| name | flowfile-testing-and-validation |
| description | Exact per-package pytest/vitest/playwright commands, the 6 pytest markers and which need Docker, the test_utils Docker fixture matrix, the shared-test-DB isolation model and its failure modes, xfail/skip discipline, and coverage/CI test-matrix mechanics for the Flowfile monorepo. Use when running or writing tests, diagnosing "no such table" or phantom test failures, deciding whether a change is "validated," seeing XPASS in test output, wiring a new Docker-backed fixture, or asking "which suite proves this change works." |
Flowfile Testing and Validation
When NOT to use this skill
- Writing a new backend node or its tests →
flowfile-node-development.
- Debugging a specific failure you already reproduced (stack trace triage, log reading) →
flowfile-debugging-playbook.
- CI workflow authoring/release mechanics beyond test.yaml's test jobs (tagging, PyPI/Tauri release, Docker publish, branch protection) →
flowfile-change-control (release/tag mechanics, branch protection, publish pipelines).
- Env var reference beyond the handful that control test isolation (full
.env catalog, feature flags) → flowfile-config-and-flags.
- Known bugs / historical incidents not related to test infra itself →
flowfile-failure-archaeology.
- Local dev server startup, ports, Docker Compose for running the app (not testing it) →
flowfile-run-and-operate / flowfile-build-and-env.
If you just need "how do I run the core tests" — that's this skill, keep reading.
1. The single pytest config, and why bare pytest is dangerous
pyproject.toml [tool.pytest.ini_options] is the only pytest config for the monorepo (exception: flowfile_wasm/pytest.ini, scoped so cd flowfile_wasm && pytest runs only tests/python). There is no addopts, no testpaths, no norecursedirs.
Consequence: running bare pytest from repo root collects everything, including slow Docker-compose E2E tests (tests/integration) and Kafka tests (tests/kafka). Any doc claiming "pytest excludes these by default" is wrong at the config level — they're only skipped in practice because everyone targets a specific directory.
Rule: always pass an explicit directory. poetry run pytest flowfile_core/tests, never bare poetry run pytest.
The 6 registered markers (root CLAUDE.md's marker table is stale — it omits lsp)
markers = [
"worker: Tests for the flowfile_worker package",
"core: Tests for the flowfile_core package",
"kernel: Integration tests requiring Docker kernel containers",
"docker_integration: Full Docker-based E2E tests (require Docker, slow)",
"kafka: Integration tests requiring a Kafka/Redpanda broker (Docker)",
"lsp: Tests for the notebook LSP (Jedi) code-intelligence surface",
]
| Marker | Needs Docker? | Where used |
|---|
worker | No (marker only) | flowfile_worker package tests |
core | No (marker only) | flowfile_core package tests |
kernel | Yes | flowfile_core/tests -m kernel (76 tests); builds/runs kernel containers |
docker_integration | Yes | tests/integration — full docker-compose E2E |
kafka | Yes | tests/kafka, shared/tests/kafka — needs Redpanda |
lsp | No | flowfile_core/tests/lsp/test_lsp_routes.py (hermetic); test_lsp_kernel_integration.py also carries @pytest.mark.kernel |
Two more markers are used but not registered (pytest warns, doesn't fail): @pytest.mark.slow (flowfile_worker/tests/test_catalog_visualize.py), and slow/requires_yaml registered locally by tools/migrate/tests/conftest.py.
2. Run each suite — exact commands and prerequisites
All commands run from the repo root through the single Poetry env; there is no tox/nox.
