fix(sea): forward queryTags through executeStatement (was silently dropped)

`ExecuteStatementOptions.queryTags` is a public option but the SEA
executeStatement never forwarded it, so tags were silently dropped versus
the Thrift backend. Serialise them JS-side via `serializeQueryTags` into the
conf overlay's `query_tags` key (the same wire shape Thrift produces) — not
via the napi `queryTags` field, which is a `HashMap<String,String>` that
can't represent a null-valued tag, and the kernel rejects setting both the
field and a `query_tags` conf key. Null-valued tags round-trip as key-only
segments.

Co-authored-by: Isaac
Signed-off-by: Madhavendra Rathore <madhavendra.rathore@databricks.com>

Author: msrathore-db

lib/sea/SeaSessionBackend.ts

@@ -39,6 +39,7 @@ import { seaServerInfoValue } from './SeaServerInfo';
 import { buildSeaPositionalParams, buildSeaNamedParams } from './SeaPositionalParams';
 import ParameterError from '../errors/ParameterError';
 import { emptyToUndefined, countParameterMarkers } from './SeaInputValidation';
+import { serializeQueryTags } from '../utils';
 
 export interface SeaSessionBackendOptions {
   /** The opaque napi `Connection` handle returned by `openSession`. */
@@ -168,6 +169,16 @@ export default class SeaSessionBackend implements ISessionBackend {
     if (options.queryTimeout !== undefined) {
       nativeOptions.queryTimeoutSecs = Number(options.queryTimeout);
     }
+    // Query tags: serialise JS-side into the conf overlay's `query_tags` key
+    // (the same wire shape the Thrift backend produces via `serializeQueryTags`
+    // → `confOverlay`). Not forwarded via the napi `queryTags` field: that's a
+    // `HashMap<String,String>` which can't represent a null-valued tag, and the
+    // kernel rejects setting both the field and a `query_tags` conf key. A
+    // null-valued tag therefore round-trips as a key-only segment.
+    const serializedQueryTags = serializeQueryTags(options.queryTags);
+    if (serializedQueryTags !== undefined) {
+      nativeOptions.statementConf = { query_tags: serializedQueryTags };
+    }
     const hasOptions = Object.keys(nativeOptions).length > 0;
 
     let nativeStatement;

tests/unit/sea/execution.test.ts

@@ -379,6 +379,23 @@ describe('SeaSessionBackend', () => {
     expect(connection.lastOptions?.queryTimeoutSecs).to.equal(30);
   });
 
+  it('executeStatement serialises queryTags into statementConf.query_tags (Thrift wire shape)', async () => {
+    const connection = new FakeNativeConnection();
+    const session = makeSession(connection);
+    await session.executeStatement('SELECT 1', { queryTags: { team: 'data', env: 'prod' } });
+    expect(connection.lastOptions?.statementConf?.query_tags).to.equal('team:data,env:prod');
+    // Must NOT use the napi `queryTags` field (can't carry null tags; kernel
+    // rejects both field + conf key).
+    expect(connection.lastOptions?.queryTags).to.equal(undefined);
+  });
+
+  it('executeStatement carries a null-valued queryTag as a key-only segment', async () => {
+    const connection = new FakeNativeConnection();
+    const session = makeSession(connection);
+    await session.executeStatement('SELECT 1', { queryTags: { audited: null } });
+    expect(connection.lastOptions?.statementConf?.query_tags).to.equal('audited');
+  });
+
   it('executeStatement forwards namedParameters as napi namedParams ({name,sqlType,value})', async () => {
     const connection = new FakeNativeConnection();
     const session = makeSession(connection);