feature-toggle-developer

Feature Toggle Developer

Status: Active Auto-activates on: Feature flag/toggle removal, cleanup after refactoring toggles Related Skills: code-generation-developer, ios-dev-guidelines, code-review-developer

Purpose

Guides the systematic removal of feature toggles (feature flags) from the codebase with automated cleanup detection. Ensures no orphaned code, unused components, or forgotten files remain after toggle removal.

When This Skill Activates

• User mentions: "remove toggle", "delete feature flag", "enable feature toggle permanently"
• User edits: FeatureDescription+Flags.swift
• After completing toggle removal: helps identify cleanup opportunities

Feature Toggle Removal Workflow

Phase 1: Pre-Removal Analysis

Before removing any toggle, gather complete information:

1. Find the toggle definition:

   # Location: Modules/AnytypeCore/AnytypeCore/Utils/FeatureFlags/FeatureDescription+Flags.swift
   rg "static let toggleName" --type swift
   

2. Check the defaultValue to determine which branch to keep:

   • defaultValue: true → Keep the TRUE branch, remove FALSE branch
   • defaultValue: false → Keep the FALSE branch, remove TRUE branch

3. Search for ALL usages:

   rg "toggleName" --type swift
   

4. Identify usage patterns:

   • Direct: if FeatureFlags.toggleName { ... }
   • Inverted: if !FeatureFlags.toggleName { ... } or guard !FeatureFlags.toggleName
   • Compound: if FeatureFlags.toggleName && otherCondition { ... }
   • Assignment: let value = FeatureFlags.toggleName ? a : b
   • State: @State private var toggle = FeatureFlags.toggleName

5. List affected files and present to user for review

Phase 2: Toggle Removal

Systematic removal process:

1. Remove conditional checks and simplify:

   Example 1 - Simple conditional (defaultValue: true):

   // BEFORE
   if FeatureFlags.toggleName {
       // feature code
   }
   
   // AFTER (keep true branch)
   // feature code
   

   Example 2 - Ternary operator (defaultValue: true):

   // BEFORE
   VStack(spacing: FeatureFlags.toggleName ? 8 : 0)
   
   // AFTER
   VStack(spacing: 8)
   

   Example 3 - Inverted logic (defaultValue: true):

   // BEFORE
   guard !FeatureFlags.toggleName else { return }
   oldCode()
   
   // AFTER (flag is true, so guard fails, remove entire block)
   // [entire block deleted]
   

   Example 4 - State variable (defaultValue: true):

   // BEFORE
   @State private var toggle = FeatureFlags.toggleName
   if toggle { newUI() } else { oldUI() }
   
   // AFTER
   newUI()
   // Note: @State variable removed in cleanup phase
   

2. Remove feature flag definition:

   // Delete from: Modules/AnytypeCore/AnytypeCore/Utils/FeatureFlags/FeatureDescription+Flags.swift
   static let toggleName = FeatureDescription(...)
   

3. Run code generation:

   make generate
   

   This updates FeatureFlags+Flags.swift automatically.

4. Verify removal:

   rg "toggleName" --type swift  # Should return no results
   

Phase 3: Automated Cleanup Detection ⭐

CRITICAL: After toggle removal, systematically check for orphaned code:

3.1 Unused State Variables

Search for @State variables that were only used for the toggle:

# Look for patterns like: @State private var someToggle = FeatureFlags.toggleName
rg "@State.*=.*FeatureFlags" --type swift

Action: Remove the entire @State variable declaration if it's no longer used.

3.2 Unused View Components

When a toggle controlled which UI component to show, one component may now be unused:

Detection Pattern:

• Toggle switched between ComponentA and ComponentB
• After removal, only one is used
• Search for the unused component's name across codebase

Example from vaultBackToRoots:

// BEFORE
if !vaultBackToRootsToggle {
    SpaceCardLabel(...)  // This became unused
} else {
    NewSpaceCardLabel(...)
}

// AFTER
NewSpaceCardLabel(...)

