6-week course · Starts May 5

Idiomatic Testing in Go

Stop fighting your tests.

A live, weekly course · Mondays at 1 PM US Eastern / 17:00 UTC

$480 From $360

Save $120 through April 28

See pricing & reserve

Mitchell

Senior Node.js Developer, RIJX.com

Does writing tests feel like a slog?

Do all your tests pass while bugs still ship?
Are you tired of slow and flaky tests?
Does it take longer to write tests than to write the code they test?
Do your tests tend to break every time you make a change?
Does making your code testable seem to make it worse, not better?

Imagine finding joy in writing tests

What if a green test suite actually meant working software?
What if the suite ran fast and never flaked?
What if tests saved you more time than they cost?
What if your tests stayed green when you refactor?
What if testability made your code better, not worse?

AI is not a miracle cure

Coding agents amplify whatever you bring, good or bad. You want to be multiplying good tests, not compounding bad ones, and it takes judgment to tell the difference. Testing skill matters more in the age of AI, not less. This course builds it.

What you'll learn

You'll learn how the Go community actually tests, why its idioms produce clearer, faster, less fragile tests than the patterns most of us bring from other languages, and when breaking those idioms is the right call. By week six, you'll know how to apply all of it to your own codebase.

Week 1

Philosophy and Motivation

Why we test (and what most people miss)
What makes a test good
F.I.R.S.T. in practice
Why the test pyramid is wrong

Week 2

Writing Idiomatic Tests

Why the Go community avoids assertion libraries
Comparing structures with cmp.Diff
The "got before want" convention
Table-driven tests done properly

Week 3

Tools and Techniques

The testing package in depth
Subtests, helpers, and t.Cleanup
Running tests in parallel
go test flags that catch bugs you don't know you have

Week 4

Isolation Strategies, Part 1

Why "mocks" are usually the wrong answer
Using the real thing whenever possible
When fakes beat mocks
An alternative to every mocking framework you've used

Week 5

Isolation Strategies, Part 2

Testcontainers: slow-but-real beats fast-but-fake
Hand-rolled stubs (no code generation needed)
Layering strategies for a typical web app
When to reach for a mocking library anyway

Week 6

The Real World

Rolling this out in your existing codebase
When not to be idiomatic
Live code review of student submissions
Q&A and where to go next

Ready to stop fighting your tests? Reserve your seat — early bird discount ends April 28.

6 free videos

Watch my videos on idiomatic testing

HTTP testing, offline API tests, test flags, and alternatives to mocking

Is this course for you?

You already write Go at work. You’ve written tests. You have a nagging feeling your tests could be better (smaller, faster, clearer, less fragile) but you’re not sure how to get there.

Maybe you came to Go from Java, C#, or Python, and brought testing habits that don’t fit the language. Maybe you’re a team lead who wants to establish a testing style your team can actually maintain. Maybe you’re adopting TDD and want to start with good habits instead of bad ones.

If any of that sounds like you, this course is for you.

When it’s not for you

If you’re brand new to Go, start with my daily newsletter or the Go Tour first. This course assumes you can already read and write Go code.

If you’re deeply committed to testify and aren’t interested in questioning that, this course will frustrate you. The whole point is to show you the Go community’s alternative, and why it tends to produce better tests.

Who are you, anyway?

Hi! I’m Jonathan Hall. I've been programming most of my life, and I've been programming in Go for more than a decade.

In that time, I've written Go for many well-known companies and contributed to many open-source projects, including several you almost certainly use already. I'm the author and maintainer of a popular open-source library written in Go, Kivik, and co-maintainer of GopherJS, the Go-to-JavaScript transpiler. I am also an active contributor on StackOverflow.

I have directly taught and coached dozens of Go developers, and teach thousands through my daily emails and YouTube channel.

Mike Mellenthin

Team Lead, Float Health

How it works

Six live sessions, Mondays at 1:00 PM US Eastern / 17:00 UTC, starting May 5 and running through June 16 (skipping the week of May 25 for Memorial Day). Each session is 90 minutes: presentation, break, then review and Q&A.

Small cohort. Capped at 15 students so every week has room for real discussion and feedback on your code.

Watch replays anytime. Every session is recorded and shared with enrolled students immediately after. Can’t attend live? Catch up whenever you have time. The course is designed to work around your schedule.

24/7 Slack access. Ask questions, share code, and get feedback between sessions, from any timezone and any time of day. I drop in regularly, and fellow students help each other.

Optional homework. Small exercises each week to practice what we covered. No grades, no pressure. Just a nudge to actually do the thing.

Alexander Kaiser

Principal Architect, Textkernel

Pricing

Save $120 on either tier through April 28.

Standard

The full course, with live sessions and ongoing access to the group.

$480 $360

Save $120 through April 28

Reserve your seat

Six live 90-minute sessions
Recordings you can watch anytime
24/7 Slack access with me and fellow students
Code review during sessions
Optional weekly homework exercises

Best value

VIP

Everything in Standard, plus private mentoring after the course.

$800 $680

Save $120 through April 28

Reserve VIP

Everything in Standard, plus:
Two 60-minute 1:1 calls with me in the month after the course
Apply what you learned to your real codebase, one-on-one
Private chat access during the follow-up month
Bundle saves $230 vs. buying the course + Pro mentoring separately

Looking to train a whole team? I also run private cohorts for companies.

Frequently Asked Questions

What's the format?: Six live 90-minute sessions over video call, Mondays at 1:00 PM US Eastern (17:00 UTC). The first half of each session is a presentation and live coding. The second half is review of your code and your questions. Sessions are recorded for students who can't attend live.
Do I need prior experience with Go?: Yes. You should already be able to read and write Go code. This course is not an introduction to the language. If you can write a handler, define a struct, and use a channel, you're ready.
Do I need experience with testing?: Some, but not a lot. If you've written a few TestXxx functions in Go, you have enough background. This course assumes you've done some testing and want to do it better.
What if I can't attend every session live?: Every session is recorded and shared with enrolled students. Live sessions are better (you can ask questions in real time and get code review), but the recordings mean missing one won't derail you.
What's your code review style like?: Constructive and specific. I try to understand what the code was trying to do before I critique how it does it, and I'd rather show you two concrete improvements than lecture in the abstract. Students choose what code to submit for review. If you want to see the style in action, I have a playlist of public code reviews on YouTube.
Do you offer a guarantee?: Yes. If the course isn't for you, just ask for a refund before the second session and I'll happily oblige.
What tools or setup do I need?: A recent version of Go, an editor you're comfortable with, and Git. Nothing fancy. Anything exotic we use, I'll explain and provide.
Will this course cover TDD?: Not as its primary focus. TDD is a workflow; this course is about the tests themselves: how to write ones that are clear, fast, and maintainable. The techniques apply whether you write tests first, after, or somewhere in between.
Can you run this for my team privately?: Yes. If you have 5 or more engineers and want a cohort run privately for your company, scheduled around your team's availability and with examples drawn from your codebase where possible, I offer this as a separate engagement. Email me to discuss.
I have other questions!: Great. Send them to me, and I'll answer.

Ready to stop fighting your tests?

Next cohort starts Monday, May 5. Seats are limited to 15. Early bird discount ends April 28.

See pricing & reserve