# My fix checker found two missing tests. Then it wrote them.

> Source: <https://dev.to/connabyss/my-fix-checker-found-two-missing-tests-then-it-wrote-them-58pd>
> Published: 2026-11-01 03:01:28+00:00

In [my last post](https://dev.to/connabyss/rich-click-and-qs-passed-my-fix-checker-my-checker-didnt-12i2), [Bite](https://github.com/connabyss/bite) checked some well-known projects and found a few small gaps: changes that no test would notice if they broke. Two of them:

`<kbd>Ctrl</kbd>` is drawn in bold yellow, and no test checks it.
Finding a gap is the easy half. Someone still has to write the test. So this week Bite got a new option, `--write-tests`, that tries to write it.

For each change no test noticed, a fresh AI worker writes one small test on a copy of the project. Then Bite doesn't take its word for it. It runs the test itself:

If either part goes wrong, Bite throws the test away and says so. It uses your own Anthropic API key, and `--budget` caps what a run spends.

| Gap | Bite's test | With the change | Without it | Cost | 
|---|---|---|---|---|
| Rich `<kbd>` | prints `<kbd>Ctrl</kbd>` , checks Ctrl is bold yellow | passes, twice | fails: Ctrl not bold yellow | $0.14 | 
| chi XML | sends XML through chi's compressor, checks it comes back gzipped | passes, twice | fails: XML not gzipped | $0.10 | 

Total: $0.34. That's more than the two rows add up to, because of the next part.

**The first chi try got thrown away, and that was Bite's fault.** Go runs tests by folder, not by file, and Bite asked Go to run one file alongside the whole project. Go refused before running anything. Bite's rule caught it: a test that fails before it even runs doesn't count. So it threw the test out instead of showing a fake result. The fix is in [PR #67](https://github.com/connabyss/bite/pull/67), and the second try worked.

Before Bite could do this, Claude had already written a test for each gap the slow way, to confirm the gaps were real. So there was an answer key.

Here's the Rich one, exactly as Bite wrote it:

```
# Guards that <kbd>…</kbd> in Markdown renders its text in the markdown.kbd style.
from rich.console import Console
from rich.markdown import Markdown

def test_kbd_inline_html_is_styled():
    console = Console(
        file=__import__("io").StringIO(),
        force_terminal=True,
        color_system="truecolor",
        width=40,
    )
    console.print(Markdown("Press <kbd>Ctrl</kbd> now"))
    output = console.file.getvalue()
    assert "\x1b[1;93mCtrl\x1b[0m" in output
```

On my own copy of Rich, Bite ran as a GitHub Action on a pull request. It found the `<kbd>` gap, wrote the test, and opened a small pull request with the test in it. I merged that pull request, and Bite's check on the original pull request turned green. Gap found, test written, test merged, without anyone typing a test.

It's in [v0.7.0](https://pypi.org/project/bite-check/) (`pipx upgrade bite-check`). On your own computer: `bite --write-tests`. In GitHub Actions, the setup is in [Bite's README](https://github.com/connabyss/bite#have-bite-write-the-missing-test-opt-in-your-own-key). Since this trial, Bite also asks a second fresh check whether each test is fair before showing it.

*Disclosure: I'm not a coder. Claude ran these trials, wrote Bite's code and helped me draft this post. The numbers come from the run logs.*