Reword

Author: javiereguiluz

validation.rst

@@ -801,49 +801,6 @@ You can also validate all the classes stored in a given directory:
 
     $ php bin/console debug:validator src/Entity
 
-Testing Custom Constraints
--------------------------
-
-Since custom constraints contain meaningful logic for your application, writing tests is crucial. You can use the ``ConstraintValidatorTestCase`` to write unit tests for custom constraints:
-
-.. code-block:: php
-    class IsFalseValidatorTest extends ConstraintValidatorTestCase
-    {
-        protected function createValidator()
-        {
-            return new IsFalseValidator();
-        }
-        
-        public function testNullIsValid()
-        {
-            $this->validator->validate(null, new IsFalse());
-
-            $this->assertNoViolation();
-        }
-
-        /**
-         * @dataProvider provideInvalidConstraints
-         */
-        public function testTrueIsInvalid(IsFalse $constraint)
-        {
-            $this->validator->validate(true, $constraint);
-
-            $this->buildViolation('myMessage')
-                ->setParameter('{{ value }}', 'true')
-                ->setCode(IsFalse::NOT_FALSE_ERROR)
-                ->assertRaised();
-        }
-
-        public function provideInvalidConstraints(): iterable
-        {
-            yield 'Doctrine style' => [new IsFalse([
-                'message' => 'myMessage',
-            ])];
-            yield 'named parameters' => [new IsFalse(message: 'myMessage')];
-        }
-        
-    }
-
 Final Thoughts
 --------------
 

validation/custom_constraint.rst

@@ -338,3 +338,46 @@ not to the property:
                 $metadata->addConstraint(new ProtocolClass());
             }
         }
+
+Testing Custom Constraints
+--------------------------
+
+Use the ``ConstraintValidatorTestCase`` utility to simplify the creation of
+unit tests for your custom constraints::
+
+    // ...
+    use App\Validator\ContainsAlphanumeric;
+    use App\Validator\ContainsAlphanumericValidator;
+
+    class ContainsAlphanumericValidatorTest extends ConstraintValidatorTestCase
+    {
+        protected function createValidator()
+        {
+            return new ContainsAlphanumericValidator();
+        }
+
+        public function testNullIsValid()
+        {
+            $this->validator->validate(null, new ContainsAlphanumeric());
+
+            $this->assertNoViolation();
+        }
+
+        /**
+         * @dataProvider provideInvalidConstraints
+         */
+        public function testTrueIsInvalid(ContainsAlphanumeric $constraint)
+        {
+            $this->validator->validate('...', $constraint);
+
+            $this->buildViolation('myMessage')
+                ->setParameter('{{ string }}', '...')
+                ->assertRaised();
+        }
+
+        public function provideInvalidConstraints(): iterable
+        {
+            yield [new ContainsAlphanumeric(message: 'myMessage')];
+            // ...
+        }
+    }