| Suite | Command | Prerequisites / notes |
|---|
| core | poetry run pytest flowfile_core/tests | Autouse fixtures spawn worker + Postgres + MySQL. CI form: -m "not kernel". Worker-less: prefix SKIP_WORKER_TESTS=1. ~5,079 tests collected as of 2026-07-03 (v0.12.7), 76 of them kernel-marked. |
| worker | poetry run pytest flowfile_worker/tests | conftest sets TEST_MODE=1; Postgres on :5433 autouse (hard-fails if Docker is present but the container won't start). Cloud tests need MinIO/GCS/Azurite up. ~311 collected. |
| frame | poetry run pytest flowfile_frame/tests | conftest registers a minio-flowframe-test cloud connection at import; cloud tests need MinIO on :9000. ~620 collected. |
| scheduler | poetry run pytest flowfile_scheduler/tests | Fully hermetic — tmp SQLite per test, spawn stubbed, clock pinned. ~13 collected. |
| shared (no kafka) | poetry run pytest shared/tests --ignore=shared/tests/kafka | ~89 collected. |
| shared kafka | poetry run pytest shared/tests/kafka/ -v | session-autouse conftest starts/reuses Redpanda; skips without Docker. |
| kafka integration | poetry run pytest tests/kafka -m kafka | Needs Redpanda (auto-managed) + a running worker. |
| kernel (core-side) | poetry run pytest flowfile_core/tests -m kernel -v | Builds flowfile-kernel image unless FLOWFILE_KERNEL_IMAGE is preset; needs Docker. ~76 tests. |
| kernel_runtime unit | poetry run pytest kernel_runtime/tests | No Docker — TestClient only. ~327 collected. |
| docker E2E | poetry run pytest tests/integration -m docker_integration -v | Docker + compose v2; ports 63578/63579 must be free or tests skip; builds core+worker+kernel images (minutes). |
| auth Docker E2E | poetry run pytest flowfile_core/tests/test_auth_e2e.py -v -s | Builds real core image via the docker SDK directly (not compose); skips without Docker. |
| migrate tool | poetry run pytest tools/migrate/tests | ~64 collected; hermetic. |
| flowfile CLI | poetry run pytest flowfile/tests | test_api.py boots a real server via start_flowfile_server_process(); needs free ports. |
| coverage | make test_coverage | Core+worker sequential, --cov-append (see §5). |
| frontend unit | cd flowfile_frontend && npm run test:unit | Vitest, node env, no jsdom/happy-dom. ~30 test files. Watch mode: npm run test:unit:watch. |
| frontend E2E | cd flowfile_frontend && npm run test:web (web-flow only) or npm run test:all (adds canvas-overlays) | No webServer block in playwright.config.ts — core (:63578) and a Vite server must already be running. npx playwright install chromium first. Single worker, 2 retries in CI. |
| frontend E2E orchestrated | make test_e2e / make test_e2e_dev | Builds/starts core + preview(:4173) or dev(:8080), runs web-flow.spec.ts, then make stop_servers. The make target itself never fails on test failure (` |
| wasm JS | cd flowfile_wasm && npm run test:run | Vitest, happy-dom, globals on. ~348 cases. |
| wasm Python engine | cd flowfile_wasm && pip install -r tests/python/requirements.txt && python -m pytest tests/python | Own pytest.ini. Pins polars==1.18.0 / pydantic==2.10.5 / polars-expr-transformer==0.5.6 — the exact Pyodide 0.27.7 versions. Running through the monorepo Poetry env resolves a different Polars; use the pinned env for parity. ~85 test fns. |
| wasm Pyodide smoke | cd flowfile_wasm && npm install --no-save pyodide@0.27.7 parquet-wasm@0.7.1 && node tests/pyodide-smoke/smoke.cjs | The only guard for browser-namespace/bootstrap breakage — CPython tests can't catch it. |
Worked example — run only core tests, isolated from any other pytest session, without needing a worker:
FLOWFILE_DB_PATH=/tmp/ff_core_$$.db SKIP_WORKER_TESTS=1 \
poetry run pytest flowfile_core/tests -m "not kernel" -q
3. test_utils/ — the Docker fixture matrix
Package layout: test_utils/{postgres,mysql,s3,gcs,azurite,kafka}/, each with fixtures.py + commands.py. Every start_*/stop_* command is a Poetry script (poetry run start_postgres, poetry run stop_postgres, etc.) and all start_* commands exit 0 when Docker is missing — "return success to allow pipeline to continue" — so downstream tests just skip rather than the CI step failing.
