Files
buzz/crates/buzz-db/TESTING.md
Luke Tornquist bd73490418 ci: run PostgreSQL tests in isolated lane (#6730)
## Why

PR #6660 introduced four PostgreSQL-backed persistence tests and a
focused CI selector, but an exact test-name list does not automatically
cover future database tests. Broad ignored-test execution also exposed
shared-schema races and ambiguity between desired-state and
migration-applied schema expectations.

## What

- Establish a discoverable convention: PostgreSQL unit modules use
`postgres_tests`, PostgreSQL integration binaries use a `postgres_`
prefix, and unrelated external-infrastructure tests use an
`external_infra_` prefix.
- Add a dedicated nextest PostgreSQL profile and archive-backed CI job
covering the relevant crates without enumerating test names.
- Create a run-scoped desired-state source database and a unique
PostgreSQL database per test process for parallel-safe isolation, with
cleanup on success, failure, or interruption.
- Route destructive migration and migration-parity tests to clean
`template0` databases while desired-state tests clone the desired-state
database.
- Document discovery, schema modes, required role privileges, and a
bounded portable local runner.
- Keep the existing infrastructure-free unit-test jobs unchanged.

This is intentionally limited to test and CI harness behavior. It does
not move production database code, change persistence semantics, or
implement issue #20's broader shared test-utility refactor.

## Risk

Low production risk because all changes are confined to tests, CI
configuration, documentation, and test harness scripts.

Remaining operational risks:

- Cleanup retries `dropdb --force` five times across roughly four
seconds. Exhaustion warns with the database name but deliberately does
not mask the test result; individual PostgreSQL diagnostics are
suppressed.
- The seven-package boundary is duplicated between the runner and CI
archive and must remain synchronized if PostgreSQL tests move to a new
crate.
- Portable SHA fallback branches were exercised on Linux; no macOS Blox
workstation was needed for this Linux CI artifact.
- GitHub's unchanged generic Unit Tests job currently fails while
cold-linking `buzz-voice` because `sherpa-onnx-c-api` is absent. The
branch changes no voice/build/toolchain inputs; the exact parent
previously passed that job, and Blox passes the same infrastructure-free
suite (1,450/1,450). A prior-head one-job retry and the final-head run
both reproduced the hosted-runner failure.

## Verification

Author Blox workstation `2020088`:

- `cargo fmt --all -- --check`
- `just clippy`
- `just test-unit`: 1,450 passed; PostgreSQL tests remain skipped in
fast jobs
- PR #6660 focused tests: 4/4 passed through the final runner
- Full lane: 282/282 passed in 10.087s with a non-superuser role limited
to `CREATEDB`, `CREATEROLE`, and `pg_read_all_stats`
  - 272 desired-state tests
  - 10 migration-applied tests
  - 6 explicitly filtered external-infrastructure tests
- Cleanup fault injection: a deliberately underprivileged 282-test run
produced the expected 277 passes and 5 failures, and the post-run
catalog audit found zero lane databases after retry cleanup. The
restored successful run also left zero lane databases.

GitHub exact final head `92c231e48f299ea2af23817763f5ae80ac013d68`:

- [PostgreSQL
Tests](https://github.com/block/buzz/actions/runs/32789030203/job/97630827823):
282/282 passed across 10 binaries in 98.886s; 1,240 skipped, including 6
via the profile filter
- The shared relay/PostgreSQL archive predecessor completed successfully
- [Unit
Tests](https://github.com/block/buzz/actions/runs/32789030203/job/97626930420):
unrelated `sherpa-onnx-c-api` native-link failure described above
- Independent exact-head review on separate Blox workstation `2022762`:
no substantive findings after all initial findings were addressed. The
reviewer independently verified cleanup retry behavior, exit-status
preservation, shell portability, syntax, and a clean exact-head
worktree.

