Setting a DocumentReference in Document on Firestore (NodeJS)

Question

I am trying to create a doc with a reference on Firestore with NodeJS v8.6.0. Like this

const admin = require('firebase-admin')
admin.initializeApp({ credential: MY_CREDENTIAL, databaseURL: MY_DB_URL })
const db = admin.firestore()

const ref = db.doc('foo/someDoc')
db.doc('bar/targetDoc').set({ link: ref })

Although ref is a DocumentReference, it results

Error: Argument "data" is not a valid Document. Input object is deeper than 20 levels or contains a cycle.

Is there anyway to do it on NodeJS (Admin)SDK?

---

In addition, the package used in the code is

"firebase-admin": "^5.4.1"

and

console.log(ref)

outputs

DocumentReference {
  _firestore: 
   Firestore {
     makeAuthenticatedRequest: 
      { [Function: makeAuthenticatedRequest]
        getCredentials: [Function: bound getCredentials],
        authClient: [Object] },
     authClient: 
      Auth {
        authClientPromise: null,
        authClient: null,
        config: [Object],
        environment: {} },
     baseUrl: undefined,
     getCredentials: [Function: bound getCredentials],
     globalInterceptors: [],
     interceptors: [],
     packageJson: 
      { name: '@google-cloud/firestore',
        version: '0.8.1',
        author: 'Google Inc.',
        description: 'Firestore Client Library for Node.js',
        contributors: [Array],
        main: './src/index.js',
        files: [Array],
        repository: 'googleapis/nodejs-firestore',
        keywords: [Array],
        dependencies: [Object],
        devDependencies: [Object],
        scripts: [Object],
        license: 'Apache-2.0',
        engines: [Object],
        types: './types/firestore.d.ts' },
     projectId: 'MY_PROJECT',
     projectIdRequired: true,
     Promise: [Function: Promise],
     grpcMetadata: Metadata { _internal_repr: [Object] },
     maxRetries: undefined,
     userAgent: 'gcloud-node-firestore/0.8.1',
     activeServiceMap_: Map {},
     protos: {},
     _preferTransactions: false,
     _lastSuccessfulRequest: null,
     api: { Firestore: [Object] },
     _referencePath: 
      ResourcePath {
        segments: [],
        _formattedName: undefined,
        _projectId: 'dewpod-dev',
        _databaseId: '(default)' },
     app: 
      FirebaseApp {
        firebaseInternals_: [Object],
        services_: [Object],
        isDeleted_: false,
        name_: '[DEFAULT]',
        options_: [Object],
        database: [Function: bound ],
        auth: [Function: bound ],
        messaging: [Function: bound ],
        storage: [Function: bound ],
        firestore: [Function: bound ],
        INTERNAL: [Object] },
     INTERNAL: FirestoreInternals {} },
  _referencePath: 
   ResourcePath {
     segments: [ 'orgs', 'fooOrg' ],
     _formattedName: undefined,
     _projectId: 'dewpod-dev',
     _databaseId: '(default)' } }

and the full error message is

/SOME_PATH/node_modules/@google-cloud/firestore/src/validate.js:86
        throw new Error(message);
        ^

Error: Argument "data" is not a valid Document. Input object is deeper than 20 levels or contains a cycle.
    at Object.exports.(anonymous function) [as isDocument] (/SOME_PATH/node_modules/@google-cloud/firestore/src/validate.js:86:15)
    at WriteBatch.set (/SOME_PATH/node_modules/@google-cloud/firestore/src/write-batch.js:251:14)
    at DocumentReference.set (/SOME_PATH/node_modules/@google-cloud/firestore/src/reference.js:416:8)
    at Object.<anonymous> (/SOME_PATH/fstest.js:17:20)
    at Module._compile (module.js:624:30)
    at Object.Module._extensions..js (module.js:635:10)
    at Module.load (module.js:545:32)
    at tryModuleLoad (module.js:508:12)
    at Function.Module._load (module.js:500:3)
    at Function.Module.runMain (module.js:665:10)

Answer 1

This was a bug in an interaction between the admin SDK and the regular node SDK for Firestore.

An update to @google-cloud/firestore 0.8.2 should fix this issue.

You can update your project with npm update to get this change.