README

PhpTypeCheck is a lightweight PHP library for validating runtime types in arrays and nested data structures.
It helps ensure that incoming data (e.g., from APIs, forms, or dynamic sources) matches expected scalar or object types.

🚀 Features

✅ Validate array elements against scalar or object types
🔁 Support for recursive (nested) arrays
🧩 Validate associative structures with assertStructure()
🔍 Optional keys with key? syntax
🧠 Descriptive error messages with full path and actual/expected types
🧾 Soft validation via checkArrayOfType() and checkStructure()
🧪 Type inspection via describeType()
📤 Structured error output with TypeCheckException::toArray()
🧪 Fully tested with PHPUnit
🎯 Framework-agnostic (works in Symfony, Laravel, Slim, or plain PHP)

📦 Installation

composer require selfphp/php-typecheck

Requirements

PHP >= 8.1
Composer

This library uses modern PHP 8.1 features like readonly properties.

✨ Basic Usage

Validate flat arrays

use Selfphp\PhpTypeCheck\TypeChecker;

TypeChecker::assertArrayOfType([1, 2, 3], 'int');       // ✅ OK
TypeChecker::assertArrayOfType(['a', 'b'], 'string');   // ✅ OK

Validate arrays of objects

TypeChecker::assertArrayOfType([new User(), new User()], User::class); // ✅ OK

Recursive validation

$data = [[1, 2], [3, 4]];
TypeChecker::assertArrayOfType($data, 'int', true); // ✅ OK

Fails with meaningful error

TypeChecker::assertArrayOfType([1, 'two', 3], 'int');
// ❌ Throws TypeCheckException: Element at [1] is of type string, expected int

✅ Soft validation (no exceptions)

`checkArrayOfType()`

if (!TypeChecker::checkArrayOfType([1, 'two'], 'int')) {
    echo "Invalid array values!";
}

`checkStructure()`

$data = ['email' => 'test@example.com'];
$schema = ['email' => 'string', 'phone?' => 'string'];

if (!TypeChecker::checkStructure($data, $schema)) {
    echo "Invalid structure!";
}

🧩 Validate structured arrays

TypeChecker::assertStructure(
    ['name' => 'Alice', 'age' => 30],
    ['name' => 'string', 'age' => 'int']
);

// with nested structures and optional keys
TypeChecker::assertStructure(
    ['profile' => ['city' => 'Berlin'], 'email' => 'a@example.com'],
    ['profile' => ['city' => 'string'], 'email?' => 'string']
);

📤 Structured error reporting

If a TypeCheckException is thrown, you can convert it to a machine-readable format:

try {
    TypeChecker::assertArrayOfType([1, 'x'], 'int');
} catch (TypeCheckException $e) {
    echo json_encode($e->toArray(), JSON_PRETTY_PRINT);
}

{
  "message": "Element at [1] is of type string, expected int",
  "path": "1",
  "expected": "int",
  "actual": "string"
}

🧪 Describe value types

TypeChecker::describeType(42);                         // int
TypeChecker::describeType(['a', 'b']);                 // array<string>
TypeChecker::describeType([1, 'x']);                   // array<int|string>
TypeChecker::describeType([new User(), new User()]);  // array<User>

🛠 Roadmap

assertStructure(array $data, array $schema) for complex key/type validation
checkArrayOfType() and checkStructure() for soft validation
Structured error reporting via toArray()
Type parser support for array<string, User>
Optional integration with static analysis tools (Psalm, PHPStan)

selfphp / php-typecheck

Maintainers

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