Make intersection types nullable

Author: nicolas-grekas

Zend/tests/type_declarations/intersection_types/assigning_intersection_types.phpt

@@ -20,6 +20,9 @@ class A {
     public function method2(X $a): X&Y {
         return new TestParent();
     }
+    public function method3(?X&Y $a): ?X&Y {
+        return $a;
+    }
 }
 
 $tp = new TestParent();
@@ -42,7 +45,10 @@ $r = $o->method1($tc);
 var_dump($r);
 $r = $o->method2($tc);
 var_dump($r);
-
+$r = $o->method3($tc);
+var_dump($r);
+$r = $o->method3(null);
+var_dump($r);
 
 ?>
 --EXPECTF--
@@ -55,3 +61,6 @@ object(TestChild)#%d (0) {
 }
 object(TestParent)#%d (0) {
 }
+object(TestChild)#%d (0) {
+}
+NULL

Zend/tests/type_declarations/intersection_types/bug81268.phpt

@@ -1,5 +1,5 @@
 --TEST--
-Bug #81268 Wrong message when using null as a default value for intersection types
+Bug #81268 Message when using null as a default value for intersection types
 --FILE--
 <?php
 
@@ -9,4 +9,4 @@ class Test {
 
 ?>
 --EXPECTF--
-Fatal error: Cannot use null as default value for property Test::$y of type X&Y in %s on line %d
+Fatal error: Default value for property of type X&Y may not be null. Use the nullable type ?X&Y to allow null default value in %s on line %d

Zend/tests/type_declarations/intersection_types/implicit_nullable_intersection_type.phpt

@@ -1,10 +1,12 @@
 --TEST--
-Intersection types cannot be implicitly nullable
+Intersection types can be implicitly nullable as the others
 --FILE--
 <?php
 
-function foo(X&Y $foo = null) {}
+function foo(X&Y $foo = null) { return $foo; }
+
+var_dump(foo());
 
 ?>
---EXPECTF--
-Fatal error: Cannot use null as default value for parameter $foo of type X&Y in %s on line %d
+--EXPECT--
+NULL

Zend/tests/type_declarations/intersection_types/invalid_types/invalid_nullable_type.phpt

@@ -9,10 +9,11 @@ interface B {}
 class Foo implements A, B {}
 class Bar implements A {}
 
-function foo(A&B $bar) {
+function foo(?A&B $bar) {
     var_dump($bar);
 }
 
+foo(null);
 foo(new Foo());
 
 try {
@@ -23,6 +24,7 @@ try {
 
 ?>
 --EXPECTF--
+NULL
 object(Foo)#1 (0) {
 }
-foo(): Argument #1 ($bar) must be of type A&B, Bar given, called in %s on line %d
+foo(): Argument #1 ($bar) must be of type ?A&B, Bar given, called in %s on line %d

Zend/tests/type_declarations/intersection_types/parameter.phpt

@@ -0,0 +1,31 @@
+--TEST--
+Intersection types and typed reference
+--FILE--
+<?php
+
+interface X {}
+interface Y {}
+interface Z {}
+
+class A implements X, Y, Z {}
+class B implements X, Y {}
+
+class Test {
+    public ?X&Y $y;
+    public X&Z $z;
+}
+$test = new Test;
+$r = new A;
+$test->y =& $r;
+$test->z =& $r;
+
+
+try {
+    $r = null;
+} catch (\TypeError $e) {
+    echo $e->getMessage(), \PHP_EOL;
+}
+
+?>
+--EXPECT--
+Cannot assign null to reference held by property Test::$z of type X&Z

Zend/tests/type_declarations/intersection_types/typed_reference2.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Intersection types and typed reference
+--FILE--
+<?php
+
+interface X {}
+interface Y {}
+interface Z {}
+
+class A implements X, Y, Z {}
+class B implements X, Y {}
+
+class Test {
+    public ?X&Y $y;
+    public ?X&Z $z;
+}
+$test = new Test;
+$r = new A;
+$test->y =& $r;
+$test->z =& $r;
+
+$r = null;
+
+?>
+==DONE==
+--EXPECT--
+==DONE==

Zend/tests/type_declarations/intersection_types/typed_reference3.phpt

@@ -0,0 +1,32 @@
+--TEST--
+Invalid nullable widening
+--FILE--
+<?php
+
+interface A {}
+interface B {}
+interface C {}
+
+class Test implements A, B, C {}
+
+class Foo {
+    public function foo(): A {
+        return new Test();
+    }
+}
+
+class FooChild extends Foo {
+    public function foo(): A&B {
+        return new Test();
+    }
+}
+
+class FooSecondChild extends FooChild {
+    public function foo(): ?A&B {
+        return new Test();
+    }
+}
+
+?>
+--EXPECTF--
+Fatal error: Declaration of FooSecondChild::foo(): ?A&B must be compatible with FooChild::foo(): A&B in %s on line %d

Zend/tests/type_declarations/intersection_types/variance/invalid7.phpt

@@ -0,0 +1,18 @@
+--TEST--
+Intersection type removing nullable
+--FILE--
+<?php
+
+class A {}
+class B extends A {}
+
+class Test {
+    public ?A&B $prop;
+}
+class Test2 extends Test {
+    public A&B $prop;
+}
+
+?>
+--EXPECTF--
+Fatal error: Type of Test2::$prop must be ?A&B (as in class Test) in %s on line %d

Zend/tests/type_declarations/intersection_types/variance/invalid8.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Invalid nullable narrowing
+--FILE--
+<?php
+
+interface A {}
+interface B {}
+
+class Foo {
+    public function foo(?A&B $foo) {
+    }
+}
+
+class FooChild extends Foo {
+    public function foo(A&B $foo) {
+    }
+}
+
+?>
+--EXPECTF--
+Fatal error: Declaration of FooChild::foo(A&B $foo) must be compatible with Foo::foo(?A&B $foo) in %s on line %d