Add toJSON() support for Firestore classes (#4298)

Author: Brian Chen

.changeset/clean-meals-double.md

@@ -0,0 +1,7 @@
+---
+'@firebase/app-compat': patch
+'@firebase/app': patch
+'@firebase/firestore': patch
+---
+
+Firestore classes like DocumentReference and Query can now be serialized to JSON (#4258)

packages-exp/app-compat/src/firebaseApp.ts

@@ -134,6 +134,14 @@ export class FirebaseAppImpl implements FirebaseApp {
   _addOrOverwriteComponent(component: Component): void {
     _addOrOverwriteComponent(this.app, component);
   }
+
+  toJSON(): object {
+    return {
+      name: this.name,
+      automaticDataCollectionEnabled: this.automaticDataCollectionEnabled,
+      options: this.options
+    };
+  }
 }
 
 // TODO: investigate why the following needs to be commented out

packages/app/src/firebaseApp.ts

@@ -163,6 +163,14 @@ export class FirebaseAppImpl implements FirebaseApp {
     this.container.addOrOverwriteComponent(component);
   }
 
+  toJSON(): object {
+    return {
+      name: this.name,
+      automaticDataCollectionEnabled: this.automaticDataCollectionEnabled,
+      options: this.options
+    };
+  }
+
   /**
    * This function will throw an Error if the App has already been deleted -
    * use before performing API actions on the App.

packages/app/src/lite/firebaseAppLite.ts

@@ -141,4 +141,12 @@ export class FirebaseAppLiteImpl implements FirebaseApp {
       throw ERROR_FACTORY.create(AppError.APP_DELETED, { appName: this.name_ });
     }
   }
+
+  toJSON(): object {
+    return {
+      name: this.name,
+      automaticDataCollectionEnabled: this.automaticDataCollectionEnabled,
+      options: this.options
+    };
+  }
 }

packages/app/test/firebaseApp.test.ts

@@ -336,6 +336,11 @@ function firebaseAppTests(
       expect(() => firebase.app('toString')).throws(/'toString'.*created/i);
     });
 
+    it('JSON.stringify() does not throw', () => {
+      const app = firebase.initializeApp({}, 'new-app');
+      JSON.stringify(app);
+    });
+
     describe('Check for bad app names', () => {
       const tests = ['', 123, false, null];
       for (const data of tests) {

packages/firestore/src/exp/snapshot.ts

@@ -214,9 +214,9 @@ export interface DocumentChange<T = DocumentData> {
  * access will return 'undefined'. You can use the `exists()` method to
  * explicitly verify a document's existence.
  */
-export class DocumentSnapshot<T = DocumentData> extends LiteDocumentSnapshot<
-  T
-> {
+export class DocumentSnapshot<
+  T = DocumentData
+> extends LiteDocumentSnapshot<T> {
   private readonly _firestoreImpl: FirebaseFirestore;
 
   /**
@@ -329,9 +329,9 @@ export class DocumentSnapshot<T = DocumentData> extends LiteDocumentSnapshot<
  * `exists` property will always be true and `data()` will never return
  * 'undefined'.
  */
-export class QueryDocumentSnapshot<T = DocumentData> extends DocumentSnapshot<
-  T
-> {
+export class QueryDocumentSnapshot<
+  T = DocumentData
+> extends DocumentSnapshot<T> {
   /**
    * Retrieves all fields in the document as an `Object`.
    *

packages/firestore/src/lite/database.ts

@@ -134,6 +134,14 @@ export class FirebaseFirestore implements FirestoreService {
     return this._terminateTask;
   }
 
+  toJSON(): object {
+    return {
+      app: this._app,
+      databaseId: this._databaseId,
+      settings: this._settings
+    };
+  }
+
   /**
    * Terminates all components used by this client. Subclasses can override
    * this method to clean up their own dependencies, but must also call this

packages/firestore/src/lite/snapshot.ts

@@ -212,9 +212,9 @@ export class DocumentSnapshot<T = DocumentData> {
  * `exists` property will always be true and `data()` will never return
  * 'undefined'.
  */
-export class QueryDocumentSnapshot<T = DocumentData> extends DocumentSnapshot<
-  T
-> {
+export class QueryDocumentSnapshot<
+  T = DocumentData
+> extends DocumentSnapshot<T> {
   /**
    * Retrieves all fields in the document as an `Object`.
    *

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

@@ -155,9 +155,7 @@ apiDescribe('Queries', (persistence: boolean) => {
         .onSnapshot(storeLimitEvent.storeEvent);
 
       // Setup mirroring `limitToLast` query
-      const storeLimitToLastEvent = new EventsAccumulator<
-        firestore.QuerySnapshot
-      >();
+      const storeLimitToLastEvent = new EventsAccumulator<firestore.QuerySnapshot>();
       let limitToLastUnlisten = collection
         .orderBy('sort', 'desc')
         .limitToLast(2)

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

@@ -53,9 +53,7 @@ apiDescribe('Firestore', (persistence: boolean) => {
       docSnapshot = querySnapshot.docs[0];
       expect(docSnapshot.data()).to.deep.equal(data);
 
-      const eventsAccumulator = new EventsAccumulator<
-        firestore.QuerySnapshot
-      >();
+      const eventsAccumulator = new EventsAccumulator<firestore.QuerySnapshot>();
       const unlisten = collection.onSnapshot(eventsAccumulator.storeEvent);
       querySnapshot = await eventsAccumulator.awaitEvent();
       docSnapshot = querySnapshot.docs[0];