> As far as I can tell you can’t step through tests in the debugger
Maybe I am missing something, but that is not correct. You can debug tests the same way as you debug any other code. Even works with the mentioned/used Go extension for VS Code.
I have no idea in VSCode, but with JetBrains Gogland, debugging tests is stupidly easy. Simply add the breakpoint where you want it, left click on the play button in the line of the test declaration, click debug in the contextual menu, and off you go.
In Go test files, there's now a codelens annotation above every Test function with "run test" and "debug test" commands. Just click "debug test" to launch a debugger against that test.
Maybe I am missing something, but that is not correct. You can debug tests the same way as you debug any other code. Even works with the mentioned/used Go extension for VS Code.