From 689b41c555160d894b5e323ba8dcf8c80f29b3a0 Mon Sep 17 00:00:00 2001
From: Martin Seitz <martin.seitz@walls.io>
Date: Tue, 14 Apr 2026 13:19:39 +0200
Subject: [PATCH 1/3] Add tests for NotCallableException::fromInvalidCallable()
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* Tests for circular references
* Tests for `[…, null]` values
---
 tests/Exception/NotCallableExceptionTest.php | 65 ++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 tests/Exception/NotCallableExceptionTest.php

diff --git a/tests/Exception/NotCallableExceptionTest.php b/tests/Exception/NotCallableExceptionTest.php
new file mode 100644
index 0000000..b266a25
--- /dev/null
+++ b/tests/Exception/NotCallableExceptionTest.php
@@ -0,0 +1,65 @@
+<?php declare(strict_types=1);
+
+namespace Invoker\Test\Exception;
+
+use Invoker\Exception\NotCallableException;
+use PHPUnit\Framework\TestCase;
+use stdClass;
+
+class NotCallableExceptionTest extends TestCase
+{
+    /**
+     * @test
+     */
+    #[\PHPUnit\Framework\Attributes\Test]
+    public function handles_object_with_circular_reference()
+    {
+        $obj = new stdClass();
+        $obj->self = $obj;
+
+        $exception = NotCallableException::fromInvalidCallable($obj);
+
+        $this->assertSame('Instance of stdClass is not a callable', $exception->getMessage());
+    }
+
+    /**
+     * @test
+     */
+    #[\PHPUnit\Framework\Attributes\Test]
+    public function handles_array_with_object_and_null_method()
+    {
+        $obj = new stdClass();
+
+        $exception = NotCallableException::fromInvalidCallable([$obj, null]);
+
+        $this->assertSame('stdClass::() is not a callable.', $exception->getMessage());
+    }
+
+    /**
+     * @test
+     */
+    #[\PHPUnit\Framework\Attributes\Test]
+    public function handles_circular_array_reference()
+    {
+        $a = [];
+        $a[] = &$a;
+
+        $exception = NotCallableException::fromInvalidCallable($a);
+
+        $this->assertStringContainsString('is not a callable', $exception->getMessage());
+    }
+
+    /**
+     * @test
+     */
+    #[\PHPUnit\Framework\Attributes\Test]
+    public function handles_circular_array_reference_as_container_entry()
+    {
+        $a = [];
+        $a[] = &$a;
+
+        $exception = NotCallableException::fromInvalidCallable($a, true);
+
+        $this->assertStringContainsString('is neither a callable nor a valid container entry', $exception->getMessage());
+    }
+}

From aa10350c0d10bea5228cb8940c5e9c18954480db Mon Sep 17 00:00:00 2001
From: Martin Seitz <martin.seitz@walls.io>
Date: Tue, 14 Apr 2026 13:20:46 +0200
Subject: [PATCH 2/3] Fix second value entry being null

If the second value entry is null, we should still print the object
error message. `isset()` doesn't match it though.
---
 src/Exception/NotCallableException.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Exception/NotCallableException.php b/src/Exception/NotCallableException.php
index 7f6cb3c..a3389cb 100644
--- a/src/Exception/NotCallableException.php
+++ b/src/Exception/NotCallableException.php
@@ -14,7 +14,7 @@ public static function fromInvalidCallable($value, bool $containerEntry = false)
     {
         if (is_object($value)) {
             $message = sprintf('Instance of %s is not a callable', get_class($value));
-        } elseif (is_array($value) && isset($value[0], $value[1])) {
+        } elseif (is_array($value) && array_key_exists(0, $value) && array_key_exists(1, $value)) {
             $class = is_object($value[0]) ? get_class($value[0]) : $value[0];
 
             $extra = method_exists($class, '__call') || method_exists($class, '__callStatic')

From e19ace320e109a5eecdd2b93be534173ee6f6a66 Mon Sep 17 00:00:00 2001
From: Martin Seitz <martin.seitz@walls.io>
Date: Tue, 14 Apr 2026 13:21:26 +0200
Subject: [PATCH 3/3] Use print_r() instead of var_export()

print_r() handles circular references nicely, but var_export() emits a
warning.
---
 src/Exception/NotCallableException.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Exception/NotCallableException.php b/src/Exception/NotCallableException.php
index a3389cb..ae09e84 100644
--- a/src/Exception/NotCallableException.php
+++ b/src/Exception/NotCallableException.php
@@ -23,9 +23,9 @@ public static function fromInvalidCallable($value, bool $containerEntry = false)
 
             $message = sprintf('%s::%s() is not a callable.%s', $class, $value[1], $extra);
         } elseif ($containerEntry) {
-            $message = var_export($value, true) . ' is neither a callable nor a valid container entry';
+            $message = print_r($value, true) . ' is neither a callable nor a valid container entry';
         } else {
-            $message = var_export($value, true) . ' is not a callable';
+            $message = print_r($value, true) . ' is not a callable';
         }
 
         return new self($message);