Comment by lukehoban

21 days ago

As peer commenters have noted, coding agent can be really good at improving test coverage when needed.

But also as a slightly deeper observation - agentic coding tools really do benefit significantly from good test coverage. Tests are a way to “box in” the agent and allow it to check its work regularly. While they aren’t necessary for these tools to work, they can enable coding agents to accomplish a lot more on your behalf.

(I work on Copilot coding agent)

In my experience they write a lot of pointless tests that technically increase coverage while not actually adding much more value than a good type system/compiler would.

They also have a tendency to suppress errors instead of fixing them, especially when the right thing to do is throw an error on some edge case.