Swift refactor plan

What this skill does

Builds a written plan for a Swift refactor. It does not edit code. The plan is what you hand to the user (or to swift-rename-symbol) so the actual edits can happen with full context.

A good plan answers four questions:

1. What's the target? A specific symbol, or a file as a unit.
2. What sites will change? Every reference, grouped by file and line.
3. What can go wrong? Overrides, conformances, @objc bridging, public API crossing module boundaries, missing test coverage.
4. How should it be executed? A specific recommended path — swift-rename-symbol, manual edits in N files, or "this needs more design work first."

The xcindex MCP tools provide the raw data; this skill orchestrates the queries and turns the result into a plan.

How to use

Step 1 — Decide the target shape

The user's phrasing tells you whether the unit is a symbol or a file.

• "Rename fetchUser to loadUser" → symbol.
• "What if I split NetworkClient.swift into two files" → file.
• "Migrate from OldAuthAPI to NewAuthAPI" → multiple symbols (treat each separately, then aggregate).

If the user named only a file but the change is really about a symbol inside it (e.g. "what if I change the signature of the function in Auth.swift"), disambiguate before querying.

Step 2 — Gather data

Run only the queries that match the target shape. Skip anything irrelevant.

Symbol target:

1. find_symbol(symbolName: <name>) → resolve to a USR. If multiple results, pick the one matching the user's stated module/kind, or ask.
2. find_definition(usr: <usr from step 1>) → confirm the definition site.
3. find_references(symbolName: <name>, maxResults: 200) → every reference.
4. If the symbol is a method or property: find_overrides(usr: <usr from step 1>) — subclass overrides break silently if missed.
5. If the symbol is a protocol or protocol requirement: find_conformances(usr: <usr from step 1>) — every conformer must update.

File target:

1. blast_radius(filePath: <abs path>) → directDependents, affectedFiles, coveringTests.
2. Optionally narrow per-symbol with find_references for the specific symbols inside the file the user is changing.

Step 3 — Surface risks

Walk the results and flag each of these that applies:

Risk	Signal
Overrides	find_overrides returns ≥1 site — subclasses must change in lockstep.
Protocol conformances	find_conformances returns ≥1 site — every conformer must update.
@objc bridging	find_references returns sites with .dynamic role — Objective-C call sites outside the index may exist.
Cross-module public API	Reference sites span multiple modules — downstream packages may break.
No covering tests	blast_radius.coveringTests is empty for the affected files — regression risk; recommend adding one before the change.
Stale index	MCP returned a freshness warning — note that the plan may be incomplete until the user rebuilds.

A risk-free plan is fine — write "No notable risks" rather than inventing filler.

Step 4 — Write the plan

Use this exact structure so plans are skimmable and the user can act on them directly:

## Refactor plan: <one-line description>

**Target:** <symbol or file, with USR if applicable>
**Type:** <rename | signature change | extraction | migration | other>
**Total impact:** <N files, M reference sites>

### Sites by file

- `path/to/A.swift` (<count>)
  - L<line> — <role: call | override | conformance | definition | test>
  - L<line> — ...
- `path/to/B.swift` (<count>)
  - ...

### Covering tests

- `path/to/ATests.swift`
- ...

(or "None — recommend adding test coverage before proceeding")

### Risks

- ⚠ <risk> — <one-sentence explanation>
- ✓ <thing-that-could-have-been-a-risk-but-isn't>

### Recommended execution

<one of:>
- Use `swift-rename-symbol` — dispatches the rename via the
  swift-refactor-specialist subagent. Estimated subagent context: ~Xk tokens
  (roughly: site count × 80 tokens/site + 200 tokens/file read).
- Manual edits in <list of files> — recommended when sites need
  case-by-case judgment (e.g. some calls need migration shims).
- Pause and decide on <X> first — recommended when the plan surfaces a design
  question the rename can't resolve (e.g. an `@objc` requirement, a behavior
  change disguised as a rename).

Step 5 — Hand off

End your message by telling the user what's available next:

• "Want me to dispatch this to swift-rename-symbol?" (if the recommendation is the automated path)
• "Want me to start with <file> so you can review the first edit?" (if manual)
• "Want me to look at <X> before we decide?" (if paused)

Don't start editing on your own — this skill's job ends with the plan.

Example

User: "I'm thinking about renaming fetchUser to loadUser. What would that touch?"

You:

1. find_symbol(symbolName: "fetchUser") → one USR, in MyApp.UserService.
2. find_references(symbolName: "fetchUser", maxResults: 200) → 11 sites across 6 files.
3. find_overrides(usr: "s:9MyApp11UserServiceC9fetchUserSiyF") → 0 (it's a free function on the class).
4. Review the role of each site (calls vs definition).

## Refactor plan: rename `UserService.fetchUser` → `loadUser`

**Target:** `s:9MyApp...fetchUserSiF` (UserService.fetchUser)
**Type:** rename
**Total impact:** 6 files, 11 sites

### Sites by file

- `Sources/UserService.swift` (2)
  - L42 — definition
  - L67 — internal call
- `Sources/AuthFlow.swift` (3)
  - L18, L24, L91 — calls
- `Sources/ProfileViewModel.swift` (2)
  - L33, L120 — calls
- `Tests/UserServiceTests.swift` (3)
  - L12, L45, L88 — calls
- `Tests/AuthFlowTests.swift` (1)
  - L23 — call

### Covering tests

- `Tests/UserServiceTests.swift`
- `Tests/AuthFlowTests.swift`

### Risks

- ✓ No subclass overrides.
- ✓ No protocol conformance — it's a concrete method.
- ✓ Not `@objc` — no Objective-C bridging surface.
- ✓ Tests cover both the direct method and one downstream caller.

### Recommended execution

Use `swift-rename-symbol` — straightforward rename, all sites are direct calls,
test coverage is solid. Estimated subagent context: ~2k tokens.

"Want me to dispatch this to swift-rename-symbol?"

When this skill won't help

• The user has already committed and just wants action — go to swift-rename-symbol directly.
• The change is a pure behavior change inside a single function with no API surface — there's nothing to plan; just edit.
• The user is asking a textual question ("how many places say TODO?") — that's Grep, not the index.

Related skills

• swift-rename-symbol — the execution path this plan often recommends.
• swift-find-references — the underlying query for symbol-level sites; use it directly when the user only wants the reference list.
• swift-blast-radius — the underlying query for file-level impact; use it directly when the user only wants the affected-files set.