feat: add yield_now

Needed if loop doesn't yield in and only one thread it available (wasm)

Cargo.toml

@@ -23,6 +23,8 @@ tokio = { version = "1", default-features = false, optional = true }
 # For compiling to wasm:
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 wasm-bindgen-futures = "0.4.34"
+js-sys = { version = "0.3.69", optional = true }
+web-sys = { version = "0.3.69", optional = true }
 
 [dev-dependencies]
 futures = "0.3.28"
@@ -32,16 +34,12 @@ wasm-bindgen-test = "0.3.34"
 [target.'cfg(not(target_arch = "wasm32"))'.dev-dependencies]
 tokio = { version = "1.27.0", default-features = false, features = ["macros", "rt-multi-thread"] }
 
-[target.'cfg(target_arch = "wasm32")'.dev-dependencies]
-js-sys = "0.3.69"
-web-sys = "0.3.69"
-# Uncomment below to include example in tests (already covered by doc-test plus dedicated test)
-# [[example]]
-# name = "simple_fetch"
-# harness = false
-# test = true
+[[example]]
+name = "loop_yield"
+required-features = ["yield_now"]
 
 [features]
 default = ["native-tokio"]
 native-tokio = ["dep:tokio"]
+yield_now = ["dep:js-sys", "web-sys"]
 # If we add support for other runtimes we need to update CI to test each separately (rn tests all features together)

examples/loop_yield.rs

@@ -61,7 +61,7 @@ async fn common_code() -> Result<(), Box<dyn std::error::Error>> {
                         } else {
                             // Still waiting
                             state = State::AwaitingResponse(rx);
-                            yield_().await;
+                            reqwest_cross::yield_now().await;
                         }
                     }
                     Err(e) => {
@@ -80,33 +80,11 @@ async fn common_code() -> Result<(), Box<dyn std::error::Error>> {
 }
 
 #[cfg(all(test, not(target_arch = "wasm32")))]
+
 mod tests {
-    use super::*;
 
     #[tokio::test]
     async fn test_name() {
-        common_code().await.unwrap();
+        super::common_code().await.unwrap();
     }
 }
-
-/// Yield to other tasks
-async fn yield_() {
-    #[cfg(target_arch = "wasm32")]
-    sleep_ms(1).await;
-    #[cfg(not(target_arch = "wasm32"))]
-    tokio::task::yield_now().await;
-}
-
-#[cfg(target_arch = "wasm32")]
-// Hack to get async sleep on wasm
-// Taken from https://github.com/rustwasm/wasm-bindgen/discussions/3476
-async fn sleep_ms(millis: i32) {
-    let mut cb = |resolve: js_sys::Function, _reject: js_sys::Function| {
-        web_sys::window()
-            .unwrap()
-            .set_timeout_with_callback_and_timeout_and_arguments_0(&resolve, millis)
-            .expect("Failed to call set_timeout");
-    };
-    let p = js_sys::Promise::new(&mut cb);
-    wasm_bindgen_futures::JsFuture::from(p).await.unwrap();
-}

src/lib.rs

@@ -67,10 +67,12 @@ mod native;
 #[cfg(target_arch = "wasm32")]
 mod wasm;
 mod wrappers;
+#[cfg(feature = "yield_now")]
+mod yield_;
 
 pub use wrappers::fetch;
+#[cfg(feature = "yield_now")]
+pub use yield_::yield_now;
 
 // TODO 3: Reexport the client so including reqwest directly is not necessary
-
-// TODO 2: Create examples in the examples folder and reference them from the
-//          docs instead of point ppl at the tests
+// TODO 3: Check output of docs

src/yield_.rs

@@ -0,0 +1,24 @@
+/// Attempts to provide a yield for executor currently in use.
+/// There doesn't appear to be one available as yet for wasm_bindgen_futures so
+/// a workaround taken from
+/// https://github.com/rustwasm/wasm-bindgen/discussions/3476 is used
+pub async fn yield_now() {
+    #[cfg(target_arch = "wasm32")]
+    sleep_ms(1).await;
+    #[cfg(not(target_arch = "wasm32"))]
+    tokio::task::yield_now().await;
+}
+
+#[cfg(target_arch = "wasm32")]
+// Hack to get async sleep on wasm
+// Taken from https://github.com/rustwasm/wasm-bindgen/discussions/3476
+async fn sleep_ms(millis: i32) {
+    let mut cb = |resolve: js_sys::Function, _reject: js_sys::Function| {
+        web_sys::window()
+            .unwrap()
+            .set_timeout_with_callback_and_timeout_and_arguments_0(&resolve, millis)
+            .expect("Failed to call set_timeout");
+    };
+    let p = js_sys::Promise::new(&mut cb);
+    wasm_bindgen_futures::JsFuture::from(p).await.unwrap();
+}