Testcontainers have forever changed the way I write tests 

Whenever you upload a video I am always impressed by just how advanced tools around programming have become. This is stark contrast with the legacy stuff I deal with daily.

Small correction: At 5:20 you should use the "require" package instead of "assert". This is because you don't want to the test to continue running in this case. "require" will cause the test to immediately exit, whereas "assert" will just mark the test as failed, but continue executing the rest of the test, which might give you strange failure messages. Likewise at 6:59

If you are sponsored by docker, it would be cool to see more videos about using docker for testing and integration. I would especially like a video (or few) about how do you start a project from ”scratch”? You have a great ability to pick out the important bits and show only those in a clear manner. So while documentation and plenty of learning material exists, I think you really could add a valuable learning resource by doing a video in your style, from even more basic point of view. I’d encourage pitching the idea to Docker. Golang seems like a great language for this kind of content as tests are so integral for it. And the syntax is very easy. This would allow showcasing all of the code in the same video, which I feel would be essential for the consept. I’d love to see you answer simple questions through your usual straight-forward demonstrations, on an ”empty” project: How do you add and update dependencies with docker? How do you write the very first tests in test-driven project, and how do you expand from that? And lastly how do you go from a development image to a deployable, minimal image?

I love how informative, concise and useful these videos are. Thanks for your work!

Instead of spinning up multiple test containers I just stick with one and make sure that I have setup and tear down code to keep the database state consistent across all tests. Spinning up multiple containers in parallel would put a lot of load on my CI/CD environment, so unless the tests are painfully slow I would just stick with sequential test runs.

Awsome! Thanks for linking that Git repos too!

idk abt this one. the last thing im about to do after i finish writing poorly design barely functioning code is test it. im sure u guys agree with me on this one

Excellent explanation and useful examples, thank you!

This is fire! Thanks for sharing. I can now do all of my personal development without deploying.

really cool project, i always hate the boiler plate around setting up docker-compose tests, tearing stuff down properly, implementing health checks. this will make things much easier in future

I like to live dangerously and mock it all (if I had my way - alas, my team also chose test-containers, now I test 10x as slow)

Thanks for sharing, I'll consider using testingcontainers in the future

Watched this video and started to use testcontainers immediately in our CICD system. Really cool!

Apart from the videos being extremely informative, I am amazed by how well the video is edited and put together? what software are you using to edit this amazing videos if I may ask

Years ago I made some some functions to automatically control docker from tests. It was cool but not all too great. I need to have a look at this Testcontainers stuff (actually have the tab open for some time, just havent had the time). Thanks!

Fantastic advise! A friend in HR whom I respect greatly says that most problems have a large people component, it's never about only tech

That's very handy. Thanks for the explanation!

Awesome video, thanks for sharing !

Geat video, maybe its time to get into tests :) Dragonfly would also be something you could take a look at instead of valkey

One thing I find docker compose is good at is documenting what your environmental dependency in one place. It is good when you have to jump between many projects. I personally never faced with the issue of port binding usually because my tests run from another “test” container. All in all I agree there are merits to using the package there is also added complexity when orchestrated from another container by requiring to share a socket with the host

Fun fact - can't be used with podman because test-container's implementation of DockerCompose relies on "compose ps --format=json" and it's still not implemented in podman. And nobody cares, unfortunately.

Will look into this, part of my problem is having x number of containers to start locally and manage that. Never liked mocking away a lot of things as your left with a lot of assumptions so this should help with that. At the very least should be good for CI/CD testing before it hits a testing/prod enviornemnt.

Great video, thanks

Nice video, So one note for tests, in the modules section you talked about parallel tests and stuff, but one thing, tests should be written independently, it should behave independent, it should make no problem for other tests, so you tests should be deterministic.

Glad to see valkey getting so much love ❤

There is more value in this video than i handle!

