Summary

This PR adds explicit parameter type hints to key methods across Laravel's core classes that were missing them, improving type safety and developer experience.

Changes Made

Str Class Improvements

• length(): Added string $value, ?string $encoding = null parameter types with : int return type
• lower(): Added string $value parameter type with : string return type
• upper(): Added string $value parameter type with : string return type
• title(): Added string $value parameter type with : string return type
• reverse(): Added string $value parameter type with : string return type

Arr Class Improvements

• shuffle(): Added array $array parameter type with : array return type
• isAssoc(): Added array $array parameter type with : bool return type
• isList(): Added array $array parameter type with : bool return type

Request Class Improvements

• segment(): Added int $index parameter type with : ?string return type
• __isset(): Added string $key parameter type with : bool return type

Key Benefits

Enhanced Type Safety

• Compile-time type checking prevents runtime type errors
• Earlier detection of type mismatches during development
• Better integration with static analysis tools like PHPStan

Improved Developer Experience

• Better IDE autocompletion and parameter hints
• Self-documenting method signatures with clear expectations
• Reduced cognitive load when working with these methods

Better Static Analysis

• More accurate PHPStan and Psalm analysis
• Enhanced code quality through stricter type checking
• Better detection of potential bugs before runtime

Code Quality Improvements

• Consistent type declarations across framework methods
• Modern PHP development practices alignment
• Better maintainability and readability

Technical Details

Backward Compatibility

• All changes are fully backward compatible
• Parameter types match existing usage patterns
• No breaking changes for existing applications

Performance Impact

• Zero runtime performance overhead
• Compile-time type checking only
• No behavioral changes to existing functionality

Safety Considerations

• Only added type hints where the existing code already enforced these types
• Maintained nullable parameters where appropriate
• Preserved default parameter values and behavior

Testing

• All existing tests pass without modification
• Static analysis tools report improved type coverage
• No functional changes to existing behavior
• IDE support significantly enhanced

Examples

// Before: No parameter type checking
Str::length($someVariable); // Could pass any type
Arr::shuffle($someVariable); // Could pass any type

// After: Compile-time type safety
Str::length('hello world'); // ✓ string parameter enforced
Arr::shuffle(['a', 'b', 'c']); // ✓ array parameter enforced

// Type errors caught early:
Str::length(123); // ✗ TypeError at compile time
Arr::shuffle('not an array'); // ✗ TypeError at compile time

Future Impact

This change establishes a foundation for:

• Continued type safety improvements across the framework
• Better developer tooling integration
• Enhanced code reliability and maintainability
• Consistent typing patterns for future development

This enhancement significantly improves type safety while maintaining Laravel's commitment to backward compatibility and ease of use.