Handle instance method callables in initializer type resolution

Author: drewmt

src/Reflection/InitializerExprTypeResolver.php

@@ -938,6 +938,10 @@ public function getFirstClassCallableType(Expr\CallLike $expr, InitializerExprCo
 			);
 		}
 
+		if ($expr instanceof Expr\MethodCall) {
+			return new ObjectType(Closure::class);
+		}
+
 		if ($expr instanceof New_) {
 			return new ErrorType();
 		}

tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php

@@ -1230,6 +1230,21 @@ public function testFirstClassCallables(): void
 		$this->analyse([__DIR__ . '/data/first-class-callables.php'], []);
 	}
 
+	public function testBug15432(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-15432.php'], []);
+	}
+
+	public function testBug15432Invalid(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-15432-invalid.php'], [
+			[
+				'Parameter #1 $callbacks of function Bug15432Invalid\\consume expects array<\'closure\'|\'method\', callable(int): string>, array{method: Closure(string): int, closure: Closure(int): decimal-int-string} given.',
+				23,
+			],
+		]);
+	}
+
 	public function testBug4413(): void
 	{
 		require_once __DIR__ . '/data/bug-4413.php';

tests/PHPStan/Rules/Functions/data/bug-15432-invalid.php

@@ -0,0 +1,27 @@
+<?php // lint >= 8.1
+
+namespace Bug15432Invalid;
+
+/**
+ * @template T of string
+ * @param array<T, callable(int): string> $callbacks
+ */
+function consume(array $callbacks): void
+{
+}
+
+class Handler
+{
+	public function handle(string $value): int
+	{
+		return strlen($value);
+	}
+}
+
+function invalid(Handler $handler): void
+{
+	consume([
+		'method' => $handler->handle(...),
+		'closure' => static fn (int $value): string => (string) $value,
+	]);
+}

tests/PHPStan/Rules/Functions/data/bug-15432.php

@@ -0,0 +1,61 @@
+<?php // lint >= 8.1
+
+namespace Bug15432;
+
+/**
+ * @template T of string
+ * @param array<T, callable(): void> $callbacks
+ */
+function consume(array $callbacks): void
+{
+	foreach ($callbacks as $handler) {
+		$handler();
+	}
+}
+
+consume([
+	'method' => (new class {
+		public function handle(): void {}
+	})->handle(...),
+	'closure' => function (): void {},
+]);
+
+class Handler
+{
+	public function handle(): void {}
+}
+
+function instanceMethods(Handler $handler): void
+{
+	consume([
+		'method' => $handler->handle(...),
+		'closure' => static function (): void {},
+	]);
+	consume([
+		'method' => $handler->handle(...),
+		'closure' => fn () => null,
+	]);
+	$callable = $handler->handle(...);
+	consume([
+		'method' => $callable,
+		'closure' => static function (): void {},
+	]);
+}
+
+/**
+ * @template T of string
+ * @param array<T, array<string, callable(): void>> $callbacks
+ */
+function consumeNested(array $callbacks): void
+{
+}
+
+function nested(Handler $handler): void
+{
+	consumeNested([
+		'callbacks' => [
+			'method' => $handler->handle(...),
+			'closure' => static function (): void {},
+		],
+	]);
+}

turbo-ext/src/InitializerExprTypeResolver.cpp

@@ -4334,6 +4334,12 @@ class InitializerExprTypeResolver
 			return createFirstClassCallable(method.raw(), variants.raw(), nativeTypesPromoted);
 		}
 
+		int isMethodCall = isAClass(expr, PT_CLASS_METHOD_CALL);
+		if (UNEXPECTED(isMethodCall < 0)) return zv::Val();
+		if (isMethodCall) {
+			return newObjectTypeLiteral(PT_LC("Closure"));
+		}
+
 		int isNew = isAClass(expr, PT_CLASS_NEW);
 		if (UNEXPECTED(isNew < 0)) return zv::Val();
 		if (isNew) {