fix(firestore-bigquery-export): fixed "Converting circular structure to JSON" error (issue #236).

firestore-bigquery-export/firestore-bigquery-change-tracker/package.json

@@ -5,7 +5,7 @@
     "url": "github.com/firebase/extensions.git",
     "directory": "firestore-bigquery-export/firestore-bigquery-change-tracker"
   },
-  "version": "1.1.2",
+  "version": "1.1.3",
   "description": "Core change-tracker library for Cloud Firestore Collection BigQuery Exports",
   "main": "./lib/index.js",
   "scripts": {
@@ -28,7 +28,8 @@
     "generate-schema": "^2.6.0",
     "inquirer": "^6.4.0",
     "lodash": "^4.17.14",
-    "sql-formatter": "^2.3.3"
+    "sql-formatter": "^2.3.3",
+    "traverse": "^0.6.6"
   },
   "devDependencies": {
     "typescript": "^3.4.5",

firestore-bigquery-export/firestore-bigquery-change-tracker/src/bigquery/index.ts

@@ -15,6 +15,8 @@
  */
 
 import * as bigquery from "@google-cloud/bigquery";
+import * as firebase from "firebase-admin";
+import * as traverse from "traverse";
 import { RawChangelogSchema, RawChangelogViewSchema } from "./schema";
 import { latestConsistentSnapshotView } from "./snapshot";
 
@@ -52,6 +54,7 @@ export class FirestoreBigQueryEventHistoryTracker
 
   async record(events: FirestoreDocumentChangeEvent[]) {
     await this.initialize();
+
     const rows = events.map((event) => {
       return {
         insertId: event.eventId,
@@ -60,20 +63,36 @@ export class FirestoreBigQueryEventHistoryTracker
           event_id: event.eventId,
           document_name: event.documentName,
           operation: ChangeType[event.operation],
-          data: JSON.stringify(event.data),
+          data: JSON.stringify(this.serializeData(event.data)),
         },
       };
     });
     await this.insertData(rows);
   }
 
+  serializeData(eventData: any) {
+    if (typeof eventData === "undefined") {
+      return undefined;
+    }
+
+    const data = traverse(eventData).map((property) => {
+      if (property instanceof firebase.firestore.DocumentReference) {
+        return property.path;
+      }
+
+      return property;
+    });
+
+    return data;
+  }
+
   /**
    * Inserts rows of data into the BigQuery raw change log table.
    */
   private async insertData(rows: bigquery.RowMetadata[]) {
     const options = {
       skipInvalidRows: false,
-      ignoreUnkownValues: false,
+      ignoreUnknownValues: false,
       raw: true,
     };
     try {

firestore-bigquery-export/package.json

@@ -13,7 +13,7 @@
   "author": "Jan Wyszynski <[email protected]>",
   "license": "Apache-2.0",
   "dependencies": {
-    "@firebaseextensions/firestore-bigquery-change-tracker": "^1.1.2",
+    "@firebaseextensions/firestore-bigquery-change-tracker": "^1.1.3",
     "@google-cloud/bigquery": "^2.1.0",
     "@types/chai": "^4.1.6",
     "chai": "^4.2.0",