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

[samtsangbiz]

[REQUIRED] Environment info

firebase-tools: 15.0.0 (latest as of December 2025)

Platform: macOS

firebase-admin version: 13.6.0 (latest as of November 2025)

Node.js version: 20.17 (or your version)

Tested in Data Connect emulator only.

[REQUIRED] Test case

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

enum TickerStatus {
  PRIMARY
  ACTIVE
  HISTORICAL
}

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

Minimal Node.js script:

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();

[REQUIRED] Actual behavior
The operation fails with a GraphQL error:
textcannot represent non-enum value: PRIMARY
(or similar: "Expected type TickerStatus!, found "PRIMARY"")

Full error example (approximate):

JSON{
  "errors": [
    {
      "message": "Cannot represent non-enum value: \"PRIMARY\" as enum type TickerStatus!",
      "locations": [...],
      "path": [...]
    }
  ]
}
This indicates the SDK is serializing the enum value as an inline quoted string (status: "PRIMARY") in the generated mutation, which GraphQL cannot coerce to an enum literal when passed inline.
Workaround: Using executeGraphql with explicitly typed variables works:
TypeScriptconst mutation = `
  mutation InsertTicker($status: TickerStatus!) {
    ticker_insert(data: { symbol: "TEST", status: $status }) {
      symbol
    }
  }
`;

await dc.executeGraphql(mutation, {
  variables: { status: "PRIMARY" }
});

Thank you for looking into this! This limitation affects bulk data seeding for schemas using enums.

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[aalej]

Thanks for the detailed report @samtsangbiz! I'm trying this out and from what I can tell, the issue might be with the firebase-admin SDK. When changing the the code to use executeGraphql instead of insert, something like below

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

process.env.DATA_CONNECT_EMULATOR_HOST = "127.0.0.1:9399";
initializeApp({
    projectId: "demo-project"
})

const dc = getDataConnect({
    location: "us-central1", // or your location
    serviceId: "test-dc-2",
    connector: "default"
});

async function testInsert() {
    // this part
    const res = await dc.executeGraphql(`mutation { ticker_insert(data: { symbol: "cat", status: ACTIVE }) }`) // status value has no double-qoutes
    console.log(res)
}

testInsert();

The mutation is able to run without any issues and outputs:

{ data: { ticker_insert: { id: '09d38c533bba4574a99b146f3d27dbd9' } } }

Since executeGraphql works, I'm guessing this issue is occurring because under the hood the insert method of Firebase Admin SDK isn't correctly formatting the GraphQL mutation, which is similar to what you've observed. Could you please open up an issue in the firebase-admin-node repository?

I'll go ahead and close this since this seems to be an issue with the Firebase Admin SDK, however if you think this is an issue with Firebase Tools, feel free to leave a comment so that we can re-open this.

[samtsangbiz]

Thank you, I will reopen this bug in firebase-admin-node repository.