fix(validator): initialize empty constraints

Author: andrepimpao

src/Validator.php

@@ -14,7 +14,7 @@
 class Validator
 {
     /** @var Constraint[] */
-    private array $constraints;
+    private array $constraints = [];
 
     /** @var string[] */
     private static array $namespaces = [];
@@ -106,4 +106,4 @@ public static function setTranslator(?TranslatorInterface $translator): void
     {
         self::$translator = $translator;
     }
-}
+}

tests/ValidatorTest.php

@@ -49,6 +49,14 @@ public function testValidate(): void
         $this->assertCount(0, $violations);
     }
 
+    public function testValidateWithoutConstraints(): void
+    {
+        $violations = (new Validator())->validate('anything');
+
+        $this->assertInstanceOf(ConstraintViolationList::class, $violations);
+        $this->assertCount(0, $violations);
+    }
+
     public function testAssertFail(): void
     {
         $this->expectException(ValidationFailedException::class);
@@ -67,6 +75,11 @@ public function testIsValid(): void
         $this->assertTrue($this->validator->isValid(18));
     }
 
+    public function testIsValidWithoutConstraints(): void
+    {
+        $this->assertTrue((new Validator())->isValid('anything'));
+    }
+
     public function testToArray(): void
     {
         $constraints = $this->validator->toArray();
@@ -76,6 +89,11 @@ public function testToArray(): void
         $this->assertInstanceOf(LessThan::class, $constraints[2]);
     }
 
+    public function testToArrayWithoutConstraints(): void
+    {
+        $this->assertSame([], (new Validator())->toArray());
+    }
+
     public function testCustomConstraint(): void
     {
         Validator::addNamespace('ProgrammatorDev\FluentValidator\Test\Fixtures\Constraint');