Go test: What happens under the hood with the testing harness when you run it (matttproud.com)

If you’re like most Go developers, you probably haven’t given much thought to what happens when you run go test in a project. You just take for granted that it works and your tests run (irrespective of whether they pass or not — though hopefully passing). But it turns out that a lot of things happen in the time between invoking go test and a single line of your tests start running. Let’s dive in and see how go test works.