Implement typed class constants

RFC: https://wiki.php.net/rfc/typed_class_constants
Co-Authored-By: Ben <[email protected]>
Co-Authored-By: Bob Weinand <[email protected]>

Author: 3 people

Zend/tests/enum/name-property.phpt

@@ -33,14 +33,14 @@ array(1) {
 string(3) "Bar"
 array(2) {
   [0]=>
-  object(ReflectionProperty)#3 (2) {
+  object(ReflectionProperty)#4 (2) {
     ["name"]=>
     string(4) "name"
     ["class"]=>
     string(6) "IntFoo"
   }
   [1]=>
-  object(ReflectionProperty)#4 (2) {
+  object(ReflectionProperty)#5 (2) {
     ["name"]=>
     string(5) "value"
     ["class"]=>

Zend/tests/type_declarations/typed_class_constants_diamond_error1.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Typed class constants (diamond error with self)
+--FILE--
+<?php
+class A {
+    public const self CONST1 = C;
+}
+
+try {
+    define("C", new A());
+} catch (Error $exception) {
+    echo $exception->getMessage() . "\n";
+}
+?>
+--EXPECT--
+Undefined constant "C"

Zend/tests/type_declarations/typed_class_constants_inheritance_error1.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Typed class constants (incompatible inheritance; simple)
+--FILE--
+<?php
+class A {
+    public const int CONST1 = 1;
+}
+
+class B extends A {
+    public const string CONST1 = 'a';
+}
+?>
+--EXPECTF--
+Fatal error: Declaration of B::CONST1 must be compatible with A::CONST1 in %s on line %d

Zend/tests/type_declarations/typed_class_constants_inheritance_error2.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Typed class constants (incompatible inheritance; missing type in child)
+--FILE--
+<?php
+class A {
+    public const int CONST1 = 1;
+}
+
+class B extends A {
+    public const CONST1 = 0;
+}
+?>
+--EXPECTF--
+Fatal error: Declaration of B::CONST1 must be compatible with A::CONST1 in %s on line %d

Zend/tests/type_declarations/typed_class_constants_inheritance_success1.phpt

@@ -0,0 +1,29 @@
+--TEST--
+Typed class constants (inheritance success)
+--FILE--
+<?php
+class A {
+    public const CONST1 = 1;
+    public const CONST2 = 1;
+    public const mixed CONST3 = 1;
+    public const iterable CONST4 = [];
+}
+
+class B extends A {
+    public const int CONST1 = 0;
+    public const mixed CONST2 = 0;
+    public const mixed CONST3 = 0;
+    public const array CONST4 = [];
+}
+
+var_dump(B::CONST1);
+var_dump(B::CONST2);
+var_dump(B::CONST3);
+var_dump(B::CONST4);
+?>
+--EXPECT--
+int(0)
+int(0)
+int(0)
+array(0) {
+}

Zend/tests/type_declarations/typed_class_constants_inheritance_success2.phpt

@@ -0,0 +1,48 @@
+--TEST--
+Typed class constants (inheritance success - object types)
+--FILE--
+<?php
+class S implements Stringable {
+    public function __toString() {
+        return "";
+    }
+}
+
+class Z extends S {}
+
+class A {
+    public const object CONST1 = S;
+    public const S CONST2 = S;
+    public const S|Stringable CONST3 = S;
+    public const S CONST4 = S;
+    public const ?S CONST5 = S;
+}
+
+class B extends A {
+    public const S CONST1 = Z;
+    public const Z CONST2 = Z;
+    public const S CONST3 = Z;
+    public const S&Stringable CONST4 = Z;
+    public const (S&Stringable)|null CONST5 = Z;
+}
+
+define("S", new S());
+define("Z", new Z());
+
+var_dump(B::CONST1);
+var_dump(B::CONST2);
+var_dump(B::CONST3);
+var_dump(B::CONST4);
+var_dump(B::CONST5);
+?>
+--EXPECTF--
+object(Z)#%d (%d) {
+}
+object(Z)#%d (%d) {
+}
+object(Z)#%d (%d) {
+}
+object(Z)#%d (%d) {
+}
+object(Z)#%d (%d) {
+}

Zend/tests/type_declarations/typed_class_constants_inheritance_success3.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Typed class constants (inheritance; private constants)
+--FILE--
+<?php
+class A {
+    private const int CONST1 = 1;
+}
+
+class B extends A {
+    public const string CONST1 = 'a';
+}
+
+var_dump(B::CONST1);
+?>
+--EXPECT--
+string(1) "a"

Zend/tests/type_declarations/typed_class_constants_type_error1.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Typed class constants (type mismatch; simple)
+--FILE--
+<?php
+class A {
+    public const string CONST1 = 1;
+}
+?>
+--EXPECTF--
+Fatal error: Cannot use int as value for class constant A::CONST1 of type string in %s on line %d

Zend/tests/type_declarations/typed_class_constants_type_error2.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Typed class constants (type mismatch; runtime simple)
+--FILE--
+<?php
+class A {
+    public const int CONST1 = C;
+}
+
+define("C", "c");
+
+try {
+    var_dump(A::CONST1);
+} catch (TypeError $exception) {
+    echo $exception->getMessage() . "\n";
+}
+?>
+--EXPECT--
+Cannot assign string to class constant A::CONST1 of type int

