Fix Subfilter support

src/Failure/FailureCollection.php

@@ -148,9 +148,15 @@ public function getMessagesForField(string $field): array
         }
 
         $messages = array();
-        foreach ($this[$field] as $failure) {
-            $messages[] = $failure->getMessage();
+
+        if ($this[$field] instanceof FailureCollection) {
+            $messages = $this[$field]->getMessages();
+        } else {
+            foreach ($this[$field] as $failure) {
+                $messages[] = $failure->getMessage();
+            }
         }
+
         return $messages;
     }
 
@@ -193,4 +199,17 @@ public function getMessagesForFieldAsString(string $field, string $prefix = ''):
         }
         return $string;
     }
+
+    public function addSubfieldFailures($field, $spec)
+    {
+        $failure_collection = new FailureCollection();
+
+        foreach ($spec->getMessage() as $f => $messages) {
+            foreach ($messages as $message) {
+                $failure_collection->add($f, $message, $spec->getArgs());
+            }
+        }
+
+        $this[$field] = $failure_collection;
+    }
 }

src/Spec/Spec.php

@@ -277,7 +277,7 @@ public function getField()
      *
      * Returns the failure message for this rule specification.
      *
-     * @return string
+     * @return string|array<string, array<int, string>>
      *
      */
     public function getMessage()

src/Spec/SubSpec.php

@@ -53,7 +53,8 @@ public function __construct(SubjectFilter $filter)
     public function __invoke($subject)
     {
         $field = $this->field;
-        $values =& $subject->$field;
+        $field_values = isset($subject->$field) ? $subject->$field : [];
+        $values =& $field_values;
         return $this->filter->apply($values);
     }
 

src/SubjectFilter.php

@@ -365,19 +365,23 @@ protected function applySpec(Spec $spec, object $subject): bool
      *
      *
      */
-    protected function failed(Spec $spec): Failure
+    protected function failed(Spec $spec)
     {
         $field = $spec->getField();
 
         if ($spec->isHardRule()) {
             $this->skip[$field] = true;
         }
 
-        if (isset($this->field_messages[$field])) {
-            return $this->failures->set($field, $this->field_messages[$field]);
-        }
+        if ($spec instanceof SubSpec) {
+            return $this->failures->addSubfieldFailures($field, $spec);
+        } else {
+            if (isset($this->field_messages[$field])) {
+                return $this->failures->set($field, $this->field_messages[$field]);
+            }
 
-        return $this->failures->add($field, $spec->getMessage(), $spec->getArgs());
+            return $this->failures->add($field, $spec->getMessage(), $spec->getArgs());
+        }
     }
 
     /**

tests/Spec/SubspecTest.php

@@ -0,0 +1,63 @@
+<?php
+namespace Aura\Filter\Spec;
+
+use Aura\Filter\FilterFactory;
+use Yoast\PHPUnitPolyfills\TestCases\TestCase;
+
+class SubspecTest extends TestCase
+{
+    protected $filter;
+
+    protected function set_up()
+    {
+        $filter_factory = new FilterFactory();
+        $this->filter = $filter_factory->newSubjectFilter();
+    }
+
+    public function testMultidimensionalSupport()
+    {
+        $data = [
+            'id' => 'asd',
+            'user' => [
+                'name' => 'Foo',
+                'age' => 'asd',
+            ],
+            // 'url' => 'http://example.com'
+        ];
+
+        $this->filter->validate('id')->is('int');
+        $this->filter->validate('url')->is('url');
+
+        $user_spec = $this->filter->subfilter('user'); // add a "SubSpec"
+        $user_filter = $user_spec->filter();  // Get the "SubSpec" SubjectFilter
+
+        $user_filter->validate('given-name')->isNotBlank();
+        $user_filter->validate('age')->is('int');
+        $user_filter->validate('gender')->is('strlen', 1);
+
+        $subject = (object) $data;
+        $result = $this->filter->apply($subject);
+        $this->assertFalse($result);
+        $expect = [
+            'id' => [
+                'id should have validated as int'
+            ],
+            'url' => [
+                'url should have validated as url',
+            ],
+            'user' => [
+                'given-name' => [
+                    'given-name should not have been blank',
+                ],
+                'age' => [
+                    'age should have validated as int'
+                ],
+                'gender' => [
+                    'gender should have validated as strlen(1)'
+                ]
+            ]
+        ];
+        $actual = $this->filter->getFailures()->getMessages();
+        $this->assertSame($expect, $actual);
+    }
+}