codeguard-ruby

Ruby Codeguard Gate

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

30-Second Start

1. At the repository root, confirm Gemfile or that the target file exists.
2. Probe tools:rubocop --version。
3. First do a read-only check:rubocop。
4. Classify results as: code violations, missing configuration, missing tools, tool internal errors.
5. Only perform for safely fixable items:rubocop -A。
6. Rerun lint, and run the project's existing test/build gates.

Can be directly requested:

• "Check this Ruby project, do not modify it first, and give me a classification of lint failures."
• "Only fix Ruby formatting issues; list semantic issues first."
• "Verify Ruby lint, test, and build evidence before committing."

Capability Boundaries

✅ Good At Handling

1. Identify Ruby workspaces based on .rb and project markers.
2. Run rubocop and retain exit codes, scope, and tool versions.
3. Distinguish formatting, static rule, configuration, dependency, and environment failures.
4. Use rubocop -A to handle reversible issues and rescan.
5. Report local results layered with CI/build/test evidence.

⚠️ 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.
3. If the project has custom configuration, the committed configuration prevails.
4. Whether generated code, vendor, and cache directories are scanned must follow repository rules.

❌ Not Applicable

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

When to Use

• The user requests checking or fixing Ruby code standards.
• AI modified .rb, requiring pre-commit verification.
• CI shows failures related to rubocop .
• Need to determine whether an issue can be automatically fixed or must be handled manually.

When Not to Use

• The main task is learning language syntax, framework design, or business modeling; use the corresponding language professional skill instead.
• The main task is dependency vulnerabilities, security audit, or license governance; use a specialized security skill.
• When the user only asks to explain one error and there is no project context, first provide a local explanation 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, inspect the diff first; destructive or large-scale changes must be explicitly confirmed by the user.

Execution Contract

Project	Current facts
Status	stable(since Codeguard V0.2)
File extension	.rb
Project marker	Gemfile
Integration configuration	Based on the repository's existing configuration
Tool preparation	gem install rubocop
Probe command	使用命令查找与项目配置检查
lint	rubocop
format/fix	rubocop -A
Project-level gate	rubocop

Standard Workflow

Step 1: Determine the real scope

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

Step 2: Read the project contract

Read the actual commands in the repository's existing configuration and CI. Repository configuration takes precedence over the examples in this skill; if the two conflict, report the difference 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: Execute read-only checks

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

Step 5: Failure classification

Type	Typical signal	Handling
Formatting	Indentation, whitespace, import order	Allow formatter, then check the diff
Static rules	unused, complexity, naming, dangerous APIs	Minimal semantic fix; no bulk guessing
Configuration	parser/config/schema not found	Fix integration or report prerequisites
Environment	command not found, version conflict	Report installation/version requirements; do not install silently
Internal tool error	crash, timeout, parser exception	Preserve the original evidence and narrow down the reproduction scope

Step 6: Controlled fixes

Prefer to run rubocop -A. Only handle issues that are certain and reversible; dependency upgrades, rule exemptions, generated files, and business semantic 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. Layered evidence: Report lint, format, compile, test, and security separately.
3. Minimal changes: Do not refactor along the way, and do not expand style fixes into business rewrites.
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

Ruby 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. Missing tools are not a pass — must output UNVERIFIED and a clear preparation method.
2. A formatter is not a linter — all-green formatting cannot cover up static rule 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} must be replaced with real, authorized paths.
5. Auto-fix may enlarge the diff — After fixing, review the diff first, then run the regression gate.
6. Generated and vendor directories require an explicit policy — Do not scan or modify third-party content across the whole repository at will.

Domain pitfalls and fixes

1. Project configuration takes precedence — Tool defaults must not override rules and version constraints already committed in the repository.

When information is insufficient

Do not just say "please provide more information". First give 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 auto-fix is 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. Exemption is allowed only when the user explicitly accepts it and the reason 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; for each batch, rerun the original command and review the diff.

Q6: If it passes locally, can we say CI will pass? No. It is also necessary to align with CI's versions, 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 this language's 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 them all at once.