feat(notifier): allow makeSubscriptionKit(initialState)

Agoric · Jun 4, 2022 · f9894f6 · f9894f6
1 parent 59646f8
commit f9894f6
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Showing 2 changed files with 26 additions and 21 deletions.
diff --git a/packages/notifier/src/subscriber.js b/packages/notifier/src/subscriber.js
@@ -57,9 +57,10 @@ const makeSubscriptionIterator = tailP => {
  * distributed pub/sub.
  *
  * @template T
+ * @param {T[]} optionalInitialState
  * @returns {SubscriptionRecord<T>}
  */
-const makeSubscriptionKit = () => {
+const makeSubscriptionKit = (...optionalInitialState) => {
   /** @type {((internals: ERef<SubscriptionInternals<T>>) => void) | undefined} */
   let rear;
   const hp = new HandledPromise(r => (rear = r));
@@ -96,6 +97,10 @@ const makeSubscriptionKit = () => {
       rear = undefined;
     },
   });
+
+  if (optionalInitialState.length > 0) {
+    publication.updateState(optionalInitialState[0]);
+  }
   return harden({ publication, subscription });
 };
 harden(makeSubscriptionKit);

diff --git a/packages/notifier/test/test-stored-subscription.js b/packages/notifier/test/test-stored-subscription.js
@@ -29,11 +29,14 @@ const makeFakeStorage = (path, publication) => {
 };
 
 test('stored subscription', async t => {
-  t.plan((jsonPairs.length + 1) * 4 + 1);
+  t.plan((jsonPairs.length + 2) * 4 + 1);
+
+  /** @type {any} */
+  const initialValue = 'first value';
   const { publication: pubStorage, subscription: subStorage } =
     makeSubscriptionKit();
   const storage = makeFakeStorage('publish.foo.bar', pubStorage);
-  const { subscription, publication } = makeSubscriptionKit();
+  const { subscription, publication } = makeSubscriptionKit(initialValue);
   const storesub = makeStoredSubscription(subscription, storage);
 
   t.is(await E(storesub).getStoreKey(), await E(storage).getStoreKey());
@@ -43,22 +46,7 @@ test('stored subscription', async t => {
   const storeAit = subStorage[Symbol.asyncIterator]();
 
   const { unserialize } = makeMarshal();
-  const updateAndCheck = async (description, origValue, expectDone) => {
-    const nextP = E(ait).next();
-    if (expectDone) {
-      await E(publication).finish(origValue);
-    } else {
-      await E(publication).updateState(origValue);
-    }
-
-    const { done, value } = await nextP;
-    t.is(done, expectDone, `check doneness for ${description}`);
-    t.deepEqual(
-      value,
-      origValue,
-      `check value against original ${description}`,
-    );
-
+  const check = async (description, origValue, expectedDone) => {
     const { done: storedDone, value: storedEncoded } = await storeAit.next();
     t.assert(!storedDone, `check not stored done for ${description}`);
     const storedDecoded = JSON.parse(storedEncoded);
@@ -68,12 +56,24 @@ test('stored subscription', async t => {
       origValue,
       `check stored value against original ${description}`,
     );
+
+    const { done, value } = await E(ait).next();
+    t.is(done, expectedDone, `check doneness for ${description}`);
+    t.deepEqual(
+      value,
+      origValue,
+      `check value against original ${description}`,
+    );
   };
 
+  await check(initialValue, initialValue, false);
   for await (const [encoded] of jsonPairs) {
     const origValue = unserialize({ body: encoded, slots: [] });
-    await updateAndCheck(encoded, origValue, false);
+    await E(publication).updateState(origValue);
+    await check(encoded, origValue, false);
   }
 
-  await updateAndCheck('terminal', null, true);
+  const terminalNull = null;
+  await E(publication).finish(terminalNull);
+  await check('terminal null', terminalNull, true);
 });