feature symfony#54670 [TypeInfo] Ease getting base type on nullable types (mtarld)

This PR was merged into the 7.1 branch.

Discussion
----------

[TypeInfo] Ease getting base type on nullable types

| Q             | A
| ------------- | ---
| Branch?       | 7.1
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Issues        |
| License       | MIT

Allow retrieving base type on "nullable union types" (ie: `string|null`) without getting a `LogicException`.

Commits
-------

2b73bc9 [TypeInfo] Ease getting base type on nullable types

Author: fabpot

src/Symfony/Component/TypeInfo/Tests/Type/BackedEnumTypeTest.php

@@ -29,6 +29,11 @@ public function testIsNullable()
         $this->assertFalse((new BackedEnumType(DummyBackedEnum::class, Type::int()))->isNullable());
     }
 
+    public function testGetBaseType()
+    {
+        $this->assertEquals(new BackedEnumType(DummyBackedEnum::class, Type::int()), (new BackedEnumType(DummyBackedEnum::class, Type::int()))->getBaseType());
+    }
+
     public function testAsNonNullable()
     {
         $type = new BackedEnumType(DummyBackedEnum::class, Type::int());

src/Symfony/Component/TypeInfo/Tests/Type/BuiltinTypeTest.php

@@ -24,6 +24,11 @@ public function testToString()
         $this->assertSame('int', (string) new BuiltinType(TypeIdentifier::INT));
     }
 
+    public function testGetBaseType()
+    {
+        $this->assertEquals(new BuiltinType(TypeIdentifier::INT), (new BuiltinType(TypeIdentifier::INT))->getBaseType());
+    }
+
     public function testIsNullable()
     {
         $this->assertFalse((new BuiltinType(TypeIdentifier::INT))->isNullable());

src/Symfony/Component/TypeInfo/Tests/Type/CollectionTypeTest.php

@@ -74,6 +74,11 @@ public function testToString()
         $this->assertEquals('array<string,bool>', (string) $type);
     }
 
+    public function testGetBaseType()
+    {
+        $this->assertEquals(Type::int(), Type::collection(Type::generic(Type::int(), Type::string()))->getBaseType());
+    }
+
     public function testIsNullable()
     {
         $this->assertFalse((new CollectionType(Type::generic(Type::builtin(TypeIdentifier::ARRAY), Type::int())))->isNullable());

src/Symfony/Component/TypeInfo/Tests/Type/EnumTypeTest.php

@@ -23,6 +23,11 @@ public function testToString()
         $this->assertSame(DummyEnum::class, (string) new EnumType(DummyEnum::class));
     }
 
+    public function testGetBaseType()
+    {
+        $this->assertEquals(new EnumType(DummyEnum::class), (new EnumType(DummyEnum::class))->getBaseType());
+    }
+
     public function testIsNullable()
     {
         $this->assertFalse((new EnumType(DummyEnum::class))->isNullable());

src/Symfony/Component/TypeInfo/Tests/Type/GenericTypeTest.php

@@ -30,6 +30,11 @@ public function testToString()
         $this->assertEquals(sprintf('%s<bool|string,int,float>', self::class), (string) $type);
     }
 
+    public function testGetBaseType()
+    {
+        $this->assertEquals(Type::object(), Type::generic(Type::object(), Type::int())->getBaseType());
+    }
+
     public function testIsNullable()
     {
         $this->assertFalse((new GenericType(Type::builtin(TypeIdentifier::ARRAY), Type::int()))->isNullable());

src/Symfony/Component/TypeInfo/Tests/Type/IntersectionTypeTest.php

@@ -56,6 +56,12 @@ public function testEveryTypeIs()
         $this->assertFalse($type->everyTypeIs(fn (Type $t) => $t instanceof BuiltinType));
     }
 
+    public function testGetBaseType()
+    {
+        $this->expectException(LogicException::class);
+        (new IntersectionType(Type::string(), Type::int()))->getBaseType();
+    }
+
     public function testToString()
     {
         $type = new IntersectionType(Type::int(), Type::string(), Type::float());

src/Symfony/Component/TypeInfo/Tests/Type/ObjectTypeTest.php

@@ -27,6 +27,11 @@ public function testIsNullable()
         $this->assertFalse((new ObjectType(self::class))->isNullable());
     }
 
+    public function testGetBaseType()
+    {
+        $this->assertEquals(new ObjectType(self::class), (new ObjectType(self::class))->getBaseType());
+    }
+
     public function testIsA()
     {
         $this->assertFalse((new ObjectType(self::class))->isA(TypeIdentifier::ARRAY));

src/Symfony/Component/TypeInfo/Tests/Type/UnionTypeTest.php

@@ -13,6 +13,7 @@
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\TypeInfo\Exception\InvalidArgumentException;
+use Symfony\Component\TypeInfo\Exception\LogicException;
 use Symfony\Component\TypeInfo\Type;
 use Symfony\Component\TypeInfo\Type\BuiltinType;
 use Symfony\Component\TypeInfo\Type\UnionType;
@@ -66,6 +67,14 @@ public function testAsNonNullable()
         ], $type->asNonNullable()->getTypes());
     }
 
+    public function testGetBaseType()
+    {
+        $this->assertEquals(Type::string(), (new UnionType(Type::string(), Type::null()))->getBaseType());
+
+        $this->expectException(LogicException::class);
+        (new UnionType(Type::string(), Type::int(), Type::null()))->getBaseType();
+    }
+
     public function testAtLeastOneTypeIs()
     {
         $type = new UnionType(Type::int(), Type::string(), Type::bool());

src/Symfony/Component/TypeInfo/Tests/TypeTest.php

@@ -57,15 +57,6 @@ public function testIsNullable()
         $this->assertFalse(Type::generic(Type::int(), Type::mixed())->isNullable());
     }
 
-    public function testGetBaseType()
-    {
-        $this->assertEquals(Type::string(), Type::string()->getBaseType());
-        $this->assertEquals(Type::object(self::class), Type::object(self::class)->getBaseType());
-        $this->assertEquals(Type::object(), Type::generic(Type::object(), Type::int())->getBaseType());
-        $this->assertEquals(Type::builtin(TypeIdentifier::ARRAY), Type::list()->getBaseType());
-        $this->assertEquals(Type::int(), Type::collection(Type::generic(Type::int(), Type::string()))->getBaseType());
-    }
-
     public function testCannotGetBaseTypeOnCompoundType()
     {
         $this->expectException(LogicException::class);

src/Symfony/Component/TypeInfo/Type/CompositeTypeTrait.php

@@ -12,7 +12,6 @@
 namespace Symfony\Component\TypeInfo\Type;
 
 use Symfony\Component\TypeInfo\Exception\InvalidArgumentException;
-use Symfony\Component\TypeInfo\Exception\LogicException;
 use Symfony\Component\TypeInfo\Type;
 use Symfony\Component\TypeInfo\TypeIdentifier;
 
@@ -50,11 +49,6 @@ public function __construct(Type ...$types)
         $this->types = array_values(array_unique($types));
     }
 
-    public function getBaseType(): BuiltinType|ObjectType
-    {
-        throw new LogicException(sprintf('Cannot get base type on "%s" compound type.', $this));
-    }
-
     public function isA(TypeIdentifier $typeIdentifier): bool
     {
         return $this->is(fn (Type $type) => $type->isA($typeIdentifier));