| Service | Container name | Host port(s) | Started by | Skip behavior |
|---|
| Postgres | test-postgres-sample | 5433→5432 | poetry run start_postgres; core+worker conftest autouse (reuses if already listening) | is_docker_available() False → tests skipif; if Docker present but start fails → pytest.fail (core), soft-skip (worker uses same pattern but less strict) |
| MySQL | test-mysql-sample | 3307→3306 | poetry run start_mysql; core conftest autouse | Core: soft-fail with a log message, tests skip; image pull can take up to 300s first time |
| MinIO (S3) | test-minio-s3 | 9000 API, 9001 console | poetry run start_minio | _minio_available() / requires_minio guards; frame conftest assumes :9000 |
| GCS | test-fake-gcs | 4443 | poetry run start_gcs | is_gcs_available() guard; also re-populates data if container is up but empty |
| Azurite | test-azurite | 10000 (blob) | poetry run start_azurite | is_azurite_available() guard; well-known devstoreaccount1 creds hardcoded |
| Redpanda (Kafka) | test-redpanda-kafka | 19092→9092 | poetry run start_redpanda; tests/kafka + shared/tests/kafka conftest autouse | Skips without Docker; topics are UUID-suffixed per test so container reuse is safe |
Shared skip logic (every service's is_docker_available()):
- On macOS or Windows when
CI env is truthy → returns False (Docker treated as unavailable on non-Linux CI runners).
- Otherwise:
shutil.which("docker") must exist and docker info must exit 0 within 5s.
KEEP_MINIO_RUNNING / KEEP_GCS_RUNNING / KEEP_AZURITE_RUNNING / KEEP_REDPANDA_RUNNING (=true) keep a container alive after the managed context exits, for debugging.
flowfile_core/tests/flowfile_core_test_utils.py::is_docker_available() additionally returns False on Windows unconditionally (not just in CI).
4. State isolation model — and where it breaks
One SQLite DB per mode, resolved by shared/storage_config.py::get_database_url() (priority order, verified in code):
FLOWFILE_DB_PATH env var (explicit override) → sqlite:///$FLOWFILE_DB_PATHTESTING=True env var (exact string) → sqlite:///<storage.temp_directory>/test_flowfile_catalog.db — a fixed shared path- Default →
sqlite:///<storage.database_directory>/flowfile_catalog.db (the live DB)
Core conftest sets os.environ['TESTING'] = 'True' at import (flowfile_core/tests/conftest.py:23), before any flowfile_core import, so the test DB resolves correctly. Frame conftest does the same (flowfile_frame/tests/conftest.py:3).
Fragile point #1 (the one that will burn you): fixed shared test-DB path
Because step 2's path is fixed (not per-process), two concurrent pytest sessions on the same machine share test_flowfile_catalog.db. The session-scoped autouse setup_test_db fixture (flowfile_core/tests/conftest.py) calls init_db() on setup and, on teardown, does Base.metadata.drop_all(engine) then deletes the DB file. If session A tears down while session B is mid-run, B's tables vanish out from under it.
Symptom: a cascade of sqlite3.OperationalError: no such table: <catalog_table_read_links|users|...> that looks like your change broke 35 unrelated tests. It didn't — a second concurrent pytest process (yours from an earlier terminal, a background CI-simulation run, anything) tore down the shared DB mid-test.
The fix — highest-priority override, use it for every isolated run:
FLOWFILE_DB_PATH=/tmp/ff_$$.db poetry run pytest flowfile_core/tests -m "not kernel"
FLOWFILE_DB_PATH wins over TESTING in get_database_url(), so this fully isolates the DB per invocation. It also propagates to the worker subprocess the core conftest spawns (the worker inherits the pytest process env), so cross-boundary core↔worker tests stay isolated too — this is why the override is "complete," not partial.
Before blaming a code change for a wall of table-not-found errors, run ps aux | grep pytest and check for a second session.
Fragile point #2: never skip the startup migration for the test suite
flowfile_core/flowfile_core/database/init_db.py runs run_startup_migration() at import time unless FLOWFILE_SKIP_STARTUP_MIGRATION is set:
if not os.environ.get("FLOWFILE_SKIP_STARTUP_MIGRATION"):
run_startup_migration()
The core test suite's setup_test_db fixture depends on that import-time migration to create the schema in the first place. If you set FLOWFILE_SKIP_STARTUP_MIGRATION=1 while running flowfile_core/tests against a fresh/isolated FLOWFILE_DB_PATH, every test errors with no such table: users — there was never a migration run to create the tables.
FLOWFILE_SKIP_STARTUP_MIGRATION=1 is for diagnostics only — e.g. importing flowfile_core in a scratch script to inspect something without touching a real DB's migration stamp. Pair it with its own throwaway FLOWFILE_DB_PATH in that case, and never use it for pytest flowfile_core/tests.
