codeguard-go

Go Codeguard Gate

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

Start in 30 seconds

1. At the repository root, confirm go.mod or the target file exists.
2. Detect tools:go --version。
3. First perform a read-only check:go vet ./...。
4. Classify results as: code violations, missing configuration, missing tools, tool internal errors.
5. Only perform on safely fixable items:gofmt -w .。
6. Rerun lint, and execute the project's existing test/build gates.

Can directly propose:

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

Capability Boundaries

✅ Good at handling

1. Based on .go and project markers, identify the Go workspace.
2. Execute go vet ./... and retain the exit code, scope, and tool version.
3. Distinguish formatting, static rules, configuration, dependency, and environment failures.
4. Use gofmt -w . to handle reversible issues and rescan.
5. Report local results in layers with CI/build/test evidence.

⚠️ Conditions required

1. The target tool must already be installed and its version must be compatible with the 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.

❌ Out of scope

1. Do not treat formatter passing as compilation, test, 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 problems.
4. Do not claim "check passed" when tools or configuration are missing.

When to use

• The user requests checking or fixing Go code standards.
• AI modified .go, and pre-commit verification is needed.
• CI has failures related to go vet ./... .
• Need to determine whether a problem 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, and the corresponding language professional skill should be used instead.
• The main task is dependency vulnerabilities, security auditing, or license governance, and a specialized security skill should be used.
• 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

Item	Current Fact
Status	stable(Since Codeguard V0.2)
File Extensions	.go
Project Markers	go.mod
Integration Configuration	go.mod
Tool Preparation	Built into the Go toolchain; aggregated lint can be installed with golangci-lint
Detection Command	使用命令查找与项目配置检查
lint	go vet ./...
format/fix	gofmt -w .
Project-level gate	go vet ./...

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 that will be scanned; never guess based on the current directory.

Step 2: Read the project contract

Read go.mod and the actual commands in CI. Repository configuration takes precedence over this skill's examples; if the two conflict, report the difference first.

Step 3: Detect tools and versions

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

Step 4: Run read-only checks

Run go vet ./..., 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	Formatter is allowed, then check 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 prerequisite
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

Prefer running gofmt -w .. Only handle issues that are clearly 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. 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, 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 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

Go 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 — you must output UNVERIFIED and a clear preparation method.
2. 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} must be replaced with real, authorized paths.
5. Auto-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 scan or modify third-party content across the entire repository at will.

Domain pitfalls and fixes

1. Domain pitfall — gofmt only handles formatting;go vet and go test still need to be run independently.
2. Domain pitfall — a multi-module repository may contain multiple go.mod, and executing from the wrong root directory will miss issues.

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. An exemption is only allowed 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 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. You also need to align the 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 this language's registry, toolchain, and project configuration, read references/tooling/toolchain.md。
• When you need copyable task examples, read by scenario examples/, there is no need to load everything at once.