diff --git a/src/DetectChanges/BCBreak/FunctionBased/ParameterNameChanged.php b/src/DetectChanges/BCBreak/FunctionBased/ParameterNameChanged.php
index fab13a8..6b35939 100644
--- a/src/DetectChanges/BCBreak/FunctionBased/ParameterNameChanged.php
+++ b/src/DetectChanges/BCBreak/FunctionBased/ParameterNameChanged.php
@@ -110,17 +110,21 @@ private function compareParameter(ReflectionParameter $fromParameter, Reflection
 
     private function methodHasNoNamedArgumentsAnnotation(ReflectionMethod|ReflectionFunction $function): bool
     {
-        if ($function instanceof ReflectionMethod
+        if (
+            $function instanceof ReflectionMethod
             && str_contains(
                 (string) $function
                     ->getDeclaringClass()
                     ->getDocComment(),
-                self::NO_NAMED_ARGUMENTS_ANNOTATION
+                self::NO_NAMED_ARGUMENTS_ANNOTATION,
             )
         ) {
             return true;
         }
 
-        return str_contains($function->getDocComment(), self::NO_NAMED_ARGUMENTS_ANNOTATION);
+        $comment = $function->getDocComment();
+
+        return $comment !== null
+            && str_contains($comment, self::NO_NAMED_ARGUMENTS_ANNOTATION);
     }
 }
diff --git a/test/unit/DetectChanges/BCBreak/ClassConstantBased/ClassConstantValueChangedTest.php b/test/unit/DetectChanges/BCBreak/ClassConstantBased/ClassConstantValueChangedTest.php
index edbfb63..5b1939c 100644
--- a/test/unit/DetectChanges/BCBreak/ClassConstantBased/ClassConstantValueChangedTest.php
+++ b/test/unit/DetectChanges/BCBreak/ClassConstantBased/ClassConstantValueChangedTest.php
@@ -127,9 +127,9 @@ class TheClass {
             array_map(
                 static fn (string $constant, array $errorMessages): array => [
                     Type\object(ReflectionClassConstant::class)
-                        ->coerce($fromClass->getReflectionConstant($constant)),
+                        ->coerce($fromClass->getConstant($constant)),
                     Type\object(ReflectionClassConstant::class)
-                        ->coerce($toClass->getReflectionConstant($constant)),
+                        ->coerce($toClass->getConstant($constant)),
                     $errorMessages,
                 ],
                 array_keys($properties),
diff --git a/test/unit/DetectChanges/BCBreak/ClassConstantBased/ClassConstantVisibilityReducedTest.php b/test/unit/DetectChanges/BCBreak/ClassConstantBased/ClassConstantVisibilityReducedTest.php
index da921ad..8beeeb8 100644
--- a/test/unit/DetectChanges/BCBreak/ClassConstantBased/ClassConstantVisibilityReducedTest.php
+++ b/test/unit/DetectChanges/BCBreak/ClassConstantBased/ClassConstantVisibilityReducedTest.php
@@ -121,9 +121,9 @@ class TheClass {
             array_map(
                 static fn (string $constant, array $errorMessages): array => [
                     Type\object(ReflectionClassConstant::class)
-                        ->coerce($fromClass->getReflectionConstant($constant)),
+                        ->coerce($fromClass->getConstant($constant)),
                     Type\object(ReflectionClassConstant::class)
-                        ->coerce($toClass->getReflectionConstant($constant)),
+                        ->coerce($toClass->getConstant($constant)),
                     $errorMessages,
                 ],
                 array_keys($properties),
diff --git a/test/unit/DetectChanges/BCBreak/FunctionBased/ParameterByReferenceChangedTest.php b/test/unit/DetectChanges/BCBreak/FunctionBased/ParameterByReferenceChangedTest.php
index aa34aad..b51cc46 100644
--- a/test/unit/DetectChanges/BCBreak/FunctionBased/ParameterByReferenceChangedTest.php
+++ b/test/unit/DetectChanges/BCBreak/FunctionBased/ParameterByReferenceChangedTest.php
@@ -8,6 +8,7 @@
 use Roave\BackwardCompatibility\Change;
 use Roave\BackwardCompatibility\DetectChanges\BCBreak\FunctionBased\ParameterByReferenceChanged;
 use Roave\BetterReflection\BetterReflection;
+use Roave\BetterReflection\Reflection\ReflectionClass;
 use Roave\BetterReflection\Reflection\ReflectionFunction;
 use Roave\BetterReflection\Reflection\ReflectionMethod;
 use Roave\BetterReflection\Reflector\DefaultReflector;
@@ -134,16 +135,16 @@ function changed2(& $a) {}
             ),
             [
                 'N1\C::changed1' => [
-                    $fromReflector->reflectClass('N1\C')->getMethod('changed1'),
-                    $toReflector->reflectClass('N1\C')->getMethod('changed1'),
+                    self::getMethod($fromReflector->reflectClass('N1\C'),'changed1'),
+                    self::getMethod($toReflector->reflectClass('N1\C'), 'changed1'),
                     [
                         '[BC] CHANGED: The parameter $a of N1\C::changed1() changed from by-value to by-reference',
 
