codeguard-protobuf

Protobuf Codeguard Gate

Goal: turn "looks fine" into repeatable tool evidence, and honestly distinguish between passed, failed, unverifiable, and planned.

Start in 30 seconds

1. At the repository root, confirm 无专用标记文件 or the target file exists.
2. Probe tools:buf --version。
3. Read-only check first:buf lint。
4. Classify results as: code violations, missing configuration, missing tools, tool internal errors.
5. Only perform safely fixable items:buf format。
6. Re-run lint, and execute the project's existing test/build gates.

You can directly ask:

• "Check this Protobuf project, don't modify anything for now, and give me a classification of the lint failures."
• "Only fix Protobuf formatting issues; list semantic issues first."
• "Verify Protobuf lint, test, and build evidence before committing."

Capability Boundaries

✅ Good at handling

1. Based on .proto and project markers to identify the Protobuf workspace.
2. Execute buf lint and retain exit codes, scope, and tool versions.
3. Distinguish between formatting, static rules, configuration, dependency, and environment failures.
4. Use buf format to handle reversible issues and re-scan.
5. Report local results and CI/build/test evidence in layers.

⚠️ Requires conditions

1. The target tool must be installed and its version compatible with project constraints.
2. Must be executed from the correct repository or module root directory.
3. If the project has custom configuration, the committed configuration takes precedence.
4. Whether generated code, vendor, and cache directories are scanned must follow repository rules.

❌ Not applicable to

1. Do not treat formatter passing as compilation, testing, or security audit passing.
2. Do not silently install tools, upgrade dependencies, or modify team rules.
3. Do not use suppress/ignore/raising thresholds to conceal real issues.
4. Do not claim "checks passed" when tools or configuration are missing.

When to use

• The user requests checking or fixing Protobuf code conventions.
• AI modified .proto, requiring pre-commit verification.
• CI shows failures related to buf lint .
• Need to determine whether an issue can be automatically fixed, or must be handled manually.

When not to use

• If the main task is learning language syntax, framework design, or business modeling, use the corresponding language professional skill instead.
• If the main task is dependency vulnerabilities, security audits, or license governance, use specialized security skills.
• When the user only asks to explain an error and there is no project context, provide a local explanation first and do not claim the repository is all green.

Data and Security

This skill does not collect, upload, send, or store user code and credentials. By default, it only reads local repository configuration and runs local tools; it does not install dependencies over the network, and does not record tokens, passwords, or private source code. Before any automatic fix, check the diff first; destructive or large-scale changes must be explicitly confirmed by the user.

Execution Contract

Item	Current Fact
Status	stable(Since Codeguard V0.3)
File Extension	.proto
Project Marker	No Dedicated Marker File
Integration Configuration	buf.yaml, buf.gen.yaml, buf.work.yaml
Tool Preparation	brew install bufbuild/buf/buf
Probe Command	使用命令查找与项目配置检查
lint	buf lint
format/fix	buf format
Project-Level Gate	buf lint

Standard Workflow

Step 1: Determine the Real Scope

Confirm the repository root, module root, generated directories, vendor directories, and user-specified files. For multi-module projects, first list the modules to be scanned; do not guess based on the current directory.

Step 2: Read the Project Contract

Read buf.yaml, buf.gen.yaml, buf.work.yaml and the actual commands in CI. Repository configuration takes precedence over the examples in this skill; if the two conflict, report the differences first.

Step 3: Probe Tools and Versions

Run 对应工具 --version. Missing tools, incompatible versions, or configurations that cannot be loaded are all recorded as "unable to verify," not as passing.

Step 4: Perform Read-Only Checks

Run buf lint, recording the command, working directory, exit code, tool version, and the first actionable error.

Step 5: Failure Classification

Type	Typical Signal	Handling
Format	Indentation, whitespace, import order	Formatter allowed, then check the diff
Static Rules	unused, complexity, naming, dangerous APIs	Minimal semantic fix; no bulk guessing
Configuration	parser/config/schema not found	Fix the integration or report prerequisites
Environment	command not found, version conflict	Report installation/version requirements; do not install silently
Tool Internal Error	crash, timeout, parser exception	Preserve the original evidence and narrow the reproduction scope

Step 6: Controlled Fixes

Prefer running buf format. Only handle issues that are certain and reversible; dependency upgrades, rule exemptions, generated files, and business semantics changes must be explained separately.

Step 7: Verification Loop

Re-run the same lint command, then run the project's existing tests and build. Write "pass" only when the command, scope, and exit code are all clear; otherwise write "not run" or "unable to verify."

Rules

1. Re-verify with the Same Command: After fixing, you must re-run the original command that triggered the failure.
2. Layer the Evidence: Report lint, format, compile, test, and security separately.
3. Minimal Changes: Do not refactor along the way, and do not expand a style fix into a business rewrite.
4. Configuration First: Do not override the project's existing ignore, dialect, target, or version constraints.
5. No Fabrication: Tools not run, configurations not seen, and platforms not verified must be clearly marked.

Output Template

Protobuf Codeguard 结果
- 范围：<仓库/模块/文件>
- 工具：<名称与版本>
- 命令：<实际命令>
- 状态：PASS / FAIL / UNVERIFIED / PLANNED
- 发现：<按格式/规则/配置/环境分类>
- 修改：<文件与原因；无修改写 none>
- 复验：<命令、退出码>
- 未验证：<测试/构建/平台差异>

Gotchas

1. A missing tool is not a pass — you must output UNVERIFIED and a clear preparation method.
2. A formatter is not a linter — all-green formatting cannot cover static rules or compilation errors.
3. The root directory determines the result — Running in the wrong module may miss issues or load the wrong configuration.
4. Placeholders are not literal arguments — {file} and must be replaced with real, authorized paths.
5. Automatic fixes may expand the diff — after fixing, review the diff first, then run the regression gate.
6. Generated and vendor directories require an explicit policy — do not arbitrarily scan or modify third-party content across the entire repository.

Domain pitfalls and fixes

1. Domain pitfall — After Buf lint passes, you should still check for breaking changes; style compliance does not equal wire compatibility.

When information is insufficient

Do not just say "please provide more information." First provide a safe read-only inspection plan, and list the specific items that still need confirmation:

1. Repository/module root directory;
2. Target tool and version;
3. Project configuration file;
4. Authoritative command in CI;
5. Whether automatic fixes are allowed.

FAQ

Q1: If the tool is not installed, can we conclude the code is fine? No. The status must be UNVERIFIED。

Q2: Can ignore or suppression be added automatically? No. An exemption can only be granted when the user explicitly accepts it and the rationale is recorded.

Q3: Why does it still fail after formatting? The formatter only covers formatting; static rules, configuration, compilation, and tests still need to be handled separately.

Q4: Should generated code be scanned? By default, follow the repository configuration; when there are no rules, exclude generated/vendor first, then explain to the user.

Q5: How can we avoid changing too much at once? First fix in batches by failure category and file, and rerun the original command and review the diff for each batch.

Q6: If it passes locally, can we say CI will pass? No. It is also necessary to align with CI's version, environment variables, operating system, and command scope.

Load resources on demand

• When encountering exit codes, failure classification, or exemption decisions, read references/rules/gate-rules.md。
• When you need to check the language registry, toolchain, and project configuration, read references/tooling/toolchain.md。
• When you need copyable task examples, read by scenario examples/, and there is no need to load all of them at once.