What

This PR refactors the block-inspector/index.js component to eliminate duplication, improve code readability, and reduce maintenance burden while preserving all existing functionality.

Key Changes:

• Extract duplicated InspectorControls.Slot patterns into StyleInspectorSlots component
• Extract content panel logic into ContentPanel component
• Inline both components to reduce file complexity
• Eliminate borderPanelLabel prop drilling by calculating internally
• Simplify conditional logic with well-named inline variables
• Consolidate duplicate useInspectorControlsTabs calls for better performance
• Improve variable names (count → selectedBlockCount)
• Remove unnecessary API noise (hasMultipleTabs prop)

Why

The block-inspector/index.js component had several maintainability issues that made it difficult to work with:

1. Significant Code Duplication

• 30+ lines of identical InspectorControls.Slot patterns were duplicated in two places (multi-selection and single block rendering)
• Duplicate useInspectorControlsTabs calls with identical parameters
• Similar conditional rendering patterns repeated throughout the component

2. Poor Code Readability

• Unclear variable names like count (count of what?)
• Complex boolean expressions that required mental parsing
• Inconsistent conditional logic with similar patterns expressed differently

3. Performance Inefficiencies

• Duplicate hook calls - useInspectorControlsTabs called twice with same parameters
• Unnecessary prop drilling - calculated values passed down instead of computed locally

4. Maintenance Burden

• Changes required in multiple places - style slot modifications needed updates in two locations
• Tight coupling - components dependent on parent calculations
• API complexity - unnecessary props being passed around

How

Eliminated Duplication

• Created StyleInspectorSlots component to consolidate all style-related inspector control slots
• Created ContentPanel component to encapsulate content panel logic
• Inlined both components to reduce file complexity while maintaining reusability

Improved Readability

• Replaced complex boolean expressions with well-named variables:
  • count > 1 && ! isSectionBlock → isMultiSelection
  • ! blockType || ! selectedBlockClientId || isSelectedBlockUnregistered → shouldShowWarning
• Renamed unclear variables: count → selectedBlockCount

Optimized Performance

• Consolidated useInspectorControlsTabs calls - now called once in parent and passed down
• Eliminated unnecessary prop drilling by having components calculate their own derived values

Simplified APIs

• Removed hasMultipleTabs prop - child component calculates this locally
• Eliminated borderPanelLabel prop drilling - component calculates its own label

Testing

• All existing functionality preserved
• No visual or behavioral changes
• All conditional rendering logic works identically
• Performance improved with fewer hook calls

To confirm existing functionality is preserved ensure the displayed tabs and controls for this branch match trunk using:

• a section block, template parts, unsynced patterns, and synced patterns
• a regular individual block selection
• a mutli-selection with only non-section blocks
• a multi-selection including a section block

Additionally,

Rationale for Value

This refactoring provides genuine value by solving real problems developers face:

1. Maintenance Efficiency - Style slot changes now only need to be made in one place
2. Developer Experience - Code reads like plain English with self-documenting variable names
3. Runtime Performance - Eliminated duplicate hook calls
4. Reduced Coupling - Components are more self-contained and easier to reason about
5. Cleaner Interfaces - Only essential data is passed between components
6. Future-Proofing - Makes the component more open to change for upcoming features

Preparing for Simplified Editing Experience (WP 6.9)

This refactoring is particularly important as we prepare for the Simplified Editing Experience work planned for WordPress 6.9. The current monolithic structure of the block inspector would make it difficult to:

• Modify inspector behavior for different editing modes
• Add new conditional rendering logic for simplified interfaces
• Extract or reorganize inspector panels based on user preferences
• Implement dynamic inspector layouts that adapt to the editing context

By breaking the component into smaller, focused pieces with clear responsibilities, we create a foundation that can more easily accommodate the architectural changes needed for the simplified editing experience.

This is not refactoring for its own sake - each change addresses a specific maintainability or performance issue that developers encounter when working with this component, while also preparing the codebase for future enhancements.

Screenshots

No visual changes - this is a pure refactoring that preserves all existing functionality.