## References

- Stacked on #6660 at exact head
`561de54be4d9c2b622b7c2aa5b61bc3068f47e2a`
- https://github.com/TheSentinel454/buzz/issues/20
-
https://github.com/TheSentinel454/buzz/issues/20#issuecomment-5398526792

Generated with Codex.

## Update — August 24, 2026 review follow-up

- Centralized the repeated PostgreSQL test URL resolution in
crate-local, test-only helpers without introducing the broader shared
utility refactor from issue #20.
- Restored descriptive hybrid/Redis test function names. Structural
`external_infra_*_tests` modules now own exclusion, and the nextest
filter only recognizes module path segments.
- Added a three-second source guard that scans every Rust file and fails
CI when an ignored PostgreSQL test would be omitted or an
external-infrastructure test would be included. Fixture tests cover
accepted modules/binaries and both failure modes.
- Removed the two implementation-plan documents.

Performance profiling on Blox workstation `2027352` (same prebuilt
archive and cargo-nextest 0.9.143 for every comparison):

- Current per-test database model, 8 workers: 10.15–10.40s across three
runs. The 283 `createdb` calls and 284 `dropdb` calls consumed
28.85–29.46 aggregate seconds, about 39–40% of aggregate test-process
duration.
- Reusing one database per worker without cleanup: 6.55–6.84s, about 35%
faster, but all three runs failed because global matcher-queue tests
inherited a quiesced community from an earlier test; the failing test
varied with scheduling.
- Reusing workers with `TRUNCATE … RESTART IDENTITY CASCADE`: all 282
tests passed, but total time regressed to 10.47–10.67s. The 265 truncate
calls consumed 24.34–25.45 aggregate seconds, so truncation merely
replaced most clone/drop cost.
- Raising concurrency to 16 workers reduced one isolated-database run to
8.79s, but 24 workers exposed a cluster-global `pg_stat_activity` race.
The profile remains at the proven-safe 8 workers.

Decision: retain unique per-test databases. Harness cleanup uses `dropdb
--if-exists --force`; it drops the database rather than truncating
tables or deleting rows.

Verification at local branch head
`60086c1f6ee34a193c342255a5e8e6293b60e988`:

- Discovery inventory: exactly 282 intended tests; all 6 hybrid/Redis
tests present and structurally excluded.
- PR #6660 focused persistence tests: 4/4 passed.
- Full PostgreSQL lane: 282/282 passed three times; 1,240 skipped each
run; wall time 9.72–9.96s without profiling shims.
- Non-ignored tests with a desired-state database: 1,234/1,234 passed;
one mesh-demo timeout from the first run passed immediately in
isolation.
- `cargo fmt --all -- --check` and all-target/all-feature clippy for
`buzz-db`, `buzz-deletion`, and `buzz-relay` passed.

Final independent re-review at exact head
`42097c0136ab3fa8f0efe5720ae829c04575b9b6` on separate Blox workstation
`2028455`: no substantive residual findings. The reviewer independently
exercised ordinary strings, zero/one/three-hash raw strings, line/block
comments, and string-contained lookalikes, then reran the full 353-file
scan, shell syntax, Python AST parsing, and diff check.

Independent review found that the source guard's initial regular
expression could miss raw-string ignore reasons and treat a commented
attribute as real. Final head `42097c0136ab3fa8f0efe5720ae829c04575b9b6`
parses valid ordinary/raw Rust string literals only at attributes found
in comment-sanitized source; regression fixtures cover both cases. The
fixture suite, Python compilation, shell syntax, diff check, and full
353-file repository scan pass on Blox.

## Update — August 25, 2026 restack

PR #6660 merged, so this follow-up was rebased from its former exact
parent onto current `origin/main`
(`8d2d0ff5ad42733e9949442c4b6358d0ba87f9a8`). The final candidate head
is `05dcc2ab28948e3ab79bb44839a69f2ba44648a2`; the PR no longer carries
#6660's pre-squash history.

