Fix WrongNullable false positive

The `nullable` field returned from SignatureTrait::getMethodSignature
is used by DocBlockParamAllowDefaultValueSniff assuming that it means
whether or not the parameter accepts null, so we need to also check if
an explicit null is part of the typehint. This is because in the arrays
returned by File::getMethodParameters, the `nullable_type` field only
indicates if the typehint is prefixed with "?".

Fixes #368.

Author: hemberger

Spryker/Traits/SignatureTrait.php

@@ -57,12 +57,23 @@ protected function getMethodSignature(File $phpCsFile, int $stackPtr): array
                 $typehint = substr($typehint, 1);
             }
 
+            // Determine if parameter accepts null (nullable or explicit null)
+            $nullable = $parameter['nullable_type'];
+            if ($nullable === false && $typehint != '') {
+                for ($i = $parameter['type_hint_token']; $i <= $parameter['type_hint_end_token']; $i++) {
+                    if ($tokens[$i]['code'] === T_NULL) {
+                        $nullable = true;
+                        break;
+                    }
+                }
+            }
+
             $arguments[] = [
                 'variableIndex' => $parameter['token'],
                 'variable' => $parameter['name'],
                 'typehint' => $typehint,
                 'typehintFull' => $parameter['type_hint'],
-                'nullable' => $parameter['nullable_type'],
+                'nullable' => $nullable,
                 'defaultIndex' => $defaultIndex,
                 'default' => $default,
             ];

tests/_data/DocBlockParamAllowDefaultValue/after.php

@@ -67,4 +67,14 @@ public function registerTableMapClass(string $tableMapClass): void
     public function toPHP(mixed $value): mixed {
         return $value;
     }
+
+    /**
+     * This typehint is correct and should not change. See issue #368.
+     *
+     * @param int|string|null $value
+     * @return void
+     */
+    public function multipleUnion(int|string|null $value): void
+    {
+    }
 }

tests/_data/DocBlockParamAllowDefaultValue/before.php

@@ -67,4 +67,14 @@ public function registerTableMapClass(string $tableMapClass): void
     public function toPHP(mixed $value): mixed {
         return $value;
     }
+
+    /**
+     * This typehint is correct and should not change. See issue #368.
+     *
+     * @param int|string|null $value
+     * @return void
+     */
+    public function multipleUnion(int|string|null $value): void
+    {
+    }
 }