FLOWFILE_DB_PATH=/tmp/fresh.db FLOWFILE_SKIP_STARTUP_MIGRATION=1 poetry run pytest flowfile_core/tests
FLOWFILE_DB_PATH=/tmp/fresh.db poetry run pytest flowfile_core/tests
SKIP_WORKER_TESTS=1
flowfile_core/tests/conftest.py's session-autouse flowfile_worker fixture checks os.environ.get("SKIP_WORKER_TESTS") == "1" and no-ops if set (no worker spawned, no reuse-probe). The execution_location fixture (parametrized ["local", "remote"], used by catalog/flow-API/run-node tests) then auto-skips its remote half. Use this to run core tests fast without a worker; do not use it when validating a core↔worker contract change (§6 below).
Other fragile points (verified in code, worth knowing)
- Catalog seed erosion: many core test modules call a
catalog_cleanup() helper that wipes all CatalogNamespace rows, including the init_db-seeded 'General' namespace. flowfile_core/tests/project/conftest.py has an autouse re-seed specifically to paper over this — a new suite depending on seeded catalog rows needs the same treatment.
- Worker virtual-result cache:
catalog_cleanup() also deletes .arrow files under the worker's virtual-results directory, because table-id recycling would otherwise let a stale cached file satisfy the next test's resolve.
- Session-global services: worker (:63579), Postgres (:5433), MySQL (:3307), Redpanda are reused if already listening — a dirty long-running instance from a previous session can leak state into a new run.
- Process-wide env mutation: the sharing test suite flips
FLOWFILE_MODE=docker via monkeypatch.setenv per test only — several core test modules construct a TestClient and mint auth tokens at import time under electron mode; flipping the mode process-wide before those imports breaks them.
- bcrypt monkeypatch: core conftest patches
bcrypt.hashpw at import to truncate >72-byte passwords (passlib/bcrypt compat) — password-hashing tests behave differently from a prod bcrypt install without it.
5. Coverage
- Source is core + worker only:
[tool.coverage.run] source = ["flowfile_core/flowfile_core", "flowfile_worker/flowfile_worker"] — frame, scheduler, and shared are deliberately excluded from coverage.
fail_under = 0 — coverage never gates a build by threshold.omit: */tests/*, */test_*, */__pycache__/*, */conftest.py.- No
branch=true, no dynamic_context — deliberate, because CI sets COVERAGE_CORE=sysmon (PEP-669 sys.monitoring tracer), which doesn't support those options.
Local:
make test_coverage
Core and worker run sequentially with --cov-append — the Makefile comment explains this avoids import collisions from both packages loading into one coverage-tracked process.
CI's dedicated coverage job (ubuntu, Python 3.12) sets COVERAGE_CORE: sysmon, runs core -m "not kernel" then worker, uploads coverage.xml/.coverage as an artifact, and pushes to Codecov (flags: backend, fail_ci_if_error: false — Codecov never blocks CI either). There is no codecov.yml in the repo; behavior is Codecov defaults.
6. Evidence bar — what "validated" means per change class
A green run is only as strong as what actually executed. Docker-gated suites silently skip without Docker/MinIO/etc — always ask "did the Postgres/MinIO/kernel tests actually run, or did they skip?" (check the pytest summary line for skip counts, not just "passed").
