refactor

Project Context

• git installed: !which git 2>/dev/null || echo "not installed"
• current branch: !git branch --show-current 2>/dev/null || echo unknown
• working tree: !git status --porcelain 2>/dev/null | head -5
• CLAUDE.md: !find . -maxdepth 1 -name "CLAUDE.md" -type f
• project-discovery.md: !find . -maxdepth 3 -name "project-discovery.md" -type f
• personal config directory: !bash "${CLAUDE_PLUGIN_ROOT}/scripts/han-config-dir.sh" 2>/dev/null || echo "$HOME/.claude"
• project .han/config.md: !cat .han/config.md 2>/dev/null || echo ""

As your first action, use the Read tool on .han/config.md inside the personal config directory path above. A read that returns no file is no personal configuration: continue silently. When that file or the project .han/config.md probe supplies content, apply it per config-rule.md, which governs precedence between the two files, relative-path resolution, and what to do with a file that reads but cannot be used.

Constraints (read before anything else)

This skill restructures existing production and test code in your working tree. It is an execution skill, not a document generator. These constraints shape every step and override any instinct to move faster. The canon they derive from, with provenance, is in references/refactoring-discipline.md; pull that reference when a step needs the full rule or a step feels off.

• Behavior preservation is the definition. A refactoring changes internal structure without changing observable behavior. A change that alters behavior is not a refactoring done badly; it is not a refactoring at all. When a planned step turns out to require a behavior change, it leaves this skill's scope: defer it with a note naming the behavior change it needs.
• Tests are the license to refactor. No edit until the full suite has been run, observed green, and the target's behavior is covered. If coverage of the target cannot be established, stop and offer the characterization path in the reference; never refactor blind.
• Small named steps, green to green. Each step is one named refactoring with a bounded mechanic (extract function, rename, move, inline, and so on), and the suite runs after every step. A red suite after a step means revert the step, not patch forward.
• The declared scope is a contract. The target named in Step 1 bounds every edit. When a step starts pulling in files outside that scope, stop, report the spread, and let the user re-scope. Spreading edits are how a refactoring silently becomes a rewrite.
• Never alongside an active tdd loop. If the working tree shows a red-green cycle in flight (failing tests, a half-implemented behavior), do not run: the refactor step of /tdd owns cleanup inside the loop, and restructuring while a test is red violates the two-hats rule both skills share.
• Refactor-only changes. No behavior fixes, no features, no drive-by bug fixes, even when you spot one. Record what you found and leave it. If the user asks for commits, each commit contains refactoring only.
• YAGNI governs the plan. Apply ../../references/yagni-rule.md: every refactoring in the plan needs evidence the code has a reason to change (a review finding, named duplication, a confusing read documented by the user, upcoming work in that area). Removing duplication is the job; adding speculative abstraction, configuration, or indirection is not. Defer evidence-free items with a reopen trigger.