Add OpenSkills agent skill: swiftfindrefs

README.md

@@ -50,6 +50,32 @@ Sample output:
 2. **Index routing** – `DerivedDataPaths` ensures the path points into `Index.noindex/DataStore/IndexStoreDB` so we can open the index without extra setup.
 3. **Output formatting** – Paths are normalized, deduplicated, and printed once for easier scripting.
 
+## Agent Skill (OpenSkills)
+
+This repository includes an OpenSkills-compatible agent skill located in `swiftfindrefs/`.
+It teaches AI coding agents to use IndexStore-based reference discovery via `swiftfindrefs`
+instead of unreliable text search.
+
+### Install OpenSkills
+```bash
+npm i -g openskills
+```
+
+### Install this skill
+```bash
+openskills install michaelversus/SwiftFindRefs
+```
+
+### Sync into your project
+```bash
+openskills sync
+```
+
+### Example agent prompt
+Use the swiftfindrefs skill to find all references to `SelectionViewController` (class) and add
+`import UIComponents` only where missing.
+
+
 ## 🧪 Testing
 The package uses the Swift Testing framework (`swift test`) with mocks for filesystem and derived-data resolution. Tests cover locator edge cases, path building, and index error handling.
 

swiftfindrefs/SKILL.md

@@ -0,0 +1,75 @@
+---
+name: swiftfindrefs
+description: Use swiftfindrefs (IndexStoreDB) to list every Swift source file referencing a symbol. Mandatory for “find references”, “fix missing imports”, and cross-module refactors. Do not replace with grep/rg or IDE search.
+---
+
+# SwiftFindRefs
+
+## Purpose
+Use `swiftfindrefs` to locate every Swift source file that references a given symbol by querying Xcode’s IndexStore (DerivedData). This skill exists to prevent incomplete refactors caused by text search or heuristics.
+
+## Rules
+- Always run `swiftfindrefs` before editing any files.
+- Only edit files returned by `swiftfindrefs`.
+- Do not substitute `grep`, `rg`, IDE search, or filesystem heuristics for reference discovery.
+- Do not expand the file set manually.
+- If IndexStore/DerivedData resolution fails, stop and report the error. Do not guess.
+
+## Preconditions
+- macOS with Xcode installed
+- Project has been built at least once (DerivedData exists)
+- `swiftfindrefs` available in PATH
+
+## Canonical command
+Prefer providing `--projectName` and `--symbolType` when possible.
+
+```bash
+swiftfindrefs \
+  --projectName <XcodeProjectName> \
+  --symbolName <SymbolName> \
+  --symbolType <class|struct|enum|protocol|function|variable>
+```
+
+Optional flags:
+- `--derivedDataPath <path>`: explicit DerivedData (or IndexStoreDB) path; skips discovery
+- `--verbose`: prints discovery steps, resolved paths, and diagnostics
+
+## Output contract
+- One absolute file path per line
+- Deduplicated
+- Script-friendly (safe to pipe line-by-line)
+- Ordering is not semantically meaningful
+
+## Standard workflows
+
+### Workflow A: Find all references
+1. Run `swiftfindrefs` for the symbol.
+2. Treat the output as the complete reference set.
+3. If more detail is needed, open only the returned files.
+
+### Workflow B: Fix missing imports after moving a symbol
+Use `swiftfindrefs` to restrict scope, then add imports only where needed.
+
+```bash
+swiftfindrefs -p <Project> -n <Symbol> -t <Type> | while read file; do
+  if ! grep -q "^import <ModuleName>$" "$file"; then
+    echo "$file"
+  fi
+done
+```
+
+Then for each printed file:
+- Insert `import <ModuleName>` in the imports block at the top.
+- Preserve existing import ordering/grouping.
+- Never add duplicate imports.
+- Do not reformat unrelated code.
+
+### Workflow C: Audit usage before deleting or renaming a symbol
+1. Run `swiftfindrefs` for the symbol.
+2. If output is empty, treat the symbol as unused (still validate via build/tests if needed).
+3. If non-empty, review the listed files before changing public API.
+
+## References
+- CLI details: references/cli.md
+- Playbooks: references/workflows.md
+- Troubleshooting: references/troubleshooting.md

swiftfindrefs/references/cli.md

@@ -0,0 +1,46 @@
+# CLI reference (agent-focused)
+
+## Preconditions
+- macOS with Xcode installed
+- Project built at least once (DerivedData exists)
+- `swiftfindrefs` is available in PATH
+
+## Flags
+- `-p, --projectName`
+  Helps infer the correct DerivedData folder when `--derivedDataPath` is not provided.
+
+- `-d, --derivedDataPath`
+  Points directly to a DerivedData (or IndexStoreDB) directory and skips discovery.
+
+- `-n, --symbolName` (required)
+  The symbol to inspect.
+
+- `-t, --symbolType`
+  Narrows matches to a specific kind (recommended when possible).
+
+- `-v, --verbose`
+  Prints discovery steps, resolved paths, and diagnostics.
+
+## Recommended invocations
+
+Most common:
+```bash
+swiftfindrefs -p MyApp -n SelectionViewController -t class
+```
+
+Explicit DerivedData / deterministic runs:
+```bash
+swiftfindrefs -d ~/Library/Developer/Xcode/DerivedData/MyApp-XXXX/ -n SelectionViewController -t class
+```
+
+Debug discovery:
+```bash
+swiftfindrefs -p MyApp -n SelectionViewController -t class -v
+```
+
+## Output
+- Absolute file paths, one per line
+- Deduplicated
+
+## Non-goals
+- The tool reports which files reference a symbol, not line or column positions.

swiftfindrefs/references/troubleshooting.md

@@ -0,0 +1,18 @@
+# Troubleshooting
+
+## No results returned
+- Build the project in Xcode to regenerate indexing.
+- Re-run with verbose logging:
+  ```bash
+  swiftfindrefs -p <Project> -n <Symbol> -t <Type> -v
+  ```
+- If multiple DerivedData folders exist for the same project `swiftfindrefs` will use the most recent one.
+
+## Wrong DerivedData selected
+- Prefer explicit `--derivedDataPath` in CI or multi-clone setups.
+- Use `--verbose` to confirm path selection.
+
+## Do not fall back to grep
+- Text search is not acceptable for reference discovery.
+- grep/rg may only be used inside files already returned by `swiftfindrefs`
+  (for example, to check if an import already exists).

swiftfindrefs/references/workflows.md

@@ -0,0 +1,30 @@
+# Workflows (deterministic behavior)
+
+## Golden rule
+Reference discovery must be IndexStore-based. `swiftfindrefs` output defines scope.
+
+## Playbook: add missing imports after moving a symbol
+Inputs:
+- Project: `<Project>`
+- Symbol: `<Symbol>`
+- Type: `<Type>`
+- Module to import: `<Module>`
+
+Steps:
+1. Run:
+   ```bash
+   swiftfindrefs -p <Project> -n <Symbol> -t <Type>
+   ```
+2. Iterate only over the resulting file list.
+3. For each file:
+   - If `import <Module>` exists: no change.
+   - Else: add it to the imports block at the top.
+4. Keep edits minimal:
+   - No formatting changes
+   - No unrelated cleanup
+   - Preserve existing import ordering/grouping
+
+## Playbook: rename or delete a symbol
+1. Run `swiftfindrefs` on the symbol.
+2. If output is empty, treat as unused (validate via build/tests).
+3. If non-empty, update usages only in returned files.