test(testcontainers): add a DB connection-blip harness by d-cs · Pull Request #4862 · triggerdotdev/trigger.dev

d-cs · 2026-09-01T13:00:37Z

Summary

Adds a test-only harness for simulating a Postgres connection blip, so tests can prove their database code survives a dropped connection. It exports createDbBlipController and a postgresBlipTest fixture from @internal/testcontainers.

How it works

The harness severs connections from a separate admin connection using pg_terminate_backend, scoped to the test's own database, so it composes with any Prisma client under test and stays isolated across parallel tests. Two modes:

severIdle() kills idle backends. A pooled (driver-adapter) client absorbs this transparently: the pool evicts the dead connection and the next query just works.
severDuringNextStatement() kills a statement mid-flight, surfacing a connection error to the caller; the client then recovers on the next retry.

The bundled tests demonstrate both, plus the correctness property that matters before adding retries anywhere: a non-idempotent write double-applies when retried after a post-commit blip, while an idempotent write (deterministic id plus ON CONFLICT) stays at exactly one row.

changeset-bot · 2026-09-01T13:00:43Z

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Latest commit: 22b42a5

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coderabbitai · 2026-09-01T13:01:38Z

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Walkthrough

Adds a Postgres blip controller that terminates idle or active database backends. Exports a postgresBlipTest fixture with controller lifecycle management. Adds PostgreSQL adapter dependencies and tests for connection recovery, in-flight statement failures, read retries, and idempotent versus non-idempotent writes after connection termination.

Merge Risk: 🔵 Low · up to 9d00c

This change adds a private test harness that can terminate PostgreSQL sessions to simulate connection failures. The standard fixture is isolated, but the directly exported helper can affect unrelated sessions if given a shared database connection, so the PR is mergeable with owner awareness or follow-up to keep that capability scoped to test-owned databases.

🚥 Pre-merge checks | ✅ 3 | ❌ 2

❌ Failed checks (2 warnings)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The description accurately explains the harness, its isolation model, supported failure modes, and test coverage. However, it omits the required template sections for issue closure, checklist, testing…	Update the description to include the required template sections. Add the issue reference, complete the checklist, document the commands and results used to test the change, provide a short changelog entry, and state whether screenshots are…
Docstring Coverage	⚠️ Warning	Docstring coverage is 42.86% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 7 functions across 2 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the addition of a testcontainers database connection-blip harness and follows the repository convention.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Description check

Explanation

The description accurately explains the harness, its isolation model, supported failure modes, and test coverage. However, it omits the required template sections for issue closure, checklist, testing steps, changelog, and screenshots.

Resolution

Update the description to include the required template sections. Add the issue reference, complete the checklist, document the commands and results used to test the change, provide a short changelog entry, and state whether screenshots are applicable.

✨ Finishing Touches 💡 1

📝 Generate docstrings 💡

Create stacked PR
Commit on current branch

🧪 Generate unit tests (beta)

Create PR with unit tests
Commit unit tests in branch tri-13551-db-blip-test-harness

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pkg-pr-new · 2026-09-01T13:57:32Z

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commit: 22b42a5

…ests Adds DbBlipController + a postgresBlipTest fixture that sever a test Postgres connection via pg_terminate_backend, so a vertical can prove its DB code survives a disconnect without a proxy or extra container. Includes tests that exercise the harness: a severed read fails, an in-flight statement is terminated mid-flight, a non-idempotent write double-applies on retry while the idempotent form does not, and a pg-driver-adapter client recovers a model read through a blip. TRI-13551

devin-ai-integration

Devin Review found 1 new potential issue.

devin-ai-integration · 2026-09-02T11:09:38Z

+          AND pid <> pg_backend_pid()
+          AND backend_type = 'client backend'
+          AND state = 'idle'`


🔍 Multiple controllers can sever each other

When two controllers share one database, severIdle can terminate the other controller's idle admin connection. Direct users then lose one harness unexpectedly.

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d-cs self-assigned this Sep 1, 2026