Fresh exact-head verification on Blox workstation `2028572`:

- Discovery guard passed across 353 Rust files; inventory remained
exactly 282 intended PostgreSQL tests.
- PR #6660 focused persistence tests: 4/4 passed.
- Full PostgreSQL lane: 282/282 passed three times; 1,243 skipped each
run; wall time 9.70–9.87s.
- `cargo fmt --all -- --check` and all-target/all-feature clippy for
`buzz-db`, `buzz-deletion`, and `buzz-relay` passed.

## Update — August 25, 2026 final hosted verification

- [GitHub PostgreSQL
Tests](https://github.com/block/buzz/actions/runs/32801679226/job/97667835080):
282/282 passed in 53.787s; 1,243 skipped.
- The final guard scanned all 353 Rust files successfully before the
hosted lane ran.
- The shared relay/archive prerequisite and infrastructure-free Unit
Tests job both passed at exact final head
`42097c0136ab3fa8f0efe5720ae829c04575b9b6`.

---------

Signed-off-by: Luke Tornquist <tornquist@squareup.com>
Signed-off-by: tornquist <tornquist@squareup.com>
2026-09-01 12:07:28 -04:00

3.0 KiB

PostgreSQL-backed tests in buzz-db

The dedicated PostgreSQL CI lane discovers tests and Cargo packages by structure rather than by exact lists. Follow this checklist so a new database test is run automatically and remains safe under parallel execution.

Adding a test

  1. Put the test in a module whose name ends in postgres_tests.
  2. Mark it #[ignore = "requires Postgres"] so infrastructure-free unit-test jobs stay fast.
  3. Connect through crate::test_support::database_url(). The CI wrapper sets this helper's environment to a unique database for each test process; never hard-code the shared development database.
  4. Keep tests that need infrastructure beyond PostgreSQL and Redis in an external_infra*_tests module. The PostgreSQL lane excludes those tests.
  5. Run scripts/test-postgres-test-discovery.sh after adding or moving the test. The same guard runs in CI immediately after changed-path detection.

The wrapper isolates destructive tests by dropping the entire per-test database after the process exits. It does not DELETE rows or TRUNCATE shared tables, so tests may run concurrently without coordinating cleanup.

Choose the schema intentionally

Most tests use the committed desired-state schema from schema/schema.sql. That is the default and is appropriate for data-access behavior.

Tests in migration::postgres_tests receive an empty database and own the embedded migration lifecycle. A test outside that module that intentionally depends on migration-created triggers or seed rows must prefix its function name with migration_schema_; it also receives an empty database with BUZZ_TEST_SCHEMA_MODE=migration.

Helpers that normally run migrations honor BUZZ_TEST_SCHEMA_MODE=desired in the default lane. Do not rerun migrations against a desired-state database. When behavior should match in both schema paths, add explicit desired-state and migration-applied coverage rather than making the bootstrap implicit.

Tests that inspect cluster-wide PostgreSQL state or open least-privilege sessions include cluster_global_ in the function name. Migration-backed cases use migration_schema_cluster_global_. Nextest serializes this small group because separate databases still share pg_stat_activity and roles.

Run the lane locally

Start native PostgreSQL and Redis, activate Hermit, and run:

. ./bin/activate-hermit
scripts/test-postgres-test-discovery.sh
scripts/postgres-test-run.sh

Set BUZZ_POSTGRES_ADMIN_URL to a PostgreSQL maintenance database owned by a role that can create and drop databases. Set PGHOST, PGPORT, PGUSER, and PGPASSWORD for desired-state bootstrap, plus REDIS_URL for Redis-backed tests. The complete privilege-boundary inventory also needs CREATEROLE and membership in pg_read_all_stats, or an ephemeral superuser as CI uses.

The runner creates one desired-state source database per invocation and clones it for ordinary tests. Migration-mode tests start empty. Cleanup retries transient disconnect races before reporting a warning.