[Data Connect] getDataConnect() ignores connector field in cache key

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

Yes, this is a bug in the firebase-admin/data-connect module code.

[REQUIRED] Step 2: Describe your environment

• Operating System version: macOS / Linux
• Firebase SDK version: firebase-admin@13.x (all versions with Data Connect support)
• Firebase Product: Data Connect
• Node.js version: 24.x
• NPM version: 11.x

[REQUIRED] Step 3: Describe the problem

Summary

The DataConnectService.getDataConnect() method caches DataConnect instances using only location and serviceId as the cache key, ignoring the connector field from ConnectorConfig.

This causes incorrect behavior when using multiple connectors with the same Data Connect service.

Steps to reproduce:

1. Create a Data Connect service with multiple connectors (e.g., public, user, admin)
2. Call getDataConnect() with different connector configs that share the same location and serviceId
3. Observe that both calls return the same DataConnect instance

Expected behavior:

Each unique combination of location, serviceId, and connector should return a distinct DataConnect instance.

Actual behavior:

The second call returns the cached instance from the first call, ignoring the different connector value.

Relevant Code:

import { getDataConnect, ConnectorConfig } from 'firebase-admin/data-connect';

const publicConfig: ConnectorConfig = {
  location: 'us-west2',
  serviceId: 'my-service',
  connector: 'public',
};

const userConfig: ConnectorConfig = {
  location: 'us-west2',
  serviceId: 'my-service',
  connector: 'user',  // Different connector!
};

const publicDc = getDataConnect(publicConfig);
const userDc = getDataConnect(userConfig);

console.log(publicDc === userDc);  // true (BUG! Should be false)
console.log(userDc.connectorConfig.connector);  // 'public' (BUG! Should be 'user')

Impact:

When using multiple connectors (a common pattern for role-based access control), operations intended for one connector are incorrectly routed to another, causing "operation not found" errors.

Root cause:

In src/data-connect/data-connect.ts, line 39:

const id = `${connectorConfig.location}-${connectorConfig.serviceId}`;

The cache key should also include the connector field:

const id = `${connectorConfig.location}-${connectorConfig.serviceId}-${connectorConfig.connector ?? ''}`;

I have a fix ready with tests: #3055