[cfg(target_arch = "wasm32")]
+mod wasm_tests {
+    use super::*;
+    use wasm_bindgen_test::*;
+
+    wasm_bindgen_test_configure!(run_in_browser);
+
+    #[wasm_bindgen_test]
+    async fn test_check_slp_transaction_valid() {
+        let url = "https://bchd-testnet.greyh.at:18335";
+        // https://testnet.simpleledger.info/tx/c5f46ccc5431687154335d5b6526f1b9cfa961c44b97956b7bec77f884f56c73
+        let tx = hex::decode("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").unwrap();
+        check_slp_transaction(&[url], tx).await.unwrap();
+    }
+}

mm2src/common/grpc_web.rs

@@ -147,11 +147,22 @@ where
 }
 
 #[cfg(target_arch = "wasm32")]
-pub async fn post_grpc_web<Req, Res>(url: &str, _req: &Req) -> Result<Res, MmError<PostGrpcWebErr>>
+pub async fn post_grpc_web<Req, Res>(url: &str, req: &Req) -> Result<Res, MmError<PostGrpcWebErr>>
 where
     Req: prost::Message + Send + 'static,
     Res: prost::Message + Default + Send + 'static,
 {
-    let _request = FetchRequest::post(url);
-    unimplemented!()
+    let body = encode_body(req)?;
+    let request = FetchRequest::post(url)
+        .body_bytes(body)
+        .header("content-type", "application/grpc-web+proto")
+        .header("accept", "application/grpc-web+proto")
+        // https://github.com/grpc/grpc-web/issues/85#issue-217223001
+        .header("x-grpc-web", "1");
+
+    let response = request.request_array().await?;
+
+    let reply = decode_body(response.1.into())?;
+
+    Ok(reply)
 }

mm2src/common/transport/wasm_http.rs

@@ -4,6 +4,7 @@ use crate::stringify_js_error;
 use crate::transport::{SlurpError, SlurpResult};
 use futures::channel::oneshot;
 use http::{HeaderMap, StatusCode};
+use js_sys::Uint8Array;
 use std::collections::HashMap;
 use wasm_bindgen::prelude::*;
 use wasm_bindgen::JsCast;
@@ -67,6 +68,11 @@ impl FetchRequest {
         self
     }
 
+    pub fn body_bytes(mut self, body: Vec<u8>) -> FetchRequest {
+        self.body = Some(RequestBody::Bytes(body));
+        self
+    }
+
     /// Set the mode to [`RequestMode::Cors`].
     /// The request is no-cors by default.
     pub fn cors(mut self) -> FetchRequest {
@@ -88,6 +94,15 @@ impl FetchRequest {
         }
     }
 
+    pub async fn request_array(self) -> FetchResult<Vec<u8>> {
+        let (tx, rx) = oneshot::channel();
+        Self::spawn_fetch_array(self, tx);
+        match rx.await {
+            Ok(res) => res,
+            Err(_e) => MmError::err(SlurpError::Internal("Spawned future has been canceled".to_owned())),
+        }
+    }
+
     fn spawn_fetch_str(request: Self, tx: oneshot::Sender<FetchResult<String>>) {
         let fut = async move {
             let result = Self::fetch_str(request).await;
@@ -96,8 +111,15 @@ impl FetchRequest {
         spawn_local(fut);
     }
 
-    /// The private non-Send method that is called in a spawned future.
-    async fn fetch_str(request: Self) -> FetchResult<String> {
+    fn spawn_fetch_array(request: Self, tx: oneshot::Sender<FetchResult<Vec<u8>>>) {
+        let fut = async move {
+            let result = Self::fetch_array(request).await;
+            tx.send(result).ok();
+        };
+        spawn_local(fut);
+    }
+
+    async fn fetch(request: Self) -> FetchResult<JsResponse> {
         let window = web_sys::window().expect("!window");
         let uri = request.uri;
 
@@ -133,6 +155,23 @@ impl FetchRequest {
             },
         };
 
+        let status_code = js_response.status();
+        let status_code = match StatusCode::from_u16(status_code) {
+            Ok(code) => code,
+            Err(e) => {
+                let error = format!("Unexpected HTTP status code, found {}: {}", status_code, e);
+                return MmError::err(SlurpError::ErrorDeserializing { uri, error });
+            },
+        };
+
+        Ok((status_code, js_response))
+    }
+
+    /// The private non-Send method that is called in a spawned future.
+    async fn fetch_str(request: Self) -> FetchResult<String> {
+        let uri = request.uri.clone();
+        let (status_code, js_response) = Self::fetch(request).await?;
+
         let resp_txt_fut = match js_response.text() {
             Ok(txt) => txt,
             Err(e) => {
@@ -155,15 +194,35 @@ impl FetchRequest {
             },
         };
 
-        let status_code = js_response.status();
-        let status_code = match StatusCode::from_u16(status_code) {
-            Ok(code) => code,
+        Ok((status_code, resp_str))
+    }
+
+    /// The private non-Send method that is called in a spawned future.
+    async fn fetch_array(request: Self) -> FetchResult<Vec<u8>> {
+        let uri = request.uri.clone();
+        let (status_code, js_response) = Self::fetch(request).await?;
+
+        let resp_array_fut = match js_response.array_buffer() {
+            Ok(blob) => blob,
             Err(e) => {
-                let error = format!("Unexpected HTTP status code, found {}: {}", status_code, e);
+                let error = format!(
+                    "Expected blob, found {:?}: {}",
+                    js_response,
+                    crate::stringify_js_error(&e)
+                );
                 return MmError::err(SlurpError::ErrorDeserializing { uri, error });
             },
         };
-        Ok((status_code, resp_str))
+        let resp_array = JsFuture::from(resp_array_fut)
+            .await
+            .map_to_mm(|e| SlurpError::ErrorDeserializing {
+                uri: uri.clone(),
+                error: stringify_js_error(&e),
+            })?;
+
+        let array = Uint8Array::new(&resp_array);
+
+        Ok((status_code, array.to_vec()))
     }
 }
 
@@ -183,12 +242,17 @@ impl FetchMethod {
 
 enum RequestBody {
     Utf8(String),
+    Bytes(Vec<u8>),
 }
 
 impl RequestBody {
     fn into_js_value(self) -> JsValue {
         match self {
             RequestBody::Utf8(string) => JsValue::from_str(&string),
+            RequestBody::Bytes(bytes) => {
+                let js_array = Uint8Array::from(bytes.as_slice());
+                js_array.into()
+            },
         }
     }
 }

mm2src/lp_ordermatch/lp_bot.rs

@@ -83,6 +83,8 @@ pub enum Provider {
     Coingecko,
     #[serde(rename = "coinpaprika")]
     Coinpaprika,
+    #[serde(rename = "nomics")]
+    Nomics,
     #[serde(rename = "unknown")]
     Unknown,
 }

mm2src/mm2_tests/lp_bot_tests.rs

@@ -11,10 +11,7 @@ mod tests {
 
     #[test]
     #[cfg(not(target_arch = "wasm32"))]
-    fn test_process_price_request() {
-        let resp = block_on(process_price_request(KMD_PRICE_ENDPOINT));
-        assert_ne!(resp.is_err(), true);
-    }
+    fn test_process_price_request() { let _resp = block_on(process_price_request(KMD_PRICE_ENDPOINT)).unwrap(); }
 
     #[test]
     #[cfg(not(target_arch = "wasm32"))]