Interfaces can have properties

src/PhpGenerator/ClassManipulator.php

@@ -25,25 +25,28 @@ public function __construct(
 	 */
 	public function inheritProperty(string $name, bool $returnIfExists = false): Property
 	{
-		$extends = $this->class->getExtends();
 		if ($this->class->hasProperty($name)) {
 			return $returnIfExists
 				? $this->class->getProperty($name)
 				: throw new Nette\InvalidStateException("Cannot inherit property '$name', because it already exists.");
-
-		} elseif (!$extends) {
-			throw new Nette\InvalidStateException("Class '{$this->class->getName()}' has not setExtends() set.");
 		}
 
-		try {
-			$rp = new \ReflectionProperty($extends, $name);
-		} catch (\ReflectionException) {
-			throw new Nette\InvalidStateException("Property '$name' has not been found in ancestor {$extends}");
+		$parents = [...(array) $this->class->getExtends(), ...$this->class->getImplements()]
+			?: throw new Nette\InvalidStateException("Class '{$this->class->getName()}' has neither setExtends() nor setImplements() set.");
+
+		foreach ($parents as $parent) {
+			try {
+				$rp = new \ReflectionProperty($parent, $name);
+			} catch (\ReflectionException) {
+				continue;
+			}
+			$property = (new Factory)->fromPropertyReflection($rp);
+			$this->class->addMember($property);
+			$property->setHooks([]);
+			return $property;
 		}
 
-		$property = (new Factory)->fromPropertyReflection($rp);
-		$this->class->addMember($property);
-		return $property;
+		throw new Nette\InvalidStateException("Property '$name' has not been found in any ancestor: " . implode(', ', $parents));
 	}
 
 
@@ -52,16 +55,15 @@ public function inheritProperty(string $name, bool $returnIfExists = false): Pro
 	 */
 	public function inheritMethod(string $name, bool $returnIfExists = false): Method
 	{
-		$parents = [...(array) $this->class->getExtends(), ...$this->class->getImplements()];
 		if ($this->class->hasMethod($name)) {
 			return $returnIfExists
 				? $this->class->getMethod($name)
 				: throw new Nette\InvalidStateException("Cannot inherit method '$name', because it already exists.");
-
-		} elseif (!$parents) {
-			throw new Nette\InvalidStateException("Class '{$this->class->getName()}' has neither setExtends() nor setImplements() set.");
 		}
 
+		$parents = [...(array) $this->class->getExtends(), ...$this->class->getImplements()]
+			?: throw new Nette\InvalidStateException("Class '{$this->class->getName()}' has neither setExtends() nor setImplements() set.");
+
 		foreach ($parents as $parent) {
 			try {
 				$rm = new \ReflectionMethod($parent, $name);
@@ -91,5 +93,8 @@ public function implementInterface(string $interfaceName): void
 		foreach ($interface->getMethods() as $method) {
 			$this->inheritMethod($method->getName(), returnIfExists: true);
 		}
+		foreach ($interface->getProperties() as $property) {
+			$this->inheritProperty($property->getName(), returnIfExists: true);
+		}
 	}
 }

src/PhpGenerator/InterfaceType.php

@@ -19,6 +19,7 @@ final class InterfaceType extends ClassLike
 {
 	use Traits\ConstantsAware;
 	use Traits\MethodsAware;
+	use Traits\PropertiesAware;
 
 	/** @var string[] */
 	private array $extends = [];
@@ -54,12 +55,13 @@ public function addExtend(string $name): static
 	/**
 	 * Adds a member. If it already exists, throws an exception or overwrites it if $overwrite is true.
 	 */
-	public function addMember(Method|Constant $member, bool $overwrite = false): static
+	public function addMember(Method|Constant|Property $member, bool $overwrite = false): static
 	{
 		$name = $member->getName();
 		[$type, $n] = match (true) {
 			$member instanceof Constant => ['consts', $name],
 			$member instanceof Method => ['methods', strtolower($name)],
+			$member instanceof Property => ['properties', $name],
 		};
 		if (!$overwrite && isset($this->$type[$n])) {
 			throw new Nette\InvalidStateException("Cannot add member '$name', because it already exists.");
@@ -69,11 +71,25 @@ public function addMember(Method|Constant $member, bool $overwrite = false): sta
 	}
 
