ci(test): add Pytest (databricks) lane for the databricks extra

The `databricks` extra (psycopg / databricks-sdk / mlflow) isn't installed
on the standard pytest lanes (they use `--extra all --extra dev`, which has
databricks-sdk but not psycopg). So a test that builds a postgresql+psycopg
engine or calls the Databricks SDK fails with `ModuleNotFoundError: psycopg`
on the catch-all `misc` lane.

Add a `databricks` pytest marker and a dedicated `Pytest (databricks)` lane
that installs `--extra databricks` and runs `-m databricks`. The standard
lanes now run `-m "not databricks"`, so marked tests are deselected there
and selected only in the new lane. Register the marker in pyproject and gate
the lane in merge-ready's required checks.

Decouples the upcoming Lakebase token-engine tests (psycopg-dependent) from
the lean lanes via the @pytest.mark.databricks decorator.

Co-authored-by: Isaac

.github/scripts/merge-ready/required.sh

@@ -21,6 +21,7 @@ REQUIRED=(
   "Pytest (server-rest)"
   "Pytest (spec-llms)"
   "Pytest (misc)"
+  "Pytest (databricks)"
   "E2E Tests (shard 0/4)"
   "E2E Tests (shard 1/4)"
   "E2E Tests (shard 2/4)"
@@ -47,6 +48,7 @@ ALLOW_SKIP=(
   "Pytest (server-rest)"
   "Pytest (spec-llms)"
   "Pytest (misc)"
+  "Pytest (databricks)"
   "E2E Tests (shard 0/4)"
   "E2E Tests (shard 1/4)"
   "E2E Tests (shard 2/4)"

.github/workflows/ci.yml

@@ -112,6 +112,14 @@ jobs:
               --ignore=tests/spec
               --ignore=tests/llms
               --ignore=tests/codex_parity
+          # Databricks-coupled tests (Lakebase token engine, psycopg). This is
+          # the only lane that installs the `databricks` extra; the
+          # @pytest.mark.databricks marker keeps these tests off the lean lanes
+          # (which run -m "not databricks") and selects them here.
+          - group: databricks
+            paths: tests/db tests/deploy
+            extra: databricks
+            markexpr: databricks
 
     steps:
       - name: Check out repo
@@ -144,7 +152,9 @@ jobs:
           key: venv-${{ runner.os }}-${{ hashFiles('.python-version') }}-${{ hashFiles('uv.lock') }}
 
       - name: Install dependencies
-        run: uv sync --locked --extra all --extra dev
+        # matrix.extra (e.g. "databricks") adds an extra for lanes that need it;
+        # empty for the default lanes.
+        run: uv sync --locked --extra all --extra dev ${{ matrix.extra && format('--extra {0}', matrix.extra) || '' }}
 
       - name: Run pytest
         shell: bash
@@ -165,6 +175,7 @@ jobs:
           # shellcheck disable=SC2086
           env -u OPENAI_API_KEY -u ANTHROPIC_API_KEY -u DATABRICKS_TOKEN \
             uv run pytest ${{ matrix.paths }} \
+              -m "${{ matrix.markexpr || 'not databricks' }}" \
               -n ${{ matrix.workers || '8' }} \
               --dist=${{ matrix.dist || 'loadfile' }} \
               --timeout=${{ matrix.timeout || '300' }} \

pyproject.toml

@@ -301,6 +301,7 @@ pythonpath = [".", "sdks/python-client", "sdks/ui"]
 markers = [
     "live: end-to-end tests requiring real LLM API key (run with --llm-api-key)",
     "live_app: end-to-end tests requiring a deployed Databricks App server",
+    "databricks: requires the `databricks` extra (psycopg / databricks-sdk / mlflow). Deselected on the standard lanes via -m 'not databricks'; runs only in the Pytest (databricks) lane, which installs the extra. Use for tests that build a postgresql+psycopg engine or call the Databricks SDK.",
     "model(name, ...): one arg pins this test to that model overriding the suite-wide --model CLI default; multiple args fan the test out across all listed models via indirect parametrize.",
     "model_pinned: opt out of tests/_model_pools.py spreading and retry rotation; literal model strings are used as written.",
     "flaky(reruns=2, reruns_delay=0): rerun a nondeterministic test on failure (pytest-rerunfailures). Use for tests flaky due to timing/scheduling races (e.g. PTY drain timing), NOT real-LLM nondeterminism — those use llm_flaky, which rotates models per attempt.",