# reviewdog — Turn Lint Into PR Review Comments

> reviewdog reads any linter output and posts precise PR comments or Checks, so teams can enforce quality without noisy, copy-pasted logs in reviews.

## Install

Copy the content below into your project:

## Quick Use

1. Install (Homebrew or Go):
   ```bash
   brew install reviewdog/tap/reviewdog
   # or
   go install github.com/reviewdog/reviewdog/cmd/reviewdog@latest
   ```
2. Local smoke test (no PR needed):
   ```bash
   echo "README.md:1:1: demo message" | reviewdog -f=golint -reporter=local
   ```
3. In CI, report to GitHub PR review:
   ```bash
   # Needs GITHUB_TOKEN + a PR context
   reviewdog -f=golint -reporter=github-pr-review -filter-mode=diff_context
   ```

## Intro

reviewdog reads any linter output and posts precise PR comments or Checks, so teams can enforce quality without noisy, copy-pasted logs in reviews.

- **Best for:** repos that have multiple linters and want consistent, diff-scoped PR feedback
- **Works with:** GitHub/GitLab CI, any linter output (checkstyle/eslint/golangci-lint, etc.)
- **Setup time:** 10–20 minutes

## Practical Notes

- Quant gate: make CI fail when new issues appear (diff-only mode).
- Tip: start with `-reporter=local` before wiring PR credentials.

## Pattern: “diff-only” quality gate

When a repo has a backlog of existing issues, the fastest rollout is **only comment on new problems introduced by the PR**.

1) Pick one linter and ensure it prints file/line/col.

2) Pipe to reviewdog with diff filtering:

```bash
<your_linter_cmd> | reviewdog -f=golint -reporter=github-pr-review -filter-mode=diff_context
```

3) Tighten gradually:
- Start as `github-pr-review` (developer-friendly),
- then switch to `github-check` (status checks) if you want a strict merge gate.

## Pattern: unify many linters into one “review surface”

If your CI runs multiple tools (format, security, deps, etc.), keep the PR readable:
- Use a consistent reporter (Checks or Review),
- use consistent severity mapping,
- keep messages short and actionable (first sentence: what to change).

## Troubleshooting

- If nothing posts: validate you’re running in a PR context and tokens are present.
- If comments are too noisy: use diff filtering, or limit to changed paths only.

### FAQ

**Q: Do I have to use GitHub Actions?**
A: No. reviewdog can run in many CI systems; the key is having a PR diff context when you want PR comments.

**Q: Can I run it locally?**
A: Yes. Use `-reporter=local` to validate parsing and formatting before wiring CI credentials.

**Q: How do I avoid commenting on old issues?**
A: Use diff filtering (`-filter-mode=diff_context`) so only new issues are surfaced.

## Source & Thanks

> Source: https://github.com/reviewdog/reviewdog
> License: MIT
> GitHub stars: 9,286 · forks: 485

---

<!-- ZH -->

## 快速使用

1. 安装（Homebrew 或 Go）：
   ```bash
   brew install reviewdog/tap/reviewdog
   # 或
   go install github.com/reviewdog/reviewdog/cmd/reviewdog@latest
   ```
2. 本地先跑通（不依赖 PR）：
   ```bash
   echo "README.md:1:1: demo message" | reviewdog -f=golint -reporter=local
   ```
3. 在 CI 里发到 GitHub PR Review：
   ```bash
   # 需要 GITHUB_TOKEN 且在 PR 上下文中运行
   reviewdog -f=golint -reporter=github-pr-review -filter-mode=diff_context
   ```

## 简介

reviewdog 可以读取任意 Lint/静态分析输出，并把问题精确贴到 PR diff 上（Review 评论或 Checks）；让质量门槛自动化落地，不再靠复制粘贴日志，并方便多仓库统一规则。

- **适合谁：** 同时跑多个 linter、希望把反馈“只对本次改动生效”的代码仓库
- **可搭配：** GitHub/GitLab CI；支持多种 linter 输出格式（checkstyle/eslint/golangci-lint 等）
- **准备时间：** 10–20 分钟

## 实战建议

- 量化门槛：只对本次 diff 新增问题失败（diff-only 反馈）。
- 建议：先用 `-reporter=local` 跑通，再接入 PR 权限与 Token。

## 常用打法：先做“只看 diff 新增问题”

当仓库历史遗留问题很多时，最快的上线方式是：**只对 PR 引入的新问题发评论**，避免“一上来就刷屏”。

1）先选一个 linter，确保输出里有 file/line/col。

2）用 reviewdog 做 diff 过滤：

```bash
<你的_linter_命令> | reviewdog -f=golint -reporter=github-pr-review -filter-mode=diff_context
```

3）逐步收紧：
- 先用 `github-pr-review`（体验更友好），
- 需要强制合并门槛时再切到 `github-check`（更像 gate）。

## 常用打法：把多个 linter 统一到一个“review 面板”

CI 同时跑格式化、安全、依赖等工具时，关键是让 PR 结果可读：
- reporter 统一（Checks 或 Review 选一个），
- 严重级别映射统一，
- 每条消息第一句话直接告诉“改什么”。

## 排错建议

- 完全没输出：先确认确实在 PR 上下文中跑，并且 token/权限齐全。
- 太吵：启用 diff 过滤，或按路径白名单/黑名单收敛。

### FAQ

**一定要 GitHub Actions 吗？**
答：不一定。reviewdog 支持多种 CI；想发 PR 评论时关键是要拿到 PR diff 上下文。

**可以本地跑吗？**
答：可以。先用 `-reporter=local` 验证解析与输出格式，再接入 CI。

**如何避免把历史问题全刷出来？**
答：用 diff 过滤（`-filter-mode=diff_context`），只对本次改动新增问题提示。

## 来源与感谢

> Source: https://github.com/reviewdog/reviewdog
> License: MIT
> GitHub stars: 9,286 · forks: 485


---
Source: https://tokrepo.com/en/workflows/reviewdog-turn-lint-into-pr-review-comments
Author: Script Depot