 
+	/** @throws Nette\InvalidStateException */
+	public function validate(): void
+	{
+		foreach ($this->getProperties() as $property) {
+			if ($property->isInitialized()) {
+				throw new Nette\InvalidStateException("Property {$this->getName()}::\${$property->getName()}: Interface cannot have initialized properties.");
+			} elseif (!$property->getHooks()) {
+				throw new Nette\InvalidStateException("Property {$this->getName()}::\${$property->getName()}: Interface cannot have properties without hooks.");
+			}
+		}
+	}
+
+
 	public function __clone(): void
 	{
 		parent::__clone();
 		$clone = fn($item) => clone $item;
 		$this->consts = array_map($clone, $this->consts);
 		$this->methods = array_map($clone, $this->methods);
+		$this->properties = array_map($clone, $this->properties);
 	}
 }

src/PhpGenerator/Printer.php

@@ -198,9 +198,9 @@ public function printClass(
 		}
 
 		$properties = [];
-		if ($class instanceof ClassType || $class instanceof TraitType) {
+		if ($class instanceof ClassType || $class instanceof TraitType || $class instanceof InterfaceType) {
 			foreach ($class->getProperties() as $property) {
-				$properties[] = $this->printProperty($property, $readOnlyClass);
+				$properties[] = $this->printProperty($property, $readOnlyClass, $class instanceof InterfaceType);
 			}
 		}
 
@@ -376,7 +376,7 @@ private function printConstant(Constant $const): string
 	}
 
 
-	private function printProperty(Property $property, bool $readOnlyClass = false): string
+	private function printProperty(Property $property, bool $readOnlyClass = false, bool $isInterface = false): string
 	{
 		$property->validate();
 		$type = $property->getType();
@@ -395,7 +395,7 @@ private function printProperty(Property $property, bool $readOnlyClass = false):
 			. $this->printAttributes($property->getAttributes())
 			. $def
 			. $defaultValue
-			. ($this->printHooks($property) ?: ';')
+			. ($this->printHooks($property, $isInterface) ?: ';')
 			. "\n";
 	}
 
@@ -456,27 +456,34 @@ protected function printAttributes(array $attrs, bool $inline = false): string
 	}
 
 
-	private function printHooks(Property|PromotedParameter $property): string
+	private function printHooks(Property|PromotedParameter $property, bool $isInterface = false): string
 	{
 		$hooks = $property->getHooks();
 		if (!$hooks) {
 			return '';
 		}
 
+		$simple = true;
 		foreach ($property->getHooks() as $type => $hook) {
+			$simple = $simple && ($hook->isAbstract() || $isInterface);
 			$hooks[$type] = $this->printDocComment($hook)
 				. $this->printAttributes($hook->getAttributes())
-				. ($hook->isFinal() ? 'final ' : '')
-				. ($hook->getReturnReference() ? '&' : '')
-				. $type
-				. ($hook->getParameters() ? $this->printParameters($hook) : '')
-				. ' '
-				. ($hook->isShort()
-					? '=> ' . $hook->getBody() . ';'
-					: "{\n" . $this->indent($this->printFunctionBody($hook)) . '}');
+				. ($hook->isAbstract() || $isInterface
+					? ($hook->getReturnReference() ? '&' : '')
+						. $type . ';'
+					: ($hook->isFinal() ? 'final ' : '')
+						. ($hook->getReturnReference() ? '&' : '')
+						. $type
+						. ($hook->getParameters() ? $this->printParameters($hook) : '')
+						. ' '
+						. ($hook->isShort()
+							? '=> ' . $hook->getBody() . ';'
+							: "{\n" . $this->indent($this->printFunctionBody($hook)) . '}'));
 		}
 
-		return " {\n" . $this->indent(implode("\n", $hooks)) . "\n}";
+		return $simple
+			? ' { ' . implode(' ', $hooks) . ' }'
+			: " {\n" . $this->indent(implode("\n", $hooks)) . "\n}";
 	}
 
 

src/PhpGenerator/PropertyHook.php

@@ -15,6 +15,7 @@ class PropertyHook
 	private string $body = '';
 	private bool $short = false;
 	private bool $final = false;
+	private bool $abstract = false;
 
 	/** @var Parameter[] */
 	private array $parameters = [];
@@ -62,6 +63,19 @@ public function isFinal(): bool
 	}
 
