Validation Contexts: Conditionally apply rules based on context

[CWAscend]

Summary

• Adds ability to define validation contexts (e.g., store, update, import) that conditionally apply validation rules
• All 85+ validation attributes now accept an optional context parameter
• Includes comprehensive test coverage for variadic parameter extraction

Backwards Compatibility

This is a fully backwards-compatible, non-breaking change:

• All validation attributes continue to work exactly as before without the context parameter
• Rules without a context defined apply to all contexts (existing behavior preserved)
• No existing method signatures have changed
• The context parameter is optional on all attributes
• Existing codebases require zero modifications to upgrade

Features

Context-specific validation rules:

class UserData extends Data
{
    public function __construct(
        #[Min(2)]
        public string $name,

        #[Email]
        public string $email,

        #[Min(8)]
        #[Confirmed]
        #[Required(context: 'store')] // Conditionally required only in 'store' context
        public ?string $password = null,

        public ?string $password_confirmation = null,
    ) {}
}

Controller integration with #[DataValidationContext]:

use Spatie\LaravelData\Attributes\DataValidationContext;

class UserController extends Controller
{
    #[DataValidationContext('store')]
    public function store(UserData $data): RedirectResponse
    {
        // Password is required and must be min 8 characters
    
        return redirect()->route('users.index')
            ->with('success', 'User created successfully.');
    }
    
    #[DataValidationContext('update')]
    public function update(UserData $data, User $user): RedirectResponse
    {
        // Password is optional - context-specific rules don't apply
    
        return redirect()->route('users.index')
            ->with('success', 'User updated successfully.');
    }
}

Multiple contexts per rule:

#[Required(context: ['store', 'import'])]
public ?string $email = null;

Fluent API:

UserData::withContext('store')->from($request);

Variadic rules with context:

#[In('draft', 'pending', context: 'store')]
#[In('published', 'archived', context: 'admin')]
public ?string $status = null;

You also have access to the string in your manual rules:

public static function rules(ValidationContext $context): array
{
    if ($context->contextName === 'store') {
        return [
            // Rules specific to the 'store' context
        ];
    }

    return [];
}

Test plan

• ValidationContextManager singleton registration
• Context setting, getting, and clearing
• Rules without context apply to all contexts
• Context-specific rules only apply in matching context
• Array of contexts support
• Fluent API with context restoration
• Variadic parameter extraction for all rule types (ArrayType, In, NotIn, StartsWith, EndsWith, Mimes, etc.)

I'm open to discussions on the naming of things - i'm not 100% convinced myself there :)