resolve #465 update query on mutation success shorthand

packages/core/src/update/__tests__/update.test.ts

@@ -117,6 +117,35 @@ describe('update', () => {
     expect(listeners.onStart).toBeCalledTimes(1); // only original call
   });
 
+  test('refetch true causes query to be refetched with latest params shorthand', async () => {
+    const query = createQuery({
+      handler: vi.fn().mockImplementation((params: number) => setTimeout(100).then(() => params.toString())),
+      initialData: 'initial',
+    });
+
+    const mutation = createMutation({ handler: vi.fn().mockResolvedValue('from mutation') });
+
+    update(query, { on: mutation });
+
+    const scope = fork();
+    const { listeners } = watchRemoteOperation(query, scope);
+
+    await allSettled(query.start, { scope, params: 1 });
+    await allSettled(query.start, { scope, params: 2 });
+
+    allSettled(mutation.start, { scope }); // Do not wait
+    await setTimeout(1); // Async nature of mutations
+    expect(scope.getState(query.$data)).toEqual('initial');
+    expect(scope.getState(query.$stale)).toBeTruthy();
+
+    await allSettled(scope);
+    expect(scope.getState(query.$data)).toEqual('2');
+
+    expect(listeners.onStart).toBeCalledTimes(3); // 2 original and 1 by refetch
+    expect(listeners.onStart).toHaveBeenNthCalledWith(3, 2); // refetch uses latest params
+    expect(scope.getState(query.$stale)).toBeFalsy();
+  });
+
   test('refetch true causes query to be refetched with latest params', async () => {
     const query = createQuery({
       handler: vi

packages/core/src/update/update.ts

@@ -49,15 +49,15 @@ export function update<
   Q extends Query<any, any, any, any>,
   M extends Mutation<any, any, any>,
   BySuccessSource = void,
-  ByFailureSource = void,
+  ByFailureSource = void
 >(
   query: Q,
   {
     on: mutation,
     by: rules,
   }: {
     on: M;
-    by: {
+    by?: {
       success: DynamicallySourcedField<
         {
           query: QueryState<Q>;
@@ -94,12 +94,14 @@ export function update<
     refetch?: Refetch<Q>;
   }>();
 
+  const success = rules?.success || (() => ({ error: null, refetch: true }));
+
   split({
     source: sample({
       clock: mutation.finished.success,
       source: {
         partialRule: normalizeSourced({
-          field: rules.success,
+          field: success,
         }),
         queryState: $queryState,
       },
@@ -115,7 +117,7 @@ export function update<
     cases: { fillData: fillQueryData, __: fillQueryError },
   });
 
-  if (rules.failure) {
+  if (rules?.failure) {
     split({
       source: sample({
         clock: mutation.finished.failure,