[coverage] Conformance findings: SESSION-018

Start with the named failing test in the coverage PR under tests/ and inspect the Node.js driver's standard /api/2.0/sql/sessions CreateSession path. Confirm execution_mode=FAST is sent by default, then run the conformance case for SELECT 1 AS test_value and verify the session opens, executes, and closes with one row.

Summary

Surfaced by the multi-language coverage fan-out while conformance-testing these SPEC-IDs against databricks/databricks-sql-nodejs. Each finding is committed as an expected-failure (xfail) test in the coverage PR — the test asserts the CORRECT (post-fix) behavior and stays red until THIS driver (databricks/databricks-sql-nodejs) is fixed, then flips green as a tripwire.

Findings

• SESSION-018 [sea]: SEA CreateSession body omits execution_mode, so the session is not created in FAST mode; the driver sends only {warehouse_id} on POST /api/2.0/sql/sessions and therefore never receives server-issued session versions
  • failing test: sea session created in FAST execution mode — execution_mode=FAST on the standard /api/2.0/sql/sessions path [sea] (see the coverage PR diff under tests/)

Reproduce & Expected

SESSION-018 — Validates that a driver creating a SEA (Statement Execution API) session requests FAST execution mode BY DEFAULT and that the session it gets back opens, executes a query and closes normally.

Reproduce:

SELECT 1 AS test_value

Expected (per the shared spec):

• completes without an exception
• result has exactly 1 row(s)
• [sea] exactly 1 CreateSession call(s)
• [sea] CreateSession request execution_mode == 'FAST'

Context

• The behavior was first fixed in a DIFFERENT driver — reference PR: https://github.com/databricks/databricks-sql-kernel/pull/331 — which seeded the shared language-neutral spec. This issue tracks the same conformance gap in databricks/databricks-sql-nodejs; the reference PR is for cross-referencing the intended behavior, NOT a change to this repo.
• Coverage PR carrying the reproducing xfail test(s): https://github.com/databricks/databricks-driver-test/pull/1663