                     ],
                 ],
                 'N1\C#changed2'  => [
-                    $fromReflector->reflectClass('N1\C')->getMethod('changed2'),
-                    $toReflector->reflectClass('N1\C')->getMethod('changed2'),
+                    self::getMethod($fromReflector->reflectClass('N1\C'),'changed2'),
+                    self::getMethod($toReflector->reflectClass('N1\C'),'changed2'),
                     [
                         '[BC] CHANGED: The parameter $a of N1\C#changed2() changed from by-value to by-reference',
                     ],
@@ -151,4 +152,14 @@ function changed2(& $a) {}
             ]
         );
     }
+
+    /** @param non-empty-string $name */
+    private static function getMethod(ReflectionClass $class, string $name): ReflectionMethod
+    {
+        $method = $class->getMethod($name);
+
+        \assert($method !== null);
+
+        return $method;
+    }
 }
diff --git a/test/unit/DetectChanges/BCBreak/FunctionBased/ParameterNameChangedTest.php b/test/unit/DetectChanges/BCBreak/FunctionBased/ParameterNameChangedTest.php
index 40a4be2..0c012fd 100644
--- a/test/unit/DetectChanges/BCBreak/FunctionBased/ParameterNameChangedTest.php
+++ b/test/unit/DetectChanges/BCBreak/FunctionBased/ParameterNameChangedTest.php
@@ -16,6 +16,7 @@
 use function array_combine;
 use function array_keys;
 use function array_map;
+use function assert;
 use function iterator_to_array;
 
 /** @covers \Roave\BackwardCompatibility\DetectChanges\BCBreak\FunctionBased\ParameterNameChanged */
@@ -153,6 +154,9 @@ public function theMethod(int $b) {}
         $toClassReflector   = new DefaultReflector($toLocator);
         $fromMethod         = $fromClassReflector->reflectClass('TheClass')->getMethod('theMethod');
         $toMethod           = $toClassReflector->reflectClass('TheClass')->getMethod('theMethod');
+        
+        assert($fromMethod !== null);
+        assert($toMethod !== null);
 
         $changes = (new ParameterNameChanged())($fromMethod, $toMethod);
         self::assertCount(0, $changes);
diff --git a/test/unit/DetectChanges/BCBreak/MethodBased/ExcludeInternalMethodTest.php b/test/unit/DetectChanges/BCBreak/MethodBased/ExcludeInternalMethodTest.php
index ed19e71..97ac797 100644
--- a/test/unit/DetectChanges/BCBreak/MethodBased/ExcludeInternalMethodTest.php
+++ b/test/unit/DetectChanges/BCBreak/MethodBased/ExcludeInternalMethodTest.php
@@ -13,6 +13,8 @@
 use Roave\BetterReflection\Reflector\DefaultReflector;
 use Roave\BetterReflection\SourceLocator\Type\StringSourceLocator;
 
+use function assert;
+
 /** @covers \Roave\BackwardCompatibility\DetectChanges\BCBreak\MethodBased\ExcludeInternalMethod */
 final class ExcludeInternalMethodTest extends TestCase
 {
@@ -32,6 +34,8 @@ function method() {}
             ->reflectClass('A')
             ->getMethod('method');
 