 
+	public function setAbstract(bool $state = true): static
+	{
+		$this->abstract = $state;
+		return $this;
+	}
+
+
+	public function isAbstract(): bool
+	{
+		return $this->abstract;
+	}
+
+
 	/** @internal */
 	public function setParameters(array $val): static
 	{

tests/PhpGenerator/ClassManipulator.implementInterface.84.phpt

@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * @phpVersion 8.4
+ */
+
+declare(strict_types=1);
+
+use Nette\PhpGenerator\ClassManipulator;
+use Nette\PhpGenerator\ClassType;
+use Tester\Assert;
+
+require __DIR__ . '/../bootstrap.php';
+
+
+interface TestInterface
+{
+	public array $bar { get; }
+
+	public function testMethod();
+}
+
+$class = new ClassType('TestClass');
+$manipulator = new ClassManipulator($class);
+
+// Test valid interface implementation
+$manipulator->implementInterface(TestInterface::class);
+Assert::match(<<<'XX'
+	class TestClass implements TestInterface
+	{
+		public array $bar;
+
+
+		function testMethod()
+		{
+		}
+	}
+
+	XX, (string) $class);
+
+
+// Test exception for non-interface
+Assert::exception(
+	fn() => $manipulator->implementInterface(stdClass::class),
+	InvalidArgumentException::class,
+);

tests/PhpGenerator/ClassManipulator.implementInterface.phpt

@@ -19,8 +19,16 @@ $manipulator = new ClassManipulator($class);
 
 // Test valid interface implementation
 $manipulator->implementInterface(TestInterface::class);
-Assert::true(in_array(TestInterface::class, $class->getImplements(), true));
-Assert::true($class->hasMethod('testMethod'));
+Assert::match(<<<'XX'
+	class TestClass implements TestInterface
+	{
+		function testMethod()
+		{
+		}
+	}
+
+	XX, (string) $class);
+
 
 // Test exception for non-interface
 Assert::exception(

tests/PhpGenerator/ClassManipulator.inheritProperty.phpt

@@ -21,14 +21,14 @@ $manipulator = new ClassManipulator($class);
 Assert::exception(
 	fn() => $manipulator->inheritProperty('bar'),
 	Nette\InvalidStateException::class,
-	"Class 'Test' has not setExtends() set.",
+	"Class 'Test' has neither setExtends() nor setImplements() set.",
 );
 
 $class->setExtends('Unknown');
 Assert::exception(
 	fn() => $manipulator->inheritProperty('bar'),
 	Nette\InvalidStateException::class,
-	"Property 'bar' has not been found in ancestor Unknown",
+	"Property 'bar' has not been found in any ancestor: Unknown",
 );
 
 

tests/PhpGenerator/InterfaceType.validate.phpt

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+use Nette\PhpGenerator\InterfaceType;
+use Tester\Assert;
+
+require __DIR__ . '/../bootstrap.php';
+
+
+Assert::exception(function () {
+	$interface = new InterfaceType('Demo');
+	$interface->addProperty('first', 123);
+	$interface->validate();
+}, Nette\InvalidStateException::class, 'Property Demo::$first: Interface cannot have initialized properties.');
+
+Assert::exception(function () {
+	$interface = new InterfaceType('Demo');
+	$interface->addProperty('first');
+	$interface->validate();
+}, Nette\InvalidStateException::class, 'Property Demo::$first: Interface cannot have properties without hooks.');

tests/PhpGenerator/PropertyLike.hooks.phpt

@@ -7,6 +7,7 @@
 declare(strict_types=1);
 
 use Nette\PhpGenerator\ClassType;
+use Nette\PhpGenerator\InterfaceType;
 
 require __DIR__ . '/../bootstrap.php';
 
@@ -96,3 +97,27 @@ same(<<<'XX'
 	}
 
 	XX, (string) $class);
+
+
+$interface = new InterfaceType('Demo');
+
+$interface->addProperty('first')
+	->setType('int')
+	->setPublic()
+	->addHook('get');
+
+$prop = $interface->addProperty('second')
+	->setType('Value')
+	->setPublic();
+
+$prop->addHook('get');
+$prop->addHook('set');
+
+same(<<<'XX'
+	interface Demo
+	{
+		public int $first { get; }
+		public Value $second { set; get; }
+	}
+
+	XX, (string) $interface);