Exclude the JoinSet::extend doc test for WASM

Add the doc test as IT test too

Author: martin-g

tokio/src/task/join_set.rs

@@ -656,6 +656,8 @@ where
 /// # Examples
 ///
 /// ```
+/// # #[cfg(not(target_family = "wasm"))]
+/// # {
 /// use tokio::task::JoinSet;
 ///
 /// #[tokio::main]
@@ -674,14 +676,18 @@ where
 ///         assert!(seen[i]);
 ///     }
 /// }
+/// # }
 /// ```
 impl<T, F> std::iter::Extend<F> for JoinSet<T>
 where
     F: Future<Output = T>,
     F: Send + 'static,
     T: Send + 'static,
 {
-    fn extend<I: IntoIterator<Item = F>>(&mut self, iter: I) {
+    fn extend<I>(&mut self, iter: I)
+    where
+        I: IntoIterator<Item = F>,
+    {
         iter.into_iter().for_each(|task| {
             self.spawn(task);
         });

tokio/tests/task_join_set.rs

@@ -404,6 +404,23 @@ async fn try_join_next_with_id() {
     assert_eq!(joined, spawned);
 }
 
+#[tokio::test]
+async fn extend() {
+    let mut set: JoinSet<_> = (0..5).map(|i| async move { i }).collect();
+
+    set.extend((5..10).map(|i| async move { i }));
+
+    let mut seen = [false; 10];
+    while let Some(res) = set.join_next().await {
+        let idx = res.unwrap();
+        seen[idx] = true;
+    }
+
+    for i in 0..10 {
+        assert!(seen[i]);
+    }
+}
+
 mod spawn_local {
     use super::*;