+        assert($method !== null);
+
         $check = $this->createMock(MethodBased::class);
         $check->expects(self::once())
               ->method('__invoke')
@@ -60,6 +64,8 @@ function method() {}
         )))
             ->reflectClass('A')
             ->getMethod('method');
+        
+        assert($method !== null);
 
         $check = $this->createMock(MethodBased::class);
         $check->expects(self::never())
diff --git a/test/unit/DetectChanges/BCBreak/MethodBased/MethodBecameFinalTest.php b/test/unit/DetectChanges/BCBreak/MethodBased/MethodBecameFinalTest.php
index 1d02c23..1d126d0 100644
--- a/test/unit/DetectChanges/BCBreak/MethodBased/MethodBecameFinalTest.php
+++ b/test/unit/DetectChanges/BCBreak/MethodBased/MethodBecameFinalTest.php
@@ -8,6 +8,7 @@
 use Roave\BackwardCompatibility\Change;
 use Roave\BackwardCompatibility\DetectChanges\BCBreak\MethodBased\MethodBecameFinal;
 use Roave\BetterReflection\BetterReflection;
+use Roave\BetterReflection\Reflection\ReflectionClass;
 use Roave\BetterReflection\Reflection\ReflectionMethod;
 use Roave\BetterReflection\Reflector\DefaultReflector;
 use Roave\BetterReflection\SourceLocator\Type\StringSourceLocator;
@@ -15,6 +16,7 @@
 use function array_combine;
 use function array_keys;
 use function array_map;
+use function assert;
 use function iterator_to_array;
 
 /** @covers \Roave\BackwardCompatibility\DetectChanges\BCBreak\MethodBased\MethodBecameFinal */
@@ -124,8 +126,8 @@ private final function privateFinalToFinal() {}
             array_keys($properties),
             array_map(
                 static fn (string $methodName, array $errors): array => [
-                    $fromClass->getMethod($methodName),
-                    $toClass->getMethod($methodName),
+                    self::getMethod($fromClass, $methodName),
+                    self::getMethod($toClass, $methodName),
                     $errors,
                 ],
                 array_keys($properties),
@@ -133,4 +135,14 @@ private final function privateFinalToFinal() {}
             ),
         );
     }
+
+    /** @param non-empty-string $name */
+    private static function getMethod(ReflectionClass $class, string $name): ReflectionMethod
+    {
+        $method = $class->getMethod($name);
+
+        assert($method !== null);
+
+        return $method;
+    }
 }
diff --git a/test/unit/DetectChanges/BCBreak/MethodBased/MethodConcretenessChangedTest.php b/test/unit/DetectChanges/BCBreak/MethodBased/MethodConcretenessChangedTest.php
index 466d2f7..4eba54c 100644
--- a/test/unit/DetectChanges/BCBreak/MethodBased/MethodConcretenessChangedTest.php
+++ b/test/unit/DetectChanges/BCBreak/MethodBased/MethodConcretenessChangedTest.php
@@ -8,6 +8,7 @@
 use Roave\BackwardCompatibility\Change;
 use Roave\BackwardCompatibility\DetectChanges\BCBreak\MethodBased\MethodConcretenessChanged;
 use Roave\BetterReflection\BetterReflection;
+use Roave\BetterReflection\Reflection\ReflectionClass;
 use Roave\BetterReflection\Reflection\ReflectionMethod;
 use Roave\BetterReflection\Reflector\DefaultReflector;
 use Roave\BetterReflection\SourceLocator\Type\StringSourceLocator;
@@ -15,6 +16,7 @@
 use function array_combine;
 use function array_keys;
 use function array_map;
+use function assert;
 use function iterator_to_array;
 
