test: improve phpunit message for assertInstanceOf

Author: xepozz

composer.json

@@ -58,6 +58,7 @@
     "require-dev": {
         "buggregator/trap": "^1.13.0",
         "composer/composer": "^2.8.4",
+        "cweagans/composer-patches": "^2.0",
         "dereuromark/composer-prefer-lowest": "^0.1.10",
         "doctrine/annotations": "^1.14.4 || ^2.0.2",
         "internal/dload": "^1.2.0",
@@ -103,7 +104,17 @@
         "test:accept": "phpunit --testsuite=Acceptance --color=always --testdox"
     },
     "config": {
-        "sort-packages": true
+        "sort-packages": true,
+        "allow-plugins": {
+            "cweagans/composer-patches": true
+        }
+    },
+    "extra": {
+        "patches": {
+            "phpunit/phpunit": {
+                "Improve assertInstanceOf error message": "patches/phpunit-instance-of.patch"
+            }
+        }
     },
     "minimum-stability": "dev",
     "prefer-stable": true

patches.lock.json

@@ -0,0 +1,17 @@
+{
+    "_hash": "a019c9b721919a9a16ed12424d63d5316cb7d0baf6749363b7aabfa962758213",
+    "patches": {
+        "phpunit/phpunit": [
+            {
+                "package": "phpunit/phpunit",
+                "description": "Improve assertInstanceOf error message",
+                "url": "patches/phpunit-instance-of.patch",
+                "sha256": "4c42249225a057ca528837c8d2642a9fdb7f483991459c9422437b68f0597a70",
+                "depth": 1,
+                "extra": {
+                    "provenance": "root"
+                }
+            }
+        ]
+    }
+}

patches/phpunit-instance-of.patch

@@ -0,0 +1,18 @@
+--- a/src/Framework/Constraint/Type/IsInstanceOf.php
++++ b/src/Framework/Constraint/Type/IsInstanceOf.php
+@@ -74,5 +74,14 @@
+      */
+     protected function failureDescription(mixed $other): string
+     {
+-        return $this->valueToTypeStringFragment($other) . $this->toString(true);
++        $description = $this->valueToTypeStringFragment($other);
++
++        if (\is_object($other)) {
++            $description = \sprintf(
++                'an instance of class %s ',
++                \get_class($other),
++            );
++        }
++
++        return $description . $this->toString();
+     }