Code Check

Code Checking Skill

This skill provides code validation and linting operations for the project codebase.

When to Use This Skill

Use this skill when you need to:

• Validate Rust code after making changes
• Run compiler checks without building
• Lint code with clippy
• Ensure code quality before commits or PRs

Command Selection Rules

Choose the appropriate command based on how many crates were edited:

Decision process:

1. Identify which crates contain your edited files
2. If 2 or more crates: use workspace-wide commands (just check / just clippy)
3. If exactly 1 crate: use per-crate commands (just check-crate / just clippy-crate)
4. Public API rule: If the single crate's public API changed (public types, traits, functions, re-exports), also run the workspace-wide commands to catch downstream breakage

Available Commands

Check Rust Code

just check [EXTRA_FLAGS]

Checks Rust code using cargo check --all-targets. This runs the compiler without producing binaries.

Examples:

• just check - check all Rust code
• just check --release - check with release optimizations

Check Specific Crate

just check-crate <CRATE> [EXTRA_FLAGS]

Checks a specific crate with all its targets using cargo check --package <CRATE> --all-targets.

Examples:

• just check-crate metadata-db - check the metadata-db crate
• just check-crate common --release - check common crate with release mode

Lint Rust Code (Clippy)

just clippy [EXTRA_FLAGS]

Lints all Rust code using cargo clippy --all-targets. Clippy catches common mistakes and suggests improvements.

Examples:

• just clippy - lint all code
• just clippy -- -D warnings - treat warnings as errors

Lint Specific Crate

just clippy-crate <CRATE> [EXTRA_FLAGS]

Lints a specific crate using cargo clippy --package <CRATE> --all-targets --no-deps.

The --no-deps flag ensures clippy only analyzes the specified crate's code, not its dependencies. This provides:

• Faster execution: Skip checking dependency code you don't control
• Focused output: See only warnings from your crate, not transitive dependencies
• Actionable results: All warnings shown are in code you can fix

Examples:

• just clippy-crate admin-api - lint the admin-api crate only
• just clippy-crate dataset-store -- -D warnings - lint with warnings as errors

Important Guidelines

MANDATORY: Run Checks After Changes

You MUST run checks after making code changes. Use the Command Selection Rules above to choose the right command.

Before considering a task complete: all checks MUST pass AND all clippy warnings MUST be fixed.

Example Workflows

Single crate, internal changes only:

1. Edit files in metadata-db crate (no public API changes)
2. Format: use /code-format skill
3. Check compilation: just check-crate metadata-db
   • If errors → fix → return to step 2
4. Check clippy: just clippy-crate metadata-db
   • If warnings → fix ALL → return to step 2
5. Repeat until: zero compilation errors AND zero clippy warnings

Single crate, public API changed:

1. Edit files in metadata-db crate (changed a public type/trait/function)
2. Format: use /code-format skill
3. Check compilation: just check-crate metadata-db, then just check
   • If errors → fix → return to step 2
4. Check clippy: just clippy-crate metadata-db, then just clippy
   • If warnings → fix ALL → return to step 2
5. Repeat until: zero compilation errors AND zero clippy warnings

Multiple crates (2+ crates edited):

1. Edit files across multiple crates
2. Format: use /code-format skill
3. Check compilation: just check
   • If errors → fix → return to step 2
4. Check clippy: just clippy
   • If warnings → fix ALL → return to step 2
5. Repeat until: zero compilation errors AND zero clippy warnings

Common Mistakes to Avoid

❌ Anti-patterns

• Never run cargo check directly - Use just check-crate or just check
• Never run cargo clippy directly - Justfile adds proper flags like --no-deps
• Never ignore clippy warnings - Clippy is enforced in CI, warnings will fail builds
• Never skip the check step - Even if "it should compile"
• Never use global commands when only 1 crate's internals changed - Use per-crate commands for efficiency
• Never use per-crate commands for 2+ crates - Use global commands for efficiency

✅ Best Practices

• Follow Command Selection Rules based on number of crates edited
• Use per-crate commands for 1 crate with internal-only changes (faster, focused feedback)
• Use global commands for 2+ crates or when a public API changed (catch downstream breakage)
• Fix compilation errors before running clippy
• Run clippy when you finish a coherent chunk of work or before committing
• Document any warnings you absolutely cannot fix (rare exception)

Pre-approved Commands

These commands can run without user permission:

• just check - Safe, read-only compilation check
• just check-crate <crate> - Safe, read-only compilation check
• just clippy - Safe, read-only linting
• just clippy-crate <crate> - Safe, read-only linting

Next Steps

After all checks pass:

1. Run targeted tests when warranted → See .claude/skills/code-test/SKILL.md
2. Commit changes → Ensure all checks green first