Return Firestore-Compat types from QuerySnapshot.docs

Author: schmidt-sebastian

packages/firestore/src/api/database.ts

@@ -967,8 +967,11 @@ export class QueryDocumentSnapshot<T = PublicDocumentData>
 export class Query<T = PublicDocumentData>
   extends Compat<ExpQuery<T>>
   implements PublicQuery<T> {
+  private readonly _userDataWriter: UserDataWriter;
+
   constructor(readonly firestore: Firestore, delegate: ExpQuery<T>) {
     super(delegate);
+    this._userDataWriter = new UserDataWriter(firestore);
   }
 
   where(
@@ -1076,7 +1079,18 @@ export class Query<T = PublicDocumentData>
     } else {
       query = getDocs(this._delegate);
     }
-    return query.then(result => new QuerySnapshot(this.firestore, result));
+    return query.then(
+      result =>
+        new QuerySnapshot(
+          this.firestore,
+          new ExpQuerySnapshot<T>(
+            this.firestore._delegate,
+            this._userDataWriter,
+            this._delegate,
+            result._snapshot
+          )
+        )
+    );
   }
 
   onSnapshot(observer: PartialObserver<PublicQuerySnapshot<T>>): Unsubscribe;

packages/firestore/test/integration/api/type.test.ts

@@ -32,12 +32,18 @@ apiDescribe('Firestore', (persistence: boolean) => {
     db: firestore.FirebaseFirestore,
     data: {}
   ): Promise<void> {
-    const doc = db.collection('rooms').doc();
+    const collection = db.collection(db.collection('a').doc().id);
+    const doc = collection.doc();
     return doc
       .set(data)
       .then(() => doc.get())
-      .then(snapshot => {
-        expect(snapshot.data()).to.deep.equal(data);
+      .then(docSnapshot => {
+        expect(docSnapshot.data()).to.deep.equal(data);
+        return collection.get();
+      })
+      .then(querySnapshot => {
+        const [docSnapshot] = querySnapshot.docs;
+        expect(docSnapshot.data()).to.deep.equal(data);
       });
   }
 

packages/firestore/test/util/equality_matcher.ts

@@ -16,6 +16,7 @@
  */
 
 import { use } from 'chai';
+import { Indexable } from '../../src/util/misc';
 
 /**
  * Duck-typed interface for objects that have an isEqual() method.
@@ -57,6 +58,15 @@ function customDeepEqual(
       return customMatcher.equalsFn(left, right);
     }
   }
+  if (left && typeof left === 'object' && right && typeof right === 'object') {
+    // The `isEqual` check below returns true if firestore-exp types are
+    // compared with API types from Firestore classic. We do want to
+    // differentiate between these types in our tests to ensure that the we do
+    // not return firestore-exp types in the classic SDK.
+    if ((left as Indexable).constructor !== (right as Indexable).constructor) {
+      return false;
+    }
+  }
   if (typeof left === 'object' && left && 'isEqual' in left) {
     return (left as Equatable<unknown>).isEqual(right);
   }