[Data Connect] Admin SDK bulk insert/insertMany fails to serialize enum values correctly (GraphQL coercion error)

[samtsangbiz]

[READ] Step 1: Are you in the right place?

• For issues related to the code in this repository file a Github issue.
• If the issue pertains to Cloud Firestore, read the instructions in the "Firestore issue"
  template.
• For general technical questions, post a question on StackOverflow
  with the firebase tag.
• For general Firebase discussion, use the firebase-talk
  google group.
• For help troubleshooting your application that does not fall under one
  of the above categories, reach out to the personalized
  Firebase support channel.

[REQUIRED] Step 2: Describe your environment

• Operating System version: macOS
• Firebase SDK version: firebase-admin 13.6.0
• Firebase Product: Data Connect
• Node.js version: 24.12
• NPM version: 11.6.2

[REQUIRED] Step 3: Describe the problem

Steps to reproduce:

1. Use the minimal GraphQL schema with an enum and a table referencing it.

2. Initialize the Firebase Admin app and get a Data Connect instance (optionally connect to the Data Connect emulator).

3. Attempt to insert a row using dc.insert("ticker", { symbol: "TEST", status: "PRIMARY" }).

The operation fails with a GraphQL validation error indicating that the enum value is being sent as a quoted string instead of an unquoted enum literal.

Tested only in the Data Connect emulator.

Relevant Code:

Minimal schema (dataconnect/schema/schema.graphql):

enum TickerStatus {
  PRIMARY
  ACTIVE
  HISTORICAL
}

type Ticker @table {
  symbol: String!
  status: TickerStatus!
}

Minimal Node.js script to reproduce:

import { getDataConnect } from "firebase-admin/data-connect";
import admin from "firebase-admin";

admin.initializeApp();

// For emulator testing:
// process.env.DATA_CONNECT_EMULATOR_HOST = "127.0.0.1:9399";

const dc = getDataConnect({
  location: "us-west2", // or your location
  serviceId: "your-service-id",
});

async function testInsert() {
  try {
    await dc.insert("ticker", {
      symbol: "TEST",
      status: "PRIMARY", // string matching enum literal
    });
    console.log("Success");
  } catch (error) {
    console.error("Error:", error);
  }
}

testInsert();

Additional environment info:

• firebase-tools: 15.0.0

Actual behavior

The insert fails with a GraphQL error such as:

"Cannot represent non-enum value: \"PRIMARY\" as enum type TickerStatus!"

or similar ("Expected type TickerStatus!, found "PRIMARY"").

This suggests that the Admin SDK is serializing the enum value as an inline quoted string in the generated mutation (e.g., status: "PRIMARY"), which GraphQL servers reject for enum types (enums must be unquoted literals when sent inline).

Expected behavior

The insert should succeed, with the SDK properly handling enum values by sending them as unquoted enum literals in the mutation payload.

This limitation impacts bulk data seeding and administrative scripts that rely on the convenient insert/update methods for schemas with enums. Thank you for investigating!

[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.

[dconeybe]

@stephenarosaj Would this be an issue you have some background information on?

[stephenarosaj]

Yes, thanks @dconeybe! And thanks @samtsangbiz for the bug report :)

I've investigated a bit and can confirm that this bug is present, but only in a portion of our API. The following methods improperly serialize the enum value:

• insert
• insertMany
• upsert
• upsertMany

We'll handle the underlying bug and provide an update here when it's fixed. In the meantime, the rest of the API serializes enums properly - so if you'd like a workaround, please use any of the following methods:

• Instead of using any of the following APIs directly, you can use the Generated Admin SDK with your existing Data Connect schema (requires defining operations in your GraphQL files - documentation)
• executeQuery (requires defining a query in your GraphQL files)
• executeMutation (requires defining a mutation in your GraphQL files)
• executeGraphql (for arbitrary GraphQL strings - documentation)
• executeGraphqlRead (for arbitrary GraphQL strings - documentation)

Thanks again for the bug report :)