 /** @covers \Roave\BackwardCompatibility\DetectChanges\BCBreak\MethodBased\MethodConcretenessChanged */
@@ -124,8 +126,8 @@ private abstract function privateAbstractToAbstract() {}
             array_keys($properties),
             array_map(
                 static fn (string $methodName, array $errors): array => [
-                    $fromClass->getMethod($methodName),
-                    $toClass->getMethod($methodName),
+                    self::getMethod($fromClass, $methodName),
+                    self::getMethod($toClass, $methodName),
                     $errors,
                 ],
                 array_keys($properties),
@@ -133,4 +135,14 @@ private abstract function privateAbstractToAbstract() {}
             ),
         );
     }
+
+    /** @param non-empty-string $name */
+    private static function getMethod(ReflectionClass $class, string $name): ReflectionMethod
+    {
+        $method = $class->getMethod($name);
+
+        assert($method !== null);
+
+        return $method;
+    }
 }
diff --git a/test/unit/DetectChanges/BCBreak/MethodBased/MethodScopeChangedTest.php b/test/unit/DetectChanges/BCBreak/MethodBased/MethodScopeChangedTest.php
index a6a0b38..73c6b42 100644
--- a/test/unit/DetectChanges/BCBreak/MethodBased/MethodScopeChangedTest.php
+++ b/test/unit/DetectChanges/BCBreak/MethodBased/MethodScopeChangedTest.php
@@ -8,6 +8,7 @@
 use Roave\BackwardCompatibility\Change;
 use Roave\BackwardCompatibility\DetectChanges\BCBreak\MethodBased\MethodScopeChanged;
 use Roave\BetterReflection\BetterReflection;
+use Roave\BetterReflection\Reflection\ReflectionClass;
 use Roave\BetterReflection\Reflection\ReflectionMethod;
 use Roave\BetterReflection\Reflector\DefaultReflector;
 use Roave\BetterReflection\SourceLocator\Type\StringSourceLocator;
@@ -15,6 +16,7 @@
 use function array_combine;
 use function array_keys;
 use function array_map;
+use function assert;
 use function iterator_to_array;
 
 /** @covers \Roave\BackwardCompatibility\DetectChanges\BCBreak\MethodBased\MethodScopeChanged */
@@ -40,10 +42,7 @@ public function testDiffs(
         );
     }
 
-    /**
-     * @return array<string, array<int, ReflectionMethod|array<int, string>>>
-     * @psalm-return array<string, array{0: ReflectionMethod, 1: ReflectionMethod, 2: list<string>}>
-     */
+    /** @return array<string, array{0: ReflectionMethod, 1: ReflectionMethod, 2: list<string>}> */
     public function propertiesToBeTested(): array
     {
         $astLocator = (new BetterReflection())->astLocator();
@@ -124,8 +123,8 @@ private static function privateStaticToStatic() {}
             array_keys($properties),
             array_map(
                 static fn (string $methodName, array $errors): array => [
-                    $fromClass->getMethod($methodName),
-                    $toClass->getMethod($methodName),
+                    self::getMethod($fromClass, $methodName),
+                    self::getMethod($toClass, $methodName),
                     $errors,
                 ],
                 array_keys($properties),
@@ -133,4 +132,14 @@ private static function privateStaticToStatic() {}
             ),
         );
     }
+
+    /** @param non-empty-string $name */
+    private static function getMethod(ReflectionClass $class, string $name): ReflectionMethod
+    {
+        $method = $class->getMethod($name);
+
+        assert($method !== null);
+
+        return $method;
+    }
 }
diff --git a/test/unit/DetectChanges/BCBreak/MethodBased/MethodVisibilityReducedTest.php b/test/unit/DetectChanges/BCBreak/MethodBased/MethodVisibilityReducedTest.php
index 6a6d88d..f4f91b5 100644
--- a/test/unit/DetectChanges/BCBreak/MethodBased/MethodVisibilityReducedTest.php
+++ b/test/unit/DetectChanges/BCBreak/MethodBased/MethodVisibilityReducedTest.php
@@ -8,6 +8,7 @@
 use Roave\BackwardCompatibility\Change;
 use Roave\BackwardCompatibility\DetectChanges\BCBreak\MethodBased\MethodVisibilityReduced;
 use Roave\BetterReflection\BetterReflection;
+use Roave\BetterReflection\Reflection\ReflectionClass;
 use Roave\BetterReflection\Reflection\ReflectionMethod;
 use Roave\BetterReflection\Reflector\DefaultReflector;
 use Roave\BetterReflection\SourceLocator\Type\StringSourceLocator;
@@ -15,6 +16,7 @@
 use function array_combine;
 use function array_keys;
 use function array_map;
+use function assert;
 use function iterator_to_array;
 
