toJSON methods warn of pending writes.

Author: DellaBitta

packages/firestore/src/api/snapshot.ts

@@ -42,6 +42,7 @@ import {
   QuerySnapshotBundleData
 } from '../util/bundle_builder_impl';
 import { Code, FirestoreError } from '../util/error';
+import { logWarn } from '../util/log';
 import { AutoId } from '../util/misc';
 
 import { Firestore } from './database';
@@ -520,6 +521,11 @@ export class DocumentSnapshot<
       document.data.value.mapValue.fields,
       'previous'
     );
+    if (documentData.hasPendingWrites) {
+      logWarn(
+        'DocumentSnapshot.toJSON serialized a document with pending writes. The pending writes will not be serialized.'
+      );
+    }
     builder.addBundleDocument(
       documentToDocumentSnapshotBundleData(
         this.ref.path,
@@ -703,6 +709,11 @@ export class QuerySnapshot<
         doc._document.data.value.mapValue.fields,
         'previous'
       );
+      if (documentData.hasPendingWrites) {
+        logWarn(
+          'QuerySnapshot.toJSON serialized a document with pending writes. The pending writes will not be serialized.'
+        );
+      }
       docBundleDataArray.push(
         documentToDocumentSnapshotBundleData(
           doc.ref.path,

packages/firestore/src/util/bundle_builder_impl.ts

@@ -107,7 +107,9 @@ export class BundleBuilder {
       : null;
 
     const neitherHasReadTime: boolean = !docReadTime && origDocReadTime == null;
-    const docIsNewer: boolean = docReadTime !== undefined && (origDocReadTime == null || origDocReadTime < docReadTime);
+    const docIsNewer: boolean =
+      docReadTime !== undefined &&
+      (origDocReadTime == null || origDocReadTime < docReadTime);
     if (neitherHasReadTime || docIsNewer) {
       // Store document.
       this.documents.set(docBundleData.documentPath, {
@@ -120,7 +122,7 @@ export class BundleBuilder {
           exists: docBundleData.documentExists
         }
       });
-    } 
+    }
     if (docReadTime && docReadTime > this.latestReadTime) {
       this.latestReadTime = docReadTime;
     }
@@ -176,12 +178,6 @@ export class BundleBuilder {
   private toBundleDocument(
     docBundleData: DocumentSnapshotBundleData
   ): ProtoDocument {
-    // TODO handle documents that have mutations
-    debugAssert(
-      !docBundleData.documentData.hasLocalMutations,
-      "Can't serialize documents with mutations."
-    );
-
     // a parse context is typically used for validating and parsing user data, but in this
     // case we are using it internally to convert DocumentData to Proto3 JSON
     const context = this.userDataReader.createContext(