| Change class | Minimum bar |
|---|
| Core/worker/shared/frame backend change | Run the owning package's suite with an isolated DB: FLOWFILE_DB_PATH=/tmp/ff_$$.db poetry run pytest <pkg>/tests. Check skip counts didn't balloon vs. a baseline run. |
| Core ↔ worker contract change | Run without SKIP_WORKER_TESTS — the real worker subprocess must be exercised; execution_location-parametrized tests need it for their remote half. |
| DB schema change | Add flowfile_core/flowfile_core/alembic/versions/NNN_*.py, then poetry run pytest flowfile_core/tests/test_migration.py (builds DBs from scratch via FLOWFILE_DB_PATH). |
| Kernel-touching change | poetry run pytest flowfile_core/tests -m kernel locally with Docker running. |
flowfile_frame public API change | make stubs and stage the .pyi diff (do not commit it yourself — hand off per flowfile-change-control's no-agent-commit policy) — make check_stubs is a hard CI gate (regenerates then git diff --exit-code). |
| Kafka path change | poetry run pytest tests/kafka -m kafka plus shared/tests/kafka. |
| Frontend renderer change | npm run test:unit + npm run build:web (lint + vue-tsc --noEmit run inside the build script) — that's what CI's test-web job enforces. Canvas/flow behavior changes additionally need make test_e2e — read its Playwright output, the make exit code is unreliable (see §2). |
| WASM engine change | Pinned-env pytest (tests/python) and the Pyodide smoke test — a green CPython run does not prove the browser namespace still works. |
| Full-stack / deploy-shaped change | poetry run pytest tests/integration -m docker_integration -v with ports 63578/63579 free. |
7. xfail / XPASS discipline
Current inventory (verified live 2026-07-03, v0.12.7 — re-run before trusting, see §9):
| Location | What it claims | Live status |
|---|
flowfile_core/tests/flowfile/test_code_generator_edge_cases.py:201 (test_in_operator_numeric) | Flow's IN filter mishandles numeric-string quoting vs. codegen | STALE — XPASS. The bug was fixed elsewhere (filter logic moved to filter_expressions.py); the marker is dead weight. |
test_code_generator_edge_cases.py:459 (test_unique_without_columns) | Flow's unique(columns=[]) errors via an internal group_by needing ≥1 key; generated code is correct | Still xfail — real bug, flow is the buggy side. |
test_code_generator_edge_cases.py:766 (test_groupby_with_concat_aggregation) | Delimiter mismatch: generated str.concat() defaults to -, flow uses , | Still xfail — real bug, codegen side. |
flowfile_core/tests/flowfile/node_designer/test_node_designer.py:516 (TestNumericStringAliasBug) | data_types="numeric" string alias maps to Decimal only | STALE — XPASS. Already fixed; the test class + its "workaround" sibling test now document a bug that no longer exists. |
None of these four markers use strict=True, so CI shows XPASS silently and nobody notices.
Rule for this repo: XPASS means the xfail is stale. Delete the marker (and the outdated bug description) — never leave it, never "celebrate" the pass. When you add a new xfail for a real known bug, prefer @pytest.mark.xfail(reason=..., strict=True) so a future fix turns into a hard CI failure demanding the marker's removal, instead of a silent XPASS nobody notices.
Verification recipe (isolated DB, do not pair with FLOWFILE_SKIP_STARTUP_MIGRATION=1 — see §4):
FLOWFILE_DB_PATH=/tmp/xfail_probe.db poetry run pytest \
"flowfile_core/tests/flowfile/test_code_generator_edge_cases.py::TestBasicFilterOperators::test_in_operator_numeric" \
-q -p no:cacheprovider -rX
Other skip inventory:
flowfile_core/tests/flowfile/test_basic_filter.py:751,761 — unconditional pytest.mark.skip, "Manual input converts None to string; test requires actual null values from file sources." Product limitation, not test debt: is_null/is_not_null are effectively untested via manual-input at integration level.flowfile_worker/tests/test_train_apply_model.py:159 — benign parametrize carve-out (logistic_regression/knn_classifier need 0/1 targets; covered by a dedicated round-trip test elsewhere).- No
.skip/.todo/.fixme exist in any Playwright or Vitest spec (frontend or wasm) — the TS suites are clean of this pattern.
- The dominant "skip" pattern by volume is environment
skipif(not is_docker_available()) across core/worker/frame — dozens of uses. This is a coverage cliff, not debt: on a laptop without Docker+MinIO+emulators running, a large slice of integration surface silently skips, and a green local run is weak evidence of anything Docker-touching.
8. CI test matrix summary (test.yaml)
- Concurrency: group
${{ github.workflow }}-${{ github.ref }}, cancel-in-progress: ${{ github.event_name == 'pull_request' }} — PR runs cancel their own superseded runs; main-branch runs are never cancelled (docker-publish/release pipelines key off completed main builds). This is the only workflow file in the repo with a concurrency block.
