allow only strings in form data; throw exception if integer is invali…

…d; allow transformer instances

src/Exception/UnexpectedValueException.php

@@ -0,0 +1,7 @@
+<?php declare(strict_types = 1);
+
+namespace Someniatko\FormTransformer\Exception;
+
+final class UnexpectedValueException extends \UnexpectedValueException
+{
+}

src/FieldTransformer/CallableTransformer.php

@@ -15,7 +15,7 @@ public function __construct(callable $callback, $defaultValue = null)
         $this->defaultValue = $defaultValue;
     }
 
-    public function transformField($formFieldValue)
+    public function transformField(string $formFieldValue)
     {
         return ($this->callback)($formFieldValue);
     }

src/FieldTransformer/CheckboxField.php

@@ -6,10 +6,8 @@
 
 final class CheckboxField implements FieldTransformerInterface
 {
-    public function transformField($formFieldValue)
+    public function transformField(string $formFieldValue)
     {
-        \assert(is_string($formFieldValue));
-
         return $formFieldValue !== '';
     }
 

src/FieldTransformer/IntegerField.php

@@ -2,18 +2,21 @@
 
 namespace Someniatko\FormTransformer\FieldTransformer;
 
+use Someniatko\FormTransformer\Exception\UnexpectedValueException;
 use Someniatko\FormTransformer\FieldTransformerInterface;
 
 final class IntegerField implements FieldTransformerInterface
 {
-    public function transformField($formFieldValue)
+    public function transformField(string $formFieldValue)
     {
-        \assert(is_string($formFieldValue));
         if ($formFieldValue === '') {
             return null;
         }
 
-        \assert(is_numeric($formFieldValue));
+        if (!is_numeric($formFieldValue)) {
+            throw new UnexpectedValueException;
+        }
+
         return (int)$formFieldValue;
     }
 

src/FieldTransformer/StringField.php

@@ -6,9 +6,8 @@
 
 final class StringField implements FieldTransformerInterface
 {
-    public function transformField($formFieldValue)
+    public function transformField(string $formFieldValue)
     {
-        \assert(is_string($formFieldValue));
         return $formFieldValue;
     }
 

src/FieldTransformerInterface.php

@@ -2,14 +2,17 @@
 
 namespace Someniatko\FormTransformer;
 
+use Someniatko\FormTransformer\Exception\UnexpectedValueException;
+
 interface FieldTransformerInterface
 {
     /**
      * Transforms form field value into normalized one
-     * @param mixed $formFieldValue
+     * @param string $formFieldValue
      * @return mixed
+     * @throws UnexpectedValueException
      */
-    public function transformField($formFieldValue);
+    public function transformField(string $formFieldValue);
 
     /**
      * Returns default field normalized value if form data does not contains the field

src/FormDataTransformer.php

@@ -46,6 +46,10 @@ private function createTransformer($configNode) :FieldTransformerInterface
     {
         \assert(!is_array($configNode));
 
+        if ($configNode instanceof FieldTransformerInterface) {
+            return $configNode;
+        }
+
         return is_callable($configNode)
             ? new CallableTransformer($configNode)
             : new $configNode;

src/FormDataTransformerInterface.php

@@ -2,6 +2,8 @@
 
 namespace Someniatko\FormTransformer;
 
+use Someniatko\FormTransformer\Exception\UnexpectedValueException;
+
 interface FormDataTransformerInterface
 {
     /**
@@ -14,6 +16,7 @@ interface FormDataTransformerInterface
      *     field name => FieldTransformer class
      * Fields not specified in the config will be left as is.
      * @return array Normalized data
+     * @throws UnexpectedValueException
      */
     public function transform(array $formData, array $config) :array;
 }

tests/FieldTransformer/IntegerFieldTest.php

@@ -5,7 +5,7 @@
 use PHPUnit\Framework\TestCase;
 use Someniatko\FormTransformer\FieldTransformer\IntegerField;
 
-final class  IntegerFieldTest extends TestCase
+final class IntegerFieldTest extends TestCase
 {
     /**
      * @dataProvider fieldDataProvider
@@ -26,4 +26,10 @@ public function testGetDefaultValue() :void
     {
         $this->assertNull((new IntegerField)->getDefaultValue());
     }
+
+    public function testNonNumericValueResultsInException(): void
+    {
+        $this->expectException(\UnexpectedValueException::class);
+        (new IntegerField)->transformField('abcd');
+    }
 }

tests/FormDataTransformerTest.php

@@ -8,9 +8,9 @@
 
 class BorkTransformer implements FieldTransformerInterface
 {
-    public function transformField($formFieldValue)
+    public function transformField(string $formFieldValue)
     {
-        return $formFieldValue === null ? null : $formFieldValue.'-bork';
+        return $formFieldValue.'-bork';
     }
 
     public function getDefaultValue()
@@ -19,6 +19,26 @@ public function getDefaultValue()
     }
 }
 
+final class TransformerWithConstructor implements FieldTransformerInterface
+{
+    private $addition;
+
+    public function __construct(string $addition)
+    {
+        $this->addition = $addition;
+    }
+
+    public function transformField(string $formFieldValue)
+    {
+        return $formFieldValue.$this->addition;
+    }
+
+    public function getDefaultValue()
+    {
+        return null;
+    }
+}
+
 final class FormDataTransformerTest extends TestCase
 {
     public function testTransformWithoutConfig() :void
@@ -216,4 +236,19 @@ public function testTransformCallableInsideEach() :void
             ],
         ], (new FormDataTransformer)->transform($formData, $config));
     }
+
+    public function testTransformWithTransformerInstance(): void
+    {
+        $formData = [
+            'wolf' => 'boo'
+        ];
+
+        $config = [
+            'wolf' => new TransformerWithConstructor('-bar')
+        ];
+
+        $this->assertEquals([
+            'wolf' => 'boo-bar',
+        ], (new FormDataTransformer)->transform($formData, $config));
+    }
 }