Zend/tests/type_declarations/typed_class_constants_type_error3.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Typed class constants (type mismatch; runtime object)
+--FILE--
+<?php
+class A {
+    public const string CONST1 = C;
+}
+
+define('C', new stdClass);
+
+try {
+    var_dump(A::CONST1);
+} catch (TypeError $exception) {
+    echo $exception->getMessage() . "\n";
+}
+?>
+--EXPECT--
+Cannot assign stdClass to class constant A::CONST1 of type string

Zend/tests/type_declarations/typed_class_constants_type_error4.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Typed class constants (type not allowed; callable)
+--FILE--
+<?php
+class A {
+    public const callable CONST1 = 1;
+}
+?>
+--EXPECTF--
+Fatal error: Class constant A::CONST1 cannot have type callable in %s on line %d

Zend/tests/type_declarations/typed_class_constants_type_error5.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Typed class constants (type not allowed; void)
+--FILE--
+<?php
+class A {
+    public const void CONST1 = 1;
+}
+?>
+--EXPECTF--
+Fatal error: Class constant A::CONST1 cannot have type void in %s on line %d

Zend/tests/type_declarations/typed_class_constants_type_error6.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Typed class constants (type not allowed; never)
+--FILE--
+<?php
+class A {
+    public const never CONST1 = 1;
+}
+?>
+--EXPECTF--
+Fatal error: Class constant A::CONST1 cannot have type never in %s on line %d

Zend/tests/type_declarations/typed_class_constants_type_error7.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Typed class constants (type mismatch; runtime)
+--FILE--
+<?php
+class A {
+    public const stdClass&Stringable CONST1 = C;
+}
+
+define("C", new stdClass);
+
+try {
+    var_dump(A::CONST1);
+} catch (TypeError $exception) {
+    echo $exception->getMessage() . "\n";
+}
+?>
+--EXPECT--
+Cannot assign stdClass to class constant A::CONST1 of type stdClass&Stringable

Zend/tests/type_declarations/typed_class_constants_type_error8.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Typed class constants (type not allowed; static)
+--FILE--
+<?php
+class A {
+    public const static CONST1 = C;
+}
+?>
+--EXPECTF--
+Fatal error: Class constant A::CONST1 cannot have type static in %s on line %d

Zend/tests/type_declarations/typed_class_constants_type_success1.phpt

@@ -0,0 +1,43 @@
+--TEST--
+Typed class constants (declaration; compile-type simple)
+--FILE--
+<?php
+class A {
+    public const null CONST1 = null;
+    public const false CONST2 = false;
+    public const true CONST3 = true;
+    public const bool CONST4 = true;
+    public const int CONST5 = 0;
+    public const float CONST6 = 3.14;
+    public const float CONST7 = 3;
+    public const string CONST8 = "";
+    public const array CONST9 = [];
+    public const array|string CONST10 = "";
+    public const array|string|null CONST11 = null;
+}
+
+var_dump(A::CONST1);
+var_dump(A::CONST2);
+var_dump(A::CONST3);
+var_dump(A::CONST4);
+var_dump(A::CONST5);
+var_dump(A::CONST6);
+var_dump(A::CONST7);
+var_dump(A::CONST8);
+var_dump(A::CONST9);
+var_dump(A::CONST10);
+var_dump(A::CONST11);
+?>
+--EXPECT--
+NULL
+bool(false)
+bool(true)
+bool(true)
+int(0)
+float(3.14)
+float(3)
+string(0) ""
+array(0) {
+}
+string(0) ""
+NULL

Zend/tests/type_declarations/typed_class_constants_type_success2.phpt

@@ -0,0 +1,37 @@
+--TEST--
+Typed class constants (declaration; runtime)
+--FILE--
+<?php
+class A {
+    public const object CONST1 = C;
+    public const ?object CONST2 = C;
+    public const B|stdClass CONST3 = C;
+    public const B&Stringable CONST4 = C;
+    public const (B&Stringable)|null CONST5 = C;
+}
+
+class B implements Stringable {
+    public function __toString() {
+        return "";
+    }
+}
+
+const C = new B();
+
+var_dump(A::CONST1);
+var_dump(A::CONST2);
+var_dump(A::CONST3);
+var_dump(A::CONST4);
+var_dump(A::CONST5);
+?>
+--EXPECTF--
+object(B)#%d (%d) {
+}
+object(B)#%d (%d) {
+}
+object(B)#%d (%d) {
+}
+object(B)#%d (%d) {
+}
+object(B)#%d (%d) {
+}

Zend/tests/type_declarations/typed_class_constants_type_success3.phpt

@@ -0,0 +1,23 @@
+--TEST--
+Typed class constants (declaration; enums)
+--FILE--
+<?php
+enum E {
+    const E FooConst = E::Foo;
+
+    case Foo;
+}
+
+class A {
+    public const E CONST1 = E::Foo;
+    public const E CONST2 = E::FooConst;
+}
+
+var_dump(E::FooConst);
+var_dump(A::CONST1);
+var_dump(A::CONST2);
+?>
+--EXPECTF--
+enum(E::Foo)
+enum(E::Foo)
+enum(E::Foo)