Fix variadic function as callback

.psalm/baseline.xml

@@ -442,7 +442,7 @@
  'arguments_call' => $this->argumentsForCall,
  'return_declaration' => !empty($this->returnType->asString()) ? (': ' . $this->returnType->asString()) : '',
  'return_type' => $this->returnType->asString(),
- 'arguments_count' => !empty($this->argumentsForCall) ? substr_count($this->argumentsForCall, ',') + 1 : 0,
+ 'arguments_count' => $argumentsCount,
  'class_name' => $this->className,
  'method_name' => $this->methodName,
  'modifier' => $this->modifier,

src/Framework/Constraint/Callback.php

@@ -9,6 +9,8 @@
  */
 namespace PHPUnit\Framework\Constraint;
 
+use ReflectionFunction;
+
 /**
  * @psalm-template CallbackInput of mixed
  *
@@ -37,14 +39,32 @@ public function toString(): string
  return 'is accepted by specified callback';
  }
 
+ /**
+ * @psalm-suppress ArgumentTypeCoercion
+ */
+ public function hasVariadicParam(): bool
+ {
+ foreach ((new ReflectionFunction($this->callback))->getParameters() as $parameter) {
+ if ($parameter->isVariadic()) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
  /**
  * Evaluates the constraint for parameter $value. Returns true if the
  * constraint is met, false otherwise.
  *
  * @psalm-param CallbackInput $other
+ *
+ * @psalm-suppress InvalidArgument
  */
  protected function matches(mixed $other): bool
  {
- return ($this->callback)($other);
+ return $this->hasVariadicParam()
+ ? ($this->callback)(...$other)
+ : ($this->callback)($other);
  }
 }

src/Framework/MockObject/Generator/MockMethod.php

@@ -9,6 +9,7 @@
  */
 namespace PHPUnit\Framework\MockObject\Generator;
 
+use const PHP_INT_MAX;
 use function count;
 use function explode;
 use function implode;
@@ -17,6 +18,7 @@
 use function preg_match;
 use function preg_replace;
 use function sprintf;
+use function str_contains;
 use function strlen;
 use function strpos;
 use function substr;
@@ -211,13 +213,21 @@ public function generateCode(): string
 
  $template = $this->loadTemplate($templateFile);
 
+ $argumentsCount = 0;
+
+ if (str_contains($this->argumentsForCall, '...')) {
+ $argumentsCount = PHP_INT_MAX; // @todo: change it to null and update end-to-end tests
+ } elseif (!empty($this->argumentsForCall)) {
+ $argumentsCount = substr_count($this->argumentsForCall, ',') + 1;
+ }
+
  $template->setVar(
  [
  'arguments_decl' => $this->argumentsForDeclaration,
  'arguments_call' => $this->argumentsForCall,
  'return_declaration' => !empty($this->returnType->asString()) ? (': ' . $this->returnType->asString()) : '',
  'return_type' => $this->returnType->asString(),
- 'arguments_count' => !empty($this->argumentsForCall) ? substr_count($this->argumentsForCall, ',') + 1 : 0,
+ 'arguments_count' => $argumentsCount,
  'class_name' => $this->className,
  'method_name' => $this->methodName,
  'modifier' => $this->modifier,

src/Framework/MockObject/Runtime/Rule/Parameters.php

@@ -12,6 +12,7 @@
 use function count;
 use function sprintf;
 use Exception;
+use PHPUnit\Framework\Constraint\Callback;
 use PHPUnit\Framework\Constraint\Constraint;
 use PHPUnit\Framework\Constraint\IsAnything;
 use PHPUnit\Framework\Constraint\IsEqual;
@@ -108,8 +109,13 @@ private function doVerify(): bool
  }
 
  foreach ($this->parameters as $i => $parameter) {
+ if ($parameter instanceof Callback && $parameter->hasVariadicParam()) {
+ $other = $this->invocation->parameters();
+ } else {
+ $other = $this->invocation->parameters()[$i];
+ }
  $parameter->evaluate(
- $this->invocation->parameters()[$i],
+ $other,
  sprintf(
  'Parameter %s for invocation %s does not match expected ' .
  'value.',