// CLEANUP: SpaceCardLabel is now unused
rg "SpaceCardLabel" --type swift  # Check if used anywhere else
# If only in its own file → DELETE the file

Action:

1. Search for unused component name: rg "UnusedComponentName" --type swift
2. If only found in its definition file and comments → DELETE the file
3. Update references in comments

3.3 Unused ViewModels / Service Classes

Toggle removal may leave entire classes unused:

Detection:

# For each major component that was conditionally used:
rg "UnusedViewModel" --type swift
rg "class UnusedViewModel" --type swift

Action: Delete unused ViewModels, their files, and DI registrations.

3.4 Unused Imports

After simplification, import AnytypeCore may only have been needed for FeatureFlags:

Detection:

• File imports AnytypeCore
• Only usage was FeatureFlags.toggleName
• After removal, no other AnytypeCore usage

Action: Remove unused import.

3.5 Orphaned Parameters / Properties

Toggle-gated functionality may have parameters that are no longer needed:

Example:

// BEFORE
func configure(showFeature: Bool) {
    if showFeature && FeatureFlags.toggle { ... }
}

// AFTER toggle removal
func configure(showFeature: Bool) {
    if showFeature { ... }
}

// POTENTIAL CLEANUP: Is showFeature still needed?

Action: Review function signatures and remove unnecessary parameters.

3.6 Test Cleanup

Toggle removal affects tests:

Check:

1. Mock objects with toggle-related properties
2. Test cases specifically for toggle behavior
3. Test setup code with toggle configurations

Files to check:

rg "toggleName" AnyTypeTests/ --type swift
rg "toggleName" "Anytype/Sources/PreviewMocks/" --type swift

Action: Update or remove tests for deleted code paths.

Phase 4: Final Verification

Before committing:

1. Grep verification:

   rg "toggleName" --type swift  # Should be empty
   

2. Compilation check:

   • Remind user to verify compilation in Xcode
   • Claude cannot verify this due to caching

3. Generate updated commit message:

   IOS-XXXX Removed [toggleName] toggle
   

4. Review cleanup summary:

   • List all files modified
   • List all files deleted
   • Note any remaining manual checks needed

Cleanup Checklist Template

Use this checklist after every toggle removal:

## Cleanup Verification for [toggleName]

- [ ] Toggle definition removed from FeatureDescription+Flags.swift
- [ ] `make generate` run successfully
- [ ] All conditional usage removed
- [ ] No grep results for toggle name
- [ ] Unused @State variables removed
- [ ] Unused view components identified and deleted
- [ ] Unused ViewModels/services deleted
- [ ] Unused imports removed (especially AnytypeCore)
- [ ] Orphaned function parameters removed
- [ ] Tests updated (check AnyTypeTests/ and PreviewMocks/)
- [ ] Comments referencing old component updated
- [ ] Xcode compilation verified (by user)

Common Patterns & Pitfalls

Inverted Logic

Watch out for !FeatureFlags.toggle:

// If defaultValue: true
if !FeatureFlags.toggle {
    oldCode()  // This branch NEVER runs, delete it
}

Compound Conditions

Simplify conditions properly:

// BEFORE (defaultValue: true)
if FeatureFlags.toggle && userHasPermission {
    showFeature()
}

// AFTER
if userHasPermission {
    showFeature()
}

Guard Statements

Be careful with guards:

// BEFORE (defaultValue: true)
guard !FeatureFlags.toggle else { return }
performOldBehavior()

// AFTER (toggle is true, guard returns, entire block is dead code)
// DELETE ENTIRE BLOCK

Integration with Other Skills

• code-generation-developer: References for make generate command and troubleshooting
• ios-dev-guidelines: Swift refactoring patterns, import management
• code-review-developer: Cleanup standards, ensuring no orphaned code in PRs