testfix

AI-powered CLI that automatically fixes failing tests — non-interactive, pipeable, CI-ready.

# Tests failing? Just run testfix.
$ testfix pytest

──────────────────────── Attempt 1/5 ────────────────────────
🔴 2 failing, 8 passing (attempt 1)
   └─ test_login  tests/test_auth.py:10
   └─ test_register  tests/test_auth.py:25

🤖 Asking claude to fix 2 failure(s)…
Generated 1 file fix(es)

─── src/auth.py ──────────────────────────────────────────────
--- a/src/auth.py
+++ b/src/auth.py
@@ -3,7 +3,7 @@
 def login(user, password):
-    return db.find(user) is not None        # BUG: doesn't check password
+    return db.find(user, password) is not None

  ✔ Applied fix to auth.py (backup: .testfix.bak)

──────────────────────── Attempt 2/5 ────────────────────────
✅ All tests pass! (attempt 2)

Why testfix?

Every developer faces the same loop: run tests → fix code → run tests → ...

Tools like aider are powerful but require an interactive session. testfix is different:

Install

pip install testfix

Requires Python 3.9+ and one of: Anthropic API key, OpenAI API key, or ollama running locally.

Usage

# Basic: run pytest, fix failures, retry up to 5 times
testfix pytest

# Specific test file
testfix pytest tests/test_auth.py

# Max iterations
testfix --max-tries 3 pytest

# Fix once and re-run (equivalent to --max-tries 2)
testfix --once pytest

# Preview fixes as diffs WITHOUT applying
testfix --dry-run pytest

# Use OpenAI instead of Claude
testfix --provider openai pytest

# Use local ollama (free, no API key needed)
testfix --provider ollama pytest

# Use a stronger model for hard bugs
testfix --provider openai --model gpt-4o pytest

# Focus fixes on a specific source file
testfix --file src/auth.py pytest

# Works with any test runner
testfix npm test
testfix go test ./...
testfix cargo test
testfix vitest

Supported Test Frameworks

Pre-push hook

Automatically fix failing tests before every push:

# .git/hooks/pre-push
#!/bin/sh
testfix --once --provider ollama pytest

LLM Providers

# Claude (default) — best quality
export ANTHROPIC_API_KEY=sk-ant-...
testfix pytest

# OpenAI
export OPENAI_API_KEY=sk-...
testfix --provider openai pytest

# Local ollama (free, private, no API key)
# Install: https://ollama.ai then: ollama pull qwen2.5:7b
testfix --provider ollama pytest

How it works

1. Run your test command and capture output
2. Parse failures: test names, file paths, tracebacks
3. Find the source files that need fixing (not the test files)
4. Ask AI to fix the source code based on the failure context
5. Apply patches (with .testfix.bak backups)
6. Repeat until all tests pass or max tries reached

CI usage

# GitHub Actions
- name: Fix and test
  run: |
    pip install testfix
    testfix --provider openai --max-tries 3 pytest
  env:
    OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}

Full developer workflow

Combine with the rest of the ecosystem for end-to-end AI-assisted development:

# 1. Morning standup
standup-ai --yesterday

# 2. Review your code before committing
critiq --staged

# 3. Fix failing tests automatically
testfix pytest

# 4. Generate commit message
gpr --commit

# 5. Generate PR description
gpr

# 6. Pack context for AI code review
gitbrief --changed-only

# 7. Generate changelog on release
changelog-ai --since v1.0.0

Install the full suite:

pip install standup-ai critiq testfix gpr gitbrief changelog-ai

Related tools

• critiq — AI code reviewer (catches issues before they become failing tests)
• difftests — AI test generator (generates tests for your diffs)
• gpr — AI PR description generator
• gitbrief — AI context packer for LLMs
• standup-ai — AI daily standup generator
• changelog-ai — AI changelog generator
• prcat — AI PR reviewer for teammate PRs

License

Business Source License 1.1 — free for individuals and non-commercial use. Commercial use requires a license after the Change Date (2028-01-01), at which point this project converts to Apache 2.0.