Fix synchronous suspense cases on client-side

package.json

@@ -136,8 +136,8 @@
     "react": ">= 16.8.0"
   },
   "dependencies": {
-    "react-wonka": "^2.0.0",
+    "react-wonka": "^2.0.1",
     "scheduler": ">= 0.16.0",
-    "wonka": "^4.0.5"
+    "wonka": "^4.0.7"
   }
 }

src/utils/toSuspenseSource.test.ts

@@ -72,7 +72,9 @@ it('throws a promise that resolves when the source emits a value', () => {
   expect(promise).toBeInstanceOf(Promise);
 
   next('test');
-  expect(result).toBe('test');
+
+  // The result came in asynchronously and the original source has ended
+  expect(result).toBe(undefined);
 
   return promise.then(resolved => {
     expect(resolved).toBe('test');

src/utils/toSuspenseSource.ts

@@ -1,48 +1,20 @@
-import { pipe, make, onPush, onEnd, subscribe, Source } from 'wonka';
+import { pipe, share, onPush, toPromise, takeWhile, take, Source } from 'wonka';
 
 /** This converts a Source to a suspense Source; It will forward the first result synchronously or throw a promise that resolves when the result becomes available */
-export const toSuspenseSource = <T>(source: Source<T>): Source<T> => {
-  // Create a new Source from scratch so we have full control over the Source's lifecycle
-  return make<T>(({ next, complete }) => {
-    let isCancelled = false;
-    let resolveSuspense: (value: T) => void;
-    let synchronousResult: undefined | T;
+export const toSuspenseSource = <T>(source: Source<T>): Source<T> => sink => {
+  const shared = share(source);
+  let hasResult = false;
+  let hasSuspended = false;
 
-    const { unsubscribe } = pipe(
-      source,
-      // The onPush and onEnd forward the underlying results as usual, so that when no
-      // suspense promise is thrown, the source behaves as it normally would
-      onPush(next),
-      onEnd(complete as any),
-      subscribe(value => {
-        // When this operation resolved synchronously assign the result to
-        // synchronousResult which will be picked up below
-        if (resolveSuspense === undefined) {
-          synchronousResult = value;
-        } else if (!isCancelled) {
-          // Otherwise resolve the thrown promise,
-          resolveSuspense(value);
-          // And end and teardown both sources, since suspense will abort the
-          // underlying rendering component anyway
-          complete();
-          unsubscribe();
-        }
-      })
-    );
+  pipe(
+    shared,
+    takeWhile(() => !hasSuspended),
+    onPush(() => (hasResult = true))
+  )(sink);
 
-    // If we have a synchronous result, push it onto this source, which is synchronous
-    // otherwise throw a new promise which will resolve later
-    if (synchronousResult === undefined) {
-      throw new Promise(resolve => {
-        resolveSuspense = resolve;
-      });
-    }
-
-    // Since promises aren't cancellable we have a flag that prevents
-    // the thrown promise from resolving if this source is cancelled
-    return () => {
-      isCancelled = true;
-      unsubscribe();
-    };
-  });
+  if (!hasResult) {
+    hasSuspended = true;
+    sink(0); /* End */
+    throw pipe(shared, take(1), toPromise);
+  }
 };

yarn.lock

@@ -4718,10 +4718,10 @@ react-test-renderer@^16.0.0-0, react-test-renderer@^16.12.0:
     react-is "^16.8.6"
     scheduler "^0.18.0"
 
-react-wonka@^2.0.0:
-  version "2.0.0"
-  resolved "https://registry.yarnpkg.com/react-wonka/-/react-wonka-2.0.0.tgz#d62d87c9c93ec3e603ecf1582df3615aadc5c2e9"
-  integrity sha512-7q0CNBnSltRyzb61joCxKqVntHbRJRhP/WPxEx+zM8l9Yd+0IRevJuPG8iCamgrGphusX5xtEtd4yyX7qvRM1g==
+react-wonka@^2.0.1:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/react-wonka/-/react-wonka-2.0.1.tgz#75bdf03dbad8ceb8c1066216f635f05ce2b642a5"
+  integrity sha512-mM2UH2gnK5LLzaqVWd6JCLrB1vO3I4PN/sQZbjvzsjms4vSv+nKwelNUftM0KeC+LtTPC4GGsuxyu2XJnsCUTw==
 
 react@^16.12.0:
   version "16.12.0"
@@ -5981,10 +5981,10 @@ wide-align@^1.1.0:
   dependencies:
     string-width "^1.0.2 || 2"
 
-wonka@^4.0.5:
-  version "4.0.5"
-  resolved "https://registry.yarnpkg.com/wonka/-/wonka-4.0.5.tgz#3384b90ed8c1e6e182d6e2fb18468c33ab94e0af"
-  integrity sha512-XKnzSpsk2UcPfyjecdc14b7LZSPeOEhYEs+/oAZ+gXV9BuYIcZC3hpapFi2DFHj1Bk38/npusgkiSD0+KdyCzQ==
+wonka@^4.0.7:
+  version "4.0.7"
+  resolved "https://registry.yarnpkg.com/wonka/-/wonka-4.0.7.tgz#b4934685bd2449367bd72ce7770bfe3e6cc8a68b"
+  integrity sha512-Uhyl2cgWCUksYtU0Jt8MSzKUqK4BVUrewWxnn1YlKL3Zco4sDcCUDkbgH0i762HJs1rtsq03cfzsCWxJKaDgVg==
 
 word-wrap@~1.2.3:
   version "1.2.3"