fix(firestore): Read user data from pipeline in union stage (#9765)

dlarocque · web-flow · commit 334b266fec0f · 2026-03-26T13:03:52.000-04:00
diff --git a/.changeset/stupid-turtles-grow.md b/.changeset/stupid-turtles-grow.md
@@ -0,0 +1,5 @@
+---
+'@firebase/firestore': patch
+---
+
+Read user data from pipeline in union stage. Fixes [GitHub Issue #9764](https://github.com/firebase/firebase-js-sdk/issues/9764)
diff --git a/packages/firestore/src/lite-api/stage.ts b/packages/firestore/src/lite-api/stage.ts
@@ -626,6 +626,7 @@ export class Union extends Stage {
   }
 
   _readUserData(context: ParseContext): void {
+    this.other._readUserData(context);
     super._readUserData(context);
   }
 }
diff --git a/packages/firestore/test/integration/api/pipeline.test.ts b/packages/firestore/test/integration/api/pipeline.test.ts
@@ -1910,6 +1910,35 @@ apiDescribe.skipClassic('Pipelines', persistence => {
         );
       });
 
+      it('run pipeline with user data with union', async () => {
+        const snapshot = await execute(
+          firestore
+            .pipeline()
+            .collection(randomCol.path)
+            .union(
+              firestore
+                .pipeline()
+                .collection(randomCol.path)
+                .where(equal('title', "The Hitchhiker's Guide to the Galaxy"))
+            )
+            .sort(field(documentIdFieldPath()).ascending())
+        );
+        expectResults(
+          snapshot,
+          'book1',
+          'book1',
+          'book10',
+          'book2',
+          'book3',
+          'book4',
+          'book5',
+          'book6',
+          'book7',
+          'book8',
+          'book9'
+        );
+      });
+
       it('supports options', async () => {
         const snapshot = await execute(
           firestore
diff --git a/packages/firestore/test/lite/pipeline.test.ts b/packages/firestore/test/lite/pipeline.test.ts
@@ -1898,6 +1898,35 @@ describe.skipClassic('Firestore Pipelines', () => {
         );
       });
 
+      it('run pipeline with user data with union', async () => {
+        const snapshot = await execute(
+          firestore
+            .pipeline()
+            .collection(randomCol.path)
+            .union(
+              firestore
+                .pipeline()
+                .collection(randomCol.path)
+                .where(equal('title', "The Hitchhiker's Guide to the Galaxy"))
+            )
+            .sort(field(documentIdFieldPath()).ascending())
+        );
+        expectResults(
+          snapshot,
+          'book1',
+          'book1',
+          'book10',
+          'book2',
+          'book3',
+          'book4',
+          'book5',
+          'book6',
+          'book7',
+          'book8',
+          'book9'
+        );
+      });
+
       it('supports options', async () => {
         const snapshot = await execute(
           firestore

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +'@firebase/firestore': patch
 +---
++
 +Read user data from pipeline in union stage. Fixes [GitHub Issue #9764](https://github.com/firebase/firebase-js-sdk/issues/9764)
Original file line number	Diff line number	Diff line change
`@@ -626,6 +626,7 @@ export class Union extends Stage {`
`626`	`626`	`}`
`627`	`627`
`628`	`628`	`_readUserData(context: ParseContext): void {`
	`629`	`+ this.other._readUserData(context);`
`629`	`630`	`super._readUserData(context);`
`630`	`631`	`}`
`631`	`632`	`}`