codeguard-swift

Swift Codeguard Gate

Goal: Turn "looks fine" into repeatable tool evidence, and honestly distinguish pass, fail, unable to verify, and planned.

Start in 30 seconds

1. At the repository root, confirm Package.swift or that the target file exists.
2. Detect tools:swiftlint --version。
3. First perform a read-only check:swiftlint。
4. Classify results as: code violations, missing configuration, missing tools, tool internal errors.
5. Only perform safe fixes:swiftlint --fix。
6. Re-run lint, and execute the project's existing test/build gates.

Can directly request:

• "Check this Swift project, do not modify anything first, and give me the lint failure classification."
• "Only fix Swift formatting issues; list semantic issues first."
• "Verify Swift lint, test, and build evidence before committing."

Capability boundaries

✅ Good at handling

1. Based on .swift and project markers, identify the Swift workspace.
2. Run swiftlint and preserve exit code, scope, and tool version.
3. Distinguish formatting, static rules, configuration, dependency, and environment failures.
4. Use swiftlint --fix to handle reversible issues and rescan.
5. Report local results in layers with CI/build/test evidence.

⚠️ Requires conditions

1. The target tool must already 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 prevails.
4. Whether generated code, vendor, and cache directories are scanned must follow repository rules.

❌ Not applicable

1. Do not treat formatter pass as compilation, test, or security audit pass.
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 "check passed" when tools or configuration are missing.

When to use

• The user requests checking or fixing Swift code standards.
• The AI modified .swift, requiring pre-commit verification.
• CI has failures related to swiftlint .
• Need to determine whether a certain issue can be fixed automatically, or must be handled manually.

When not to use

• The main task is learning language syntax, framework design, or business modeling; corresponding language professional skills should be used instead.
• The main task is dependency vulnerabilities, security audit, or license governance; specialized security skills should be used.
• When the user only requests an explanation of 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, 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 V0.2)
File Extensions	.swift
Project Markers	Package.swift
Onboarding Configuration	Based on the repository's existing configuration
Tool Preparation	brew install swiftlint
Probe Command	使用命令查找与项目配置检查
lint	swiftlint
format/fix	swiftlint --fix
Project-level gate	swiftlint

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 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 fail to load are all recorded as "Unable to verify," not as a pass.

Step 4: Run Read-Only Checks

Run swiftlint, 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 allowed, then check the diff
Static Rules	unused, complexity, naming, dangerous APIs	Minimal semantic fix; no bulk guesswork
Configuration	parser/config/schema not found	Fix onboarding or report prerequisites
Environment	command not found, version conflicts	Report installation/version requirements; do not install silently
Tool Internal Error	crash, timeout, parser exception	Preserve raw evidence and narrow the reproduction scope

Step 6: Controlled Fixes

Prioritize running swiftlint --fix. Only handle issues that are definitively 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 "passed" 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

Swift 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. 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 cause missed detections 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 entire repository.

Domain pitfalls and fixes

1. Domain pitfalls — SwiftLint rules come from the repository configuration; do not override the team's configuration with a personal global .swiftlint.yml。

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 automatic fixes are allowed.

FAQ

Q1: If the tool is not installed, can the code be judged as 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 too many changes be avoided at once? Fix in batches by failure category and file first; rerun the original command and review the diff for each batch.

Q6: If it passes locally, can you say CI will pass? No. CI's version, environment variables, operating system, and command scope must also be aligned.

Load resources on demand

• When encountering exit codes, failure classifications, 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 all of them at once.