Support "true" pseudotypes in native unions

src/Type/ParserNodeTypeToPHPStanType.php

@@ -84,6 +84,8 @@ public static function resolve($type, ?ClassReflection $classReflection): Type
 			return new VoidType();
 		} elseif ($type === 'object') {
 			return new ObjectWithoutClassType();
+		} elseif ($type === 'true') {
+			return new ConstantBooleanType(true);
 		} elseif ($type === 'false') {
 			return new ConstantBooleanType(false);
 		} elseif ($type === 'null') {

src/Type/TypehintHelper.php

@@ -29,6 +29,8 @@ private static function getTypeObjectFromTypehint(string $typeString, ?string $s
 				return new BooleanType();
 			case 'false':
 				return new ConstantBooleanType(false);
+			case 'true':
+				return new ConstantBooleanType(true);
 			case 'string':
 				return new StringType();
 			case 'float':
@@ -118,6 +120,9 @@ public static function decideTypeFromReflection(
 		if (str_ends_with(strtolower($reflectionTypeString), '\\mixed')) {
 			$reflectionTypeString = 'mixed';
 		}
+		if (str_ends_with(strtolower($reflectionTypeString), '\\true')) {
+			$reflectionTypeString = 'true';
+		}
 		if (str_ends_with(strtolower($reflectionTypeString), '\\false')) {
 			$reflectionTypeString = 'false';
 		}

tests/PHPStan/Analyser/NodeScopeResolverTest.php

@@ -982,6 +982,10 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7788.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-7809.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/composer-non-empty-array-after-unset.php');
+
+		if (PHP_VERSION_ID >= 80200) {
+			yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Methods/data/true-typehint.php');
+		}
 		yield from $this->gatherAssertTypes(__DIR__ . '/../Rules/Arrays/data/bug-6000.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/prestashop-breakdowns-empty-array.php');
 

tests/PHPStan/Rules/Functions/ExistingClassesInTypehintsRuleTest.php

@@ -273,4 +273,25 @@ public function testIntersectionTypes(int $phpVersion, array $errors): void
 		$this->analyse([__DIR__ . '/data/intersection-types.php'], $errors);
 	}
 
+	public function dataTrueTypes(): array
+	{
+		return [
+			[
+				80200,
+				[],
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider dataTrueTypes
+	 * @param mixed[] $errors
+	 */
+	public function testTrueTypehint(int $phpVersion, array $errors): void
+	{
+		$this->phpVersionId = $phpVersion;
+
+		$this->analyse([__DIR__ . '/data/true-typehint.php'], $errors);
+	}
+
 }

tests/PHPStan/Rules/Functions/data/true-typehint.php

@@ -0,0 +1,8 @@
+<?php // lint >= 8.2
+
+namespace NativeTrueType;
+
+function alwaysTrue(): true
+{
+	return true;
+}

tests/PHPStan/Rules/Methods/ExistingClassesInTypehintsRuleTest.php

@@ -291,4 +291,22 @@ public function testEnums(): void
 		]);
 	}
 
+	public function dataTrueTypes(): array
+	{
+		return [
+			[80200, []],
+		];
+	}
+
+	/**
+	 * @dataProvider dataTrueTypes
+	 * @param mixed[] $errors
+	 */
+	public function testTrueTypehint(int $phpVersion, array $errors): void
+	{
+		$this->phpVersionId = $phpVersion;
+
+		$this->analyse([__DIR__ . '/data/true-typehint.php'], $errors);
+	}
+
 }

tests/PHPStan/Rules/Methods/data/true-typehint.php

@@ -0,0 +1,44 @@
+<?php // lint >= 8.2
+
+namespace NativeTrueType;
+
+use function PHPStan\Testing\assertType;
+
+class Truthy {
+	public true $truthy = true;
+
+	public function foo(true $v): true {
+		assertType('true', $v);
+	}
+
+	function trueUnion(true|null $trueUnion): void
+	{
+		assertType('true|null', $trueUnion);
+
+		if (is_null($trueUnion)) {
+			assertType('null', $trueUnion);
+			return;
+		}
+
+		if (is_bool($trueUnion)) {
+			assertType('true', $trueUnion);
+			return;
+		}
+
+		assertType('*NEVER*', $trueUnion);
+	}
+
+	function trueUnionReturn(): true|null
+	{
+		if (rand(1, 0)) {
+			return true;
+		}
+		return null;
+	}
+}
+
+function foo(Truthy $truthy) {
+	assertType('true', $truthy->truthy);
+	assertType('true', $truthy->foo(true));
+	assertType('true|null', $truthy->trueUnionReturn());
+}