batch-operations

# Batch Operations — Multi-File Changes > Apply consistent changes across many files at once. One pattern, many targets. ## When to Use ✅ **Good for:** - Renaming a function/component across all files that use it - Adding an import to every file in a directory - Updating version numbers across package files - Applying the same code pattern to multiple similar files - Migrating from one API to another across the codebase - Adding/removing a field from all similar data structures ❌ **Not for:** - Single-file edits (use direct editing) - Unique changes per file (handle individually) - Changes that need per-file judgment (use an agent per domain) --- ## Batch Operation Protocol ### Step 1: Define the Pattern ``` What: [exact text/pattern to find] Replace: [exact replacement text] Scope: [file glob pattern, e.g., "src/**/*.tsx"] Exclude: [files to skip, e.g., "**/*.test.tsx"] ``` ### Step 2: Preview Before Executing ```bash # Find all affected files FIRST grep -rl "oldPattern" src/ --include="*.ts" # Count matches grep -rc "oldPattern" src/ --include="*.ts" | grep -v ":0$" # Show context for each match grep -rn "oldPattern" src/ --include="*.ts" ``` > 🔴 **NEVER batch-modify without previewing first.** Show the user what will change. ### Step 3: Execute the Batch For text replacements: ```bash # On Linux/macOS find src -name "*.ts" -exec sed -i 's/oldPattern/newPattern/g' {} + # On Windows (PowerShell) Get-ChildItem -Path src -Recurse -Filter *.ts | ForEach-Object { (Get-Content $_) -replace 'oldPattern','newPattern' | Set-Content $_ } ``` For structural changes (adding imports, wrapping code): - Use the Edit tool on each file - Process files in a consistent order (alphabetical or by dependency) ### Step 4: Verify the Batch ```bash # Confirm no missed instances grep -rl "oldPattern" src/ --include="*.ts" # Should return empty # Confirm replacements are correct grep -rn "newPattern" src/ --include="*.ts" | head -5 # Run tests to catch breakage npm run test npm run build ``` --- ## Common Batch Patterns | Operation | Command Pattern | |---|---| | **Rename import** | Find all `import { X }` → replace with `import { Y }` | | **Update version** | Find `"version": "1.0"` → replace across all package.json | | **Add export** | Append `export { X }` to all index files | | **Remove deprecated** | Find `deprecatedFn()` → replace with `newFn()` | | **Add header** | Prepend license header to all source files | | **Type migration** | Find `interface X` → replace with `type X =` | --- ## Safety Rules 1. **Preview first** — always show affected files before modifying 2. **Git safety** — ensure clean working directory (`git stash` or commit first) 3. **Exclude tests** — often tests need different treatment than source 4. **Verify after** — run build + tests after every batch operation 5. **Report changes** — list every file modified with change summary