# AI agent said done but tests fail: make it prove it

> Source: <https://dev.to/shashwat14m/ai-agent-said-done-but-tests-fail-make-it-prove-it-5fo9>
> Published: 2026-11-15 09:11:27+00:00

*I wrote this with help from an AI assistant and checked the steps against the provider docs myself. Originally published at [shipsnag.com](https://shipsnag.com/errors/ai-agent-said-done-tests-fail.html).*

What it looks like:

``` bash
Agent: Done! The feature is implemented and all tests pass.

$ npm test
Tests:       2 failed, 41 passed, 43 total
```

**Short answer:**

Agents often say "done" without running every check, or after quietly changing a test. Run the full test, build, typecheck and lint yourself, read the diff for weakened tests, and make the agent show real output before it finishes.

An agent's "done" is a summary, not a result. Common gaps: it ran only the tests near its change, it never ran the production build or the typechecker, it made a failing test pass by loosening it (an added `.skip` or `.only`, a deleted assertion, an updated snapshot), it left a stub, or it edited files outside the task.

`npm test`, `npm run build`, `npx tsc --noEmit` and `npm run lint`.` git diff --stat` shows which files changed. Check test files for `.only`, `.skip`, removed assertions or rewritten snapshots, and look for `any` casts, `@ts-ignore` and TODO stubs.`CLAUDE.md` or `AGENTS.md`: "Before saying done, run npm test and npm run build, and paste the last lines of each output."`.claude/settings.json`:

```
   {
     "hooks": {
       "Stop": [
         { "hooks": [ { "type": "command",
           "command": "${CLAUDE_PROJECT_DIR}/.claude/hooks/require-tests.sh" } ] }
       ]
     }
   }
bash
   #!/bin/sh
   # .claude/hooks/require-tests.sh
   if ! npm test --silent >/tmp/stop-hook-tests.log 2>&1; then
     echo "Tests are failing. Fix them before you finish:" >&2
     tail -n 30 /tmp/stop-hook-tests.log >&2
     exit 2
   fi
   exit 0
```

Claude Code passes `stop_hook_active` to the hook and stops after 8 blocks in a row, so a test that can never pass won't loop forever.

I build [ShipSnag](https://shipsnag.com), skills for AI coding agents that catch these problems before they ship. The one for this problem is [Prove It Works (free)](https://shipsnag.com/skills/prove-it-works.html).