Add stream feature to futures crate

crates/futures/Cargo.toml

@@ -14,7 +14,10 @@ edition = "2018"
 cfg-if = "1.0.0"
 js-sys = { path = "../js-sys", version = '0.3.46' }
 wasm-bindgen = { path = "../..", version = '0.2.69' }
-futures-core =  { version = '0.3.8', default-features = false }
+futures-core =  { version = '0.3.8', default-features = false, optional = true }
+
+[features]
+futures-core-03-stream = ['futures-core']
 
 [target.'cfg(target_feature = "atomics")'.dependencies.web-sys]
 path = "../web-sys"

crates/futures/README.md

@@ -8,6 +8,9 @@ This crate bridges the gap between a Rust `Future` and a JavaScript
 1. From a JavaScript `Promise` into a Rust `Future`.
 2. From a Rust `Future` into a JavaScript `Promise`.
 
+Additionally under the feature flag `futures-core-03-stream` there is experimental 
+support for `AsyncIterator` to `Stream` conversion.
+
 See the [API documentation][docs] for more info.
 
 [docs]: https://rustwasm.github.io/wasm-bindgen/api/wasm_bindgen_futures/

crates/futures/src/lib.rs

@@ -43,6 +43,7 @@ use std::task::{Context, Poll, Waker};
 use wasm_bindgen::prelude::*;
 
 mod queue;
+#[cfg(feature = "futures-core-03-stream")]
 pub mod stream;
 
 mod task {

crates/futures/tests/tests.rs

@@ -3,8 +3,8 @@
 wasm_bindgen_test::wasm_bindgen_test_configure!(run_in_browser);
 
 use futures_channel::oneshot;
-use wasm_bindgen::{prelude::*, JsCast};
-use wasm_bindgen_futures::{future_to_promise, spawn_local, stream::JsStream, JsFuture};
+use wasm_bindgen::prelude::*;
+use wasm_bindgen_futures::{future_to_promise, spawn_local, JsFuture};
 use wasm_bindgen_test::*;
 
 #[wasm_bindgen_test]
@@ -89,9 +89,13 @@ async fn can_create_multiple_futures_from_same_promise() {
     b.await.unwrap();
 }
 
+#[cfg(feature = "futures-core-03-stream")]
 #[wasm_bindgen_test]
 async fn can_use_an_async_iterable_as_stream() {
     use futures_lite::stream::StreamExt;
+    use wasm_bindgen::JsCast;
+    use wasm_bindgen_futures::stream::JsStream;
+
     let async_iter = js_sys::Function::new_no_args(
         "return async function*() { 
             yield 42;