 /** @covers \Roave\BackwardCompatibility\DetectChanges\BCBreak\MethodBased\MethodVisibilityReduced */
@@ -110,8 +112,8 @@ public function privateIncreasedToPublic() {}
             array_keys($properties),
             array_map(
                 static fn (string $methodName, array $errors): array => [
-                    $fromClass->getMethod($methodName),
-                    $toClass->getMethod($methodName),
+                    self::getMethod($fromClass, $methodName),
+                    self::getMethod($toClass, $methodName),
                     $errors,
                 ],
                 array_keys($properties),
@@ -119,4 +121,14 @@ public function privateIncreasedToPublic() {}
             ),
         );
     }
+
+    /** @param non-empty-string $name */
+    private static function getMethod(ReflectionClass $class, string $name): ReflectionMethod
+    {
+        $method = $class->getMethod($name);
+
+        assert($method !== null);
+
+        return $method;
+    }
 }
diff --git a/test/unit/Formatter/FunctionNameTest.php b/test/unit/Formatter/FunctionNameTest.php
index e088e92..548cac7 100644
--- a/test/unit/Formatter/FunctionNameTest.php
+++ b/test/unit/Formatter/FunctionNameTest.php
@@ -7,11 +7,14 @@
 use PHPUnit\Framework\TestCase;
 use Roave\BackwardCompatibility\Formatter\FunctionName;
 use Roave\BetterReflection\BetterReflection;
+use Roave\BetterReflection\Reflection\ReflectionClass;
 use Roave\BetterReflection\Reflection\ReflectionFunction;
 use Roave\BetterReflection\Reflection\ReflectionMethod;
 use Roave\BetterReflection\Reflector\DefaultReflector;
 use Roave\BetterReflection\SourceLocator\Type\StringSourceLocator;
 
+use function assert;
+
 /** @covers \Roave\BackwardCompatibility\Formatter\FunctionName */
 final class FunctionNameTest extends TestCase
 {
@@ -64,13 +67,23 @@ function e() {}
                 'N1\b()',
             ],
             'N2\C::d' => [
-                $reflector->reflectClass('N2\C')->getMethod('d'),
+                $this->getMethod($reflector->reflectClass('N2\C'), 'd'),
                 'N2\C::d()',
             ],
             'N2\C#e'  => [
-                $reflector->reflectClass('N2\C')->getMethod('e'),
+                $this->getMethod($reflector->reflectClass('N2\C'), 'e'),
                 'N2\C#e()',
             ],
         ];
     }
+
+    /** @param non-empty-string $name */
+    private function getMethod(ReflectionClass $class, string $name): ReflectionMethod
+    {
+        $method = $class->getMethod($name);
+
+        assert($method !== null);
+
+        return $method;
+    }
 }
diff --git a/test/unit/StringReflectorFactory.php b/test/unit/StringReflectorFactory.php
index 35e3f2e..63f0368 100644
--- a/test/unit/StringReflectorFactory.php
+++ b/test/unit/StringReflectorFactory.php
@@ -7,7 +7,6 @@
 use Roave\BetterReflection\BetterReflection;
 use Roave\BetterReflection\Reflector\DefaultReflector;
 use Roave\BetterReflection\Reflector\Reflector;
-use Roave\BetterReflection\SourceLocator\Exception\EmptyPhpSourceCode;
 use Roave\BetterReflection\SourceLocator\SourceStubber\ReflectionSourceStubber;
 use Roave\BetterReflection\SourceLocator\Type\AggregateSourceLocator;
 use Roave\BetterReflection\SourceLocator\Type\EvaledCodeSourceLocator;
@@ -16,7 +15,7 @@
 
 final class StringReflectorFactory
 {
-    /** @throws EmptyPhpSourceCode */
+    /** @param non-empty-string $sourceCode */
     public function __invoke(string $sourceCode): Reflector
     {
         $astLocator = (new BetterReflection())->astLocator();