If you don't want to pay the performance price for starting containers, try this approach: Add a test package to each service that you need. This test package contains all the test data that the service uses to determine that it works correctly (plus setup code, etc). Add a test dependency in your project to this test package and then use the test data to test your own code. If the service isn't under your control, you can write a small project which sends test requests to the service and verifies the responses. The requests and responses are then your test package which your project can consume. Every once in a while, you need to rerun this "collect test data" project but your tests will be several orders of magnitude faster.

You can technically avoid the port conflict by not allocating port at all and using docker inspect to find the container ip (they all have one and the wiki page of docker inspect shows how to get it in an example). But having wrappers around popular services and automatic clean up does put test container apart.

Thanks for the video. The wait forlog is the next flakey part.

I'm curious how heavy the added overhead of spinning up so many container instances (esp. multiple database instances) can be considering some code bases have thousands of tests to be run + how much delay it introduces

My team lead was amazed when I've made a deployment pipeline which applies all migrations with dbup, lol.. I'm a new guy with like a year of experience (THEY DO ALL THE DEPLOYMENT MANUALLY)

another solid video. nice one.

what plugin are you using for that column line? love ot

Those wait parameters to postgres preconfigured container should really be included in the module though. One issue with it is for example spinning up Kafka on each test run, takes much more time than hosting it in docker manually

So you’ve covered test containers, now it’s time for dev containers!

This is great to run locally, unfortunately this is not usable when running inside a docker container run within a CI. I have yet to see some library that would integrate with both environments (use mysql container spawned by CI, but spawn a local container when ran locally)

I came for the cool tech, I stayed for the digs at redis

I unfortunately can't use testcontainers at my job because it requires you to be able to run docker-in-docker to run in the ci pipeline which is apparently considered a security risk and therefore not allowed FeelsBadMan

this is awesome!

Can you please make one on Delve how to setup it and start debugging using it pleaase.

How are these videos made? With the text and animations? Without a giant motion graphics budget?

May I ask what font you are using for coding?

That's pretty cool! And wow you type fast!

you have a link to your dotfiles?

Testcontainer modules should really offer more random passwords by default

0:38 Are we to assume the starting state of the accumulator is +/- infinity, int_min/max, or zero? If we're saying flakiness is a negative value when all is said and done, are we trying to get that number closer to zero? That's my assumption because there's no way that we can have a positive end result, meaning there's less flakiness than anti-flakiness (no idea what that means here). I get that it's supposed to be shorthand for a codey joke, but reduce in this notation means that you flatten a container into a singular dimension, which could mean either reducing a list of events with an initial state (acc) into a final state structure or flatten an N dimension container into a single value/N-1 dimension container.

Great video However, 11:15 do not use testcontainers for development (there's devcontainers for that)

But what if the container stops right after it shows the log message? I'm having this problem in a small application and I can't find any function that checks the health of the container even after it stared... :(

Everyone has a test environment, some people have a seperate prod environment. :)

I wrote my own testcontainers implementation a few years ago in a couple of hours. It was just a few hundreds lines of code.

These seem great as part of a cicd pipeline, not in the dev workflow. I experienced a lot of headaches waiting for containers to start just trying to run locally.

Seems great for specific uses cases where you have to replicate complex external services like AWS, but for something like postgresql there is a lot of boilerplate code for every single test. My current project runs 350 tests, imagine having to setup a postgresql test container for each of them

too bad it doesn't work with podman

I don't want my docker containers to be "Typed"

Was hoping he showed how to run firefox in docker

Can't wait for this awesome project to get locked behind licensing fees 😬 Honestly, I'm getting kinda jaded with these "it's free... and now it's not!" rug-pulls. Of course there needs to be a way to support FOSS projects, but that approach can't be it...

there I am, first of em all

Honestly, a docker compose file is easier than this. If you aren’t cleaning up after your tests, that’s on you.

second also hoi DoC

first

First you tell us you dont have redis running, then you cant start your redis container because you do have it running. What gives?

Seems like a waste of energy and time when u can just mock 😂

Where can i find your theme and font? Im sure i probably already have it somewhere and have just lost it?

I love to test in prod coz I develop medical robots and nuclear missile guidance systems

Very cool, thanks for sharing!