From 1aaf5205380e7c9d220fbc57b7f5b14d730fa1b0 Mon Sep 17 00:00:00 2001
From: Kim <kimgronqvist@gmail.com>
Date: Tue, 15 Oct 2024 22:07:31 +0200
Subject: [PATCH] Fix useQuery issue with initialData #75

---
 packages/mst-query/src/MstQueryHandler.ts  | 26 +++++++++++--------
 packages/mst-query/tests/mstQuery.test.tsx | 30 +++++++++++++++++++---
 2 files changed, 41 insertions(+), 15 deletions(-)

diff --git a/packages/mst-query/src/MstQueryHandler.ts b/packages/mst-query/src/MstQueryHandler.ts
index 7431026..73a8b8f 100644
--- a/packages/mst-query/src/MstQueryHandler.ts
+++ b/packages/mst-query/src/MstQueryHandler.ts
@@ -81,18 +81,20 @@ export class QueryObserver {
         if (this.isQuery) {
             options.isMounted = this.isMounted;
 
-            if (!options.isRequestEqual) {
-                this.query.setData(null);
-            }
-
-            if (!this.isMounted && options.initialData) {
-                const initialDataUpdatedAt = options.initialDataUpdatedAt ?? new Date();
-                if (!isDataStale(initialDataUpdatedAt, options.staleTime)) {
+            if (options.initialData) {
+                const isStale = isDataStale(options.initialDataUpdatedAt, options.staleTime);
+                if (!isStale) {
                     this.query.__MstQueryHandler.hydrate(options);
+                } else {
+                    this.query.__MstQueryHandler.queryWhenChanged(options);
+                }
+            } else {
+                if (!options.isRequestEqual) {
+                    this.query.setData(null);
                 }
-            }
 
-            this.query.__MstQueryHandler.queryWhenChanged(options);
+                this.query.__MstQueryHandler.queryWhenChanged(options);
+            }
         }
 
         if (!this.isMounted) {
@@ -546,6 +548,8 @@ export class MstQueryHandler {
     }
 }
 
-function isDataStale(cachedAt: number, staleTime: number = 0) {
-    return Date.now() - cachedAt >= staleTime;
+function isDataStale(cachedAt?: number, staleTime: number = 0) {
+    const now = Date.now();
+    const cachedTime = cachedAt ?? now;
+    return now - cachedTime >= staleTime;
 }
diff --git a/packages/mst-query/tests/mstQuery.test.tsx b/packages/mst-query/tests/mstQuery.test.tsx
index 119cfc6..f116953 100644
--- a/packages/mst-query/tests/mstQuery.test.tsx
+++ b/packages/mst-query/tests/mstQuery.test.tsx
@@ -854,31 +854,53 @@ test('useQuery should not run when initialData is passed and staleTime is larger
     let id = observable.box('test');
     const initialData = await api.getItem({ request: { id: id.get() } });
 
-    const loadingStates: boolean[] = [];
+    let loadingStates: boolean[] = [];
+    const isLoadingReaction = reaction(
+        () => q.itemQuery.isLoading,
+        (isLoading) => {
+            loadingStates.push(isLoading);
+        }
+    );
+
+    let dataStates: any[] = [];
+    const dataReaction = reaction(
+        () => q.itemQuery.data,
+        (data: any) => {
+            dataStates.push(data ? data.id : null);
+        }
+    );
+
     const Comp = observer(() => {
         const { query, isLoading } = useQuery(q.itemQuery, {
             initialData,
             request: { id: id.get() },
             staleTime: 10,
         });
-        loadingStates.push(isLoading);
         return <div></div>;
     });
     render(<Comp />);
 
     await wait(0);
 
-    expect(loadingStates).toEqual([false, false]);
+    expect(loadingStates).toEqual([]);
+    expect(dataStates).toEqual(["test"]);
     expect(q.itemQuery.data?.id).toBe('test');
 
     id.set('different-test');
     await wait(0);
-    expect(q.itemQuery.data?.id).toBe('different-test');
+
+    expect(q.itemQuery.data?.id).toBe('test');
     expect(q.itemQuery.variables.request?.id).toBe('different-test');
+    expect(loadingStates).toEqual([]);
+    expect(dataStates).toEqual(["test"]);
+    
+    isLoadingReaction();
+    dataReaction();
 
     configureMobx({ enforceActions: 'observed' });
 });
 
+
 test('useQuery should run when initialData is passed and initialDataUpdatedAt is older than staleTime', async () => {
     const { render, q } = setup();