Items tagged testing in Feb, 2024
Filters: Year: 2024 × Month: Feb × testing × Sorted by date
Testcontainers (via) Not sure how I missed this: Testcontainers is a family of testing libraries (for Python, Go, JavaScript, Ruby, Rust and a bunch more) that make it trivial to spin up a service such as PostgreSQL or Redis in a container for the duration of your tests and then spin it back down again.
The Python example code is delightful:
redis = DockerContainer(“redis:5.0.3-alpine”).with_exposed_ports(6379)
redis.start()
wait_for_logs(redis, “Ready to accept connections”)
I much prefer integration-style tests over unit tests, and I like to make sure any of my projects that depend on PostgreSQL or similar can run their tests against a real running instance. I’ve invested heavily in spinning up Varnish or Elasticsearch ephemeral instances in the past—Testcontainers look like they could save me a lot of time.
The open source project started in 2015, span off a company called AtomicJar in 2021 and was acquired by Docker in December 2023. # 28th February 2024, 2:41 am
Before we even started writing the database, we first wrote a fully-deterministic event-based network simulation that our database could plug into. This system let us simulate an entire cluster of interacting database processes, all within a single-threaded, single-process application, and all driven by the same random number generator. We could run this virtual cluster, inject network faults, kill machines, simulate whatever crazy behavior we wanted, and see how it reacted. Best of all, if one particular simulation run found a bug in our application logic, we could run it over and over again with the same random seed, and the exact same series of events would happen in the exact same order. That meant that even for the weirdest and rarest bugs, we got infinity “tries” at figuring it out, and could add logging, or do whatever else we needed to do to track it down.
[...] At FoundationDB, once we hit the point of having ~zero bugs and confidence that any new ones would be found immediately, we entered into this blessed condition and we flew.
[...] We had built this sophisticated testing system to make our database more solid, but to our shock that wasn’t the biggest effect it had. The biggest effect was that it gave our tiny engineering team the productivity of a team 50x its size.
— Will Wilson, on FoundationDB # 13th February 2024, 5:20 pm