Update Psalm and fix issues

composer.json

@@ -39,7 +39,7 @@
     "require-dev": {
         "amphp/php-cs-fixer-config": "^2",
         "phpunit/phpunit": "^9",
-        "psalm/phar": "^5.4"
+        "psalm/phar": "^5.18"
     },
     "autoload": {
         "psr-4": {

psalm.xml

@@ -41,5 +41,11 @@
                 <directory name="src" />
             </errorLevel>
         </MissingClosureReturnType>
+
+        <UnsupportedPropertyReferenceUsage>
+            <errorLevel type="suppress">
+                <directory name="src" />
+            </errorLevel>
+        </UnsupportedPropertyReferenceUsage>
     </issueHandlers>
 </psalm>

src/Closable.php

@@ -13,7 +13,7 @@ public function close(): void;
     /**
      * Returns whether this resource has been closed.
      *
-     * @return bool {@code true} if closed, otherwise {@code false}
+     * @return bool `true` if closed, otherwise `false`.
      */
     public function isClosed(): bool;
 

src/Internal/functions.php

@@ -5,7 +5,15 @@
 /**
  * Formats a stacktrace obtained via `debug_backtrace()`.
  *
- * @param list<array{args?:list<mixed>, class?: class-string, file: string, function: string, line: int, object?: object, type?: string}> $trace
+ * @param list<array{
+ *     args?:list<mixed>,
+ *     class?: class-string,
+ *     file?: string,
+ *     function: string,
+ *     line?: int,
+ *     object?: object,
+ *     type?: string,
+ * }> $trace
  * Output of `debug_backtrace()`.
  *
  * @return string Formatted stacktrace.
@@ -15,10 +23,10 @@
  */
 function formatStacktrace(array $trace): string
 {
-    return \implode("\n", \array_map(static function ($e, $i) {
+    return \implode("\n", \array_map(static function (array $e, int $i): string {
         $line = "#{$i} ";
 
-        if (isset($e["file"])) {
+        if (isset($e["file"], $e['line'])) {
             $line .= "{$e['file']}:{$e['line']} ";
         }
 

src/functions.php

@@ -2,17 +2,16 @@
 
 namespace Amp;
 
-use Amp\Internal\FutureState;
 use Revolt\EventLoop;
 use Revolt\EventLoop\UnsupportedFeatureException;
 
 /**
- * Creates a new fiber asynchronously using the given closure, returning a Future that is completed with the
- * eventual return value of the passed function or will fail if the closure throws an exception.
+ * Creates a new fiber to execute the given closure asynchronously. A Future is returned which is completed with the
+ * return value of the passed closure or will fail if the closure throws an exception.
  *
  * @template T
  *
- * @param \Closure(...):T $closure
+ * @param \Closure(mixed...):T $closure
  * @param mixed ...$args Arguments forwarded to the closure when starting the fiber.
  *
  * @return Future<T>
@@ -21,7 +20,7 @@ function async(\Closure $closure, mixed ...$args): Future
 {
     static $run = null;
 
-    $run ??= static function (FutureState $state, \Closure $closure, array $args): void {
+    $run ??= static function (Internal\FutureState $state, \Closure $closure, array $args): void {
         $s = $state;
         $c = $closure;
 
@@ -37,7 +36,7 @@ function async(\Closure $closure, mixed ...$args): Future
         }
     };
 
-    $state = new Internal\FutureState;
+    $state = new Internal\FutureState();
 
     EventLoop::queue($run, $state, $closure, $args);
 
@@ -156,16 +155,16 @@ function weakClosure(\Closure $closure): \Closure
         $closure = fn (mixed ...$args): mixed => $this->{$method}(...$args);
         if ($useBindTo && $scope) {
             $closure = $closure->bindTo(null, $scope->name);
-
-            if (!$closure) {
-                throw new \RuntimeException('Unable to rebind function to type ' . $scope->name);
-            }
         }
     } else {
         // Rebind to remove reference to $that
         $closure = $closure->bindTo(new \stdClass());
     }
 
+    if (!$closure) {
+        throw new \RuntimeException('Unable to rebind function to type ' . ($scope?->name ?? $that::class));
+    }
+
     $reference = \WeakReference::create($that);
 
     /** @var \Closure(mixed...):TReturn */