FIX #3498 Query returns outdated result in second subscription

pubkey · Nov 23, 2021 · 21efd35 · 21efd35
1 parent 4f56a47
commit 21efd35
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -4,7 +4,7 @@
 
 Bugfixes:
   - LokiJS: Do not call `saveDatabase()` when no persistence adapter is given.
-
+  - Query returns outdated result in second subscription [#3498](https://github.com/pubkey/rxdb/issues/3498) Thanks [@swnf](https://github.com/swnf)
 ### 10.5.3 (19 November 2021)
 
 Bugfixes:

diff --git a/src/rx-query.ts b/src/rx-query.ts
@@ -8,7 +8,8 @@ import {
     mergeMap,
     filter,
     map,
-    tap
+    tap,
+    shareReplay
 } from 'rxjs/operators';
 import {
     sortObject,
@@ -46,7 +47,7 @@ import {
 } from './rx-document-prototype-merge';
 import { calculateNewResults } from './event-reduce';
 import { triggerCacheReplacement } from './query-cache';
-import { getStateSet, QueryMatcher } from 'event-reduce-js';
+import type { QueryMatcher } from 'event-reduce-js';
 import { _handleToStorageInstance } from './rx-collection-helper';
 
 let _queryCount = 0;
@@ -105,7 +106,10 @@ export class RxQueryBase<
                                 }
                             });
                     }),
-                    filter((docs: any[]) => !!docs), // not if previous returned false
+                    // not if previous returned false
+                    filter((docs: any[]) => !!docs),
+                    // copy the array so it wont matter if the user modifies it
+                    map((docs: any[]) => docs.slice(0)),
                     map((docs: any[]) => {
                         if (this.op === 'findOne') {
                             // findOne()-queries emit document or null
@@ -116,10 +120,9 @@ export class RxQueryBase<
                             return docs;
                         }
                     }),
-                    map(docs => {
-                        // copy the array so it wont matter if the user modifies it
-                        const ret = Array.isArray(docs) ? docs.slice() : docs;
-                        return ret;
+                    shareReplay({
+                        bufferSize: 1,
+                        refCount: true
                     })
                 ).asObservable();
 

diff --git a/test/unit.test.ts b/test/unit.test.ts
@@ -10,7 +10,6 @@ import './unit/rx-schema.test.js';
 import './unit/key-compression.test.js';
 import './unit/bug-report.test.js';
 import './unit/rx-database.test.js';
-import './unit/event-reduce.test.js'; // TODO move down under idle queue
 import './unit/rx-collection.test.js';
 import './unit/rx-document.test.js';
 import './unit/primary.test.js';
@@ -20,6 +19,7 @@ import './unit/cache-replacement-policy.test';
 import './unit/rx-query.test.js';
 import './unit/query-builder.test.js';
 import './unit/idle-queue.test.js';
+import './unit/event-reduce.test.js';
 import './unit/reactive-collection.test.js';
 import './unit/reactive-query.test.js';
 import './unit/reactive-document.test.js';

diff --git a/test/unit/rx-query.test.ts b/test/unit/rx-query.test.ts
@@ -1456,6 +1456,60 @@ config.parallel('rx-query.test.js', () => {
             assert.ok(res2);
             assert.strictEqual(resOne2.age, 42);
 
+            db.destroy();
+        });
+        it('#3498 RxQuery returns outdated result in second subscription', async () => {
+            const schema = {
+                version: 0,
+                primaryKey: 'id',
+                type: 'object',
+                properties: {
+                    id: {
+                        type: 'string'
+                    },
+                    field: {
+                        type: 'boolean'
+                    }
+                }
+            };
+            const db = await createRxDatabase({
+                name: randomCouchString(10),
+                storage: getRxStoragePouch('memory'),
+                eventReduce: true,
+                ignoreDuplicate: true
+            });
+            const collection = (await db.addCollections({
+                collection: {
+                    schema
+                }
+            })).collection;
+
+            const doc = await collection.insert({ id: 'testid', field: false });
+
+            // Bug only happens the second time the query is used
+            const result1 = await collection.find({ selector: { field: false } }).exec();
+            assert.strictEqual(result1.length, 1);
+
+            await doc.update({
+                $set: {
+                    field: true
+                }
+            });
+
+            const obs = collection.find({ selector: { field: false } }).$;
+            const result2a: any[][] = [];
+            const result2b: any[][] = [];
+            const sub2 = obs.subscribe((d) => result2b.push(d));
+            const sub1 = obs.subscribe((d) => result2a.push(d));
+
+            await promiseWait(5);
+
+            sub1.unsubscribe();
+            sub2.unsubscribe();
+
+            assert.strictEqual(Math.max(...result2a.map(r => r.length)), 0);
+            assert.strictEqual(Math.max(...result2b.map(r => r.length)), 0);
+
             db.destroy();
         });
     });