detect-changes (dorny/paths-filter) gates every downstream job by which paths changed; workflow_dispatch input run_all_tests: true forces everything regardless.backend-tests matrix: fail-fast: false; ubuntu-latest × Python 3.10/3.11/3.12/3.13, plus macos-latest × 3.11. Starts Postgres/MySQL/MinIO/Azurite/GCS via the poetry run start_* scripts (no-op on macOS CI runners — Docker reports unavailable there). Core runs -m "not kernel".coverage: separate ubuntu/3.12 job, COVERAGE_CORE=sysmon (see §5).backend-tests-windows: windows-latest, Python 3.11 only, pwsh shell.kernel-tests: ubuntu/3.11, 15-min timeout, builds the kernel image, runs kernel_runtime unit tests then flowfile_core/tests -m kernel.check-stubs / check-formula-docs: drift gates — regenerate .pyi stubs / functions.md and fail on git diff.test-web: Vitest unit + build:web + preview-server curl check.docs-test: mkdocs build.test-summary: if: always(), aggregates all jobs except version-sync, fails if any non-skipped job failed. Treat this as the real pass/fail signal for the whole run — but note it is not wired into required branch-protection checks (a CI-mechanics fact, not this skill's territory beyond flagging it).
Separate, path-filtered workflows cover what test.yaml doesn't: e2e-tests.yml (Playwright web E2E), test-docker-auth.yml, test-kernel-integration.yml, test-docker-kernel-e2e.yml, test-kafka-integration.yml, flowfile-wasm-build.yml.
9. History — read this before "fixing" CI test speed again
The backend-tests (ubuntu, 3.12) job was ~56 minutes before 2026-06-20, caused by two compounding factors: coverage's default C-tracer roughly doubling runtime, and the core suite (~5k tests) running fully serially. Shipped fix (merged, do not re-litigate the same options without reading this first):
COVERAGE_CORE=sysmon — switched the coverage job to the PEP-669 sys.monitoring tracer, near-zero overhead on 3.12 vs. the old C-tracer's ~2x tax.- Coverage split into its own dedicated job — off the critical path of the functional matrix; the plain
backend-tests matrix jobs run without --cov at all.
- Dropped redundant frontend builds from backend jobs.
concurrency: cancel-in-progress for PR runs.
pytest-xdist was evaluated and explicitly deferred — do not casually re-propose it. Hard prerequisites that would need to be solved first, all rooted in the same fixed-DB-path problem as §4:
- Each xdist worker needs its own
FLOWFILE_DB_PATH, derived from PYTEST_XDIST_WORKER, and that derivation must happen before the first flowfile_core import — the DB engine binds to a URL at import time, so setting the env var after import is a no-op.
- If used on the coverage job:
parallel = true in [tool.coverage.run] plus a coverage combine step, neither of which exist today.
- Expected speedup is ~1.4–1.8x, not 2–4x, because several fixtures are shared-service singletons (the worker on :63579, Postgres on :5433, MySQL on :3307) that don't parallelize cleanly across workers without further isolation work.
Without those prerequisites, naive -n auto reproduces exactly the "no such table" cascade from §4 fragile point #1, at coverage-job scale — an empty or garbaged coverage.xml is the typical failure mode.
Load-bearing sleeps — do not remove these thinking they're dead time:
- Catalog test
time.sleep(1.05) calls exist because SQLite's updated_at column has 1-second granularity; a faster sleep produces flaky ordering assertions.
- 2-second sleeps around cancel-flow tests are similarly timing-load-bearing.
10. Slow / flaky areas
- Core suite is the long pole (~5k tests, serial) even post-fix; expect the 3.12 matrix job around 28–31 minutes as of the 2026-06-20 fixes.
- Docker image builds dominate
-m kernel (mitigate by presetting FLOWFILE_KERNEL_IMAGE to skip the ~30s build) and -m docker_integration (builds core+worker+kernel; conftest uses 600s build timeouts).
- MySQL container start can take up to 60s; first-time image pull up to 300s.
- Worker viz tests are tagged
@pytest.mark.slow (flowfile_worker/tests/test_catalog_visualize.py) — not registered as a marker, so it just warns.
- Playwright:
retries: 2 in CI plus trace/video on first retry — this retry budget can mask genuine flakes; workers: 1 avoids port conflicts, not a performance choice.
- A trailing-slash axios/FastAPI mismatch has historically caused silent failures only in Docker (Vite's dev proxy and pytest's
TestClient both mask a 307 redirect that Docker's real network path doesn't) — if a route "works locally but not in Docker," check for a slash mismatch in core logs, not test logic.
Provenance and maintenance
Volatile facts below need periodic re-verification — commands are copy-pasteable.
