codeguard-zig

Zig Codeguard Gate

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

Start in 30 Seconds

1. At the repository root, confirm build.zig or the target file exists.
2. Probe tools:zig version。
3. Read-only check first:zig fmt --check .。
4. Classify results as: code violations, missing configuration, missing tools, tool internal errors.
5. Only perform safe-to-fix items:zig fmt。
6. Re-run lint, and execute the project's existing test/build gates.

Can be requested directly:

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

Capability Boundaries

✅ Good At Handling

1. Based on .zig and project markers to identify Zig workspaces.
2. Execute zig fmt --check . and retain exit codes, scope, and tool versions.
3. Distinguish formatting, static rules, configuration, dependency, and environment-related failures.
4. Use zig fmt 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 mask real problems.
4. Do not claim "checks passed" when tools or configuration are missing.

When to Use

• The user requests checking or fixing Zig code standards.
• AI modified .zig, and pre-commit verification is needed.
• CI has failures related to zig fmt --check . .
• Need to determine whether a problem can be fixed automatically or must be handled manually.

When Not to Use

• When the main task is learning language syntax, framework design, or business modeling, use the corresponding language professional skill instead.
• When the main task is dependency vulnerabilities, security auditing, or license governance, use specialized security skills.
• When the user only asks to explain a single 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 modifications must be explicitly confirmed by the user.

Execution Contract

Item	Current fact
Status	stable(since Codeguard V0.5)
File extension	.zig
Project marker	build.zig
Integration configuration	The repository's existing configuration prevails
Tool preparation	Built into the Zig toolchain
Detection command	zig version
lint	zig fmt --check .
format/fix	zig fmt
Project-level gate	zig fmt --check .

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, first list the modules that will be scanned; do not guess based on the current directory.

Step 2: Read the project contract

Read the repository's existing configuration as authoritative and the actual commands in CI. The repository configuration takes precedence over the examples in this skill; if the two conflict, report the difference first.

Step 3: Detect tools and versions

Run zig version. A missing tool, an incompatible version, or an inability to load configuration is all recorded as "unable to verify", not as a pass.

Step 4: Perform read-only checks

Run zig fmt --check ., and record 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	The formatter is allowed, followed by checking the diff
Static rules	unused, complexity, naming, dangerous APIs	Minimal semantic fixes; no bulk guessing
Configuration	parser/config/schema not found	Fix the integration or report the prerequisites
Environment	command not found, version conflict	Report installation/version requirements; do not install silently
Tool internal error	crash, timeout, parser exception	Preserve the raw evidence and narrow the reproduction scope

Step 6: Controlled fixes

Run zig fmtfirst. 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. Only write "pass" 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, the original command that triggered the failure must be re-run.
2. Layered evidence: lint, format, compile, test, and security are reported 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

Zig 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 override static rules or compilation errors.
3. 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. 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 whole repository.

Domain pitfalls and fixes

1. Domain pitfalls — zig fmt --check only validates format; it must be combined with the build/test results for the target Zig version.

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 tools and versions;
3. project configuration files;
4. authoritative commands 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. 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; if there are no rules, exclude generated/vendor first, then explain to the user.

Q5: How can we avoid making too many changes at once? First fix in batches by failure category and file, rerunning the original command and reviewing the diff for each batch.

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

Load resources on demand

• When encountering exit codes, failure categories, or exemption decisions, read references/rules/gate-rules.md。
• When it is necessary to verify this language's registry, toolchain, and project configuration, read references/tooling/toolchain.md。
• When copyable task examples are needed, read by scenario examples/, and there is no need to load them all at once.