Exception thrown from thin mode connection finalizer

[sharadraju]

Discussed in #1748

^{Originally posted by gcowan-ot August 9, 2025}
I'm seeing an issue with version 6.8+ when a thin mode connection attempt fails. When the subsequent finalizer runs, an exception is thrown. My service implementation will try connecting with thick mode when the connection fails. The thick mode connection is successful but the service is left in an potentially unstable state due to the thin mode connection finalizer exception. Has anyone else seen this?

finalizer from connection.js
const finalizationRegistry = new global.FinalizationRegistry((heldValue) => {
heldValue.disconnect();
});

exception that is thrown...

C:\iv\oracle-connect\node_modules\oracledb\lib\thin\sqlnet\networkSession.js:640
if (type != constants.NSFIMM && !this.ntAdapter.err) {
^

TypeError: Cannot read properties of null (reading 'err')
at NetworkSession.disconnect (C:\iv\oracle-connect\node_modules\oracledb\lib\thin\sqlnet\networkSession.js:640:53)
at C:\iv\oracle-connect\node_modules\oracledb\lib\thin\connection.js:47:13
at FinalizationRegistry.cleanupSome ()

reason for connection failure

Error: NJS-533: Advanced Networking Option service negotiation failed. Native Network Encryption and DataIntegrity only supported in node-oracledb thick mode.
Cause: ORA-12660
Help: https://docs.oracle.com/error-help/db/ora-12660
at Object.throwErrWithORAError (C:\iv\oracle-connect\node_modules\oracledb\lib\errors.js:746:17)
at ANO.processPacket (C:\iv\oracle-connect\node_modules\oracledb\lib\thin\sqlnet\ANO.js:419:16)
at NetworkSession.connect2 (C:\iv\oracle-connect\node_modules\oracledb\lib\thin\sqlnet\networkSession.js:316:17)
at process.processTicksAndRejections (node:internal/process/task_queues:105:5)
at async NetworkSession.connect1 (C:\iv\oracle-connect\node_modules\oracledb\lib\thin\sqlnet\networkSession.js:336:23)
at async NetworkSession.connect (C:\iv\oracle-connect\node_modules\oracledb\lib\thin\sqlnet\networkSession.js:617:5)
at async ThinConnectionImpl.connect (C:\iv\oracle-connect\node_modules\oracledb\lib\thin\connection.js:778:5)
at async Object.getConnection (C:\iv\oracle-connect\node_modules\oracledb\lib\oracledb.js:771:3)
at async Object.getConnection (C:\iv\oracle-connect\node_modules\oracledb\lib\util.js:271:16)
at async tryOracleConnect (C:\iv\oracle-connect\src\oc.js:12:18) {
code: 'NJS-533'
}