fix: Fix Promise::awaitFuture actually locking threads (#347)

* fix: Fix `Promise::awaitFuture` actually locking threads

* fix: Make tests only wait 1s instead of 2s

example/src/getTests.ts

@@ -664,10 +664,10 @@ export function getTests(
       (
         await it(async () => {
           const start = performance.now()
-          // 2s + 2s = ~4s in serial, ~2s in parallel
-          await Promise.all([testObject.wait(2), testObject.wait(2)])
+          // 0.5s + 0.5s = ~1s in serial, ~0.5s in parallel
+          await Promise.all([testObject.wait(0.5), testObject.wait(0.5)])
           const end = performance.now()
-          const didRunInParallel = end - start < 4000
+          const didRunInParallel = end - start < 1000
           return didRunInParallel
         })
       )

packages/react-native-nitro-modules/cpp/core/Promise.hpp

@@ -62,11 +62,8 @@ class Promise final {
    * Once the future resolves or rejects, the Promise resolves or rejects.
    */
   static std::shared_ptr<Promise> awaitFuture(std::future<TResult>&& future) {
-    std::shared_future<TResult> sharedFuture(std::move(future));
-    return async([sharedFuture = std::move(sharedFuture)]() {
-      sharedFuture.wait();
-      return sharedFuture.get();
-    });
+    auto sharedFuture = std::make_shared<std::future<TResult>>(std::move(future));
+    return async([sharedFuture = std::move(sharedFuture)]() { return sharedFuture->get(); });
   }
 
   /**
@@ -230,11 +227,8 @@ class Promise<void, TError> final {
   }
 
   static std::shared_ptr<Promise> awaitFuture(std::future<void>&& future) {
-    std::shared_future<void> sharedFuture(std::move(future));
-    return async([sharedFuture = std::move(sharedFuture)]() {
-      sharedFuture.wait();
-      sharedFuture.get();
-    });
+    auto sharedFuture = std::make_shared<std::future<void>>(std::move(future));
+    return async([sharedFuture = std::move(sharedFuture)]() { sharedFuture->get(); });
   }
 
   static std::shared_ptr<Promise> resolved() {