Type resolver support

README.md

@@ -116,3 +116,9 @@ This can also be expressed more cleanly as:
   }
 }
 ```
+
+## Advanced
+
+### Resolvers
+
+TODO

src/TypeCreator.php

@@ -37,10 +37,19 @@ public function fields()
     public function getFields()
     {
         $fields = $this->fields();
+        $allFields = [];
 
-        // TODO Field resolution
+        foreach($fields as $name => $field)
+        {
+            $resolver = $this->getFieldResolver($name, $field);
+            if($resolver)
+            {
+                $field['resolve'] = $resolver;
+            }
+            $allFields[$name] = $field;
+        }
 
-        return $fields;
+        return $allFields;
     }
 
     /**
@@ -70,4 +79,24 @@ public function getAttributes()
             ]
         );
     }
+
+    protected function getFieldResolver($name, $field)
+    {
+        $resolveMethod = 'resolve'.ucfirst($name).'Field';
+        if(isset($field['resolve']))
+        {
+            return $field['resolve'];
+        }
+        else if(method_exists($this, $resolveMethod))
+        {
+            $resolver = array($this, $resolveMethod);
+            return function() use ($resolver)
+            {
+                $args = func_get_args();
+                return call_user_func_array($resolver, $args);
+            };
+        }
+
+        return null;
+    }
 }

tests/TypeCreatorTest.php

@@ -9,7 +9,7 @@ class TypeCreatorTest extends SapphireTest
 {
     public function testGetFields()
     {
-        $mock = $this->getMockBuilder('SilverStripe\GraphQL\TypeCreator')
+        $mock = $this->getMockBuilder(TypeCreator::class)
             ->setMethods(['fields'])
             ->getMock();
         $mock->method('fields')->willReturn([
@@ -25,7 +25,7 @@ public function testGetFields()
 
     public function testToArray()
     {
-        $mock = $this->getMockBuilder('SilverStripe\GraphQL\TypeCreator')
+        $mock = $this->getMockBuilder(TypeCreator::class)
             ->setMethods(['fields'])
             ->getMock();
         $mock->method('fields')->willReturn([
@@ -43,7 +43,7 @@ public function testToArray()
 
     public function testGetAttributes()
     {
-        $mock = $this->getMockBuilder('SilverStripe\GraphQL\TypeCreator')
+        $mock = $this->getMockBuilder(TypeCreator::class)
             ->setMethods(['fields'])
             ->getMock();
         $mock->method('fields')->willReturn([
@@ -58,4 +58,52 @@ public function testGetAttributes()
         $fields = $actual['fields']();
         $this->assertArrayHasKey('ID', $fields);
     }
+
+    public function testGetFieldsUsesResolveConfig()
+    {
+        $mock = $this->getMockBuilder(TypeCreator::class)
+            ->setMethods(['fields','resolveFieldAField'])
+            ->getMock();
+        $mock->method('fields')->willReturn([
+            'fieldA' => [
+                'type' => Type::string(),
+                'resolve' => function() {return 'config';},
+            ],
+            'fieldB' => [
+                'type' => Type::string(),
+            ],
+        ]);
+        $mock->method('resolveFieldA')
+            ->willReturn('method');
+
+        $fields = $mock->getFields();
+        $this->assertArrayHasKey('fieldA', $fields);
+        $this->assertArrayHasKey('fieldB', $fields);
+        $this->assertArrayHasKey('resolve', $fields['fieldA']);
+        $this->assertArrayNotHasKey('resolve', $fields['fieldB']);
+        $this->assertEquals('config', $fields['fieldA']['resolve']());
+    }
+
+    public function testGetFieldsUsesResolverMethod()
+    {
+        $mock = $this->getMockBuilder(TypeCreator::class)
+            ->setMethods(['fields','resolveFieldAField'])
+            ->getMock();
+        $mock->method('fields')->willReturn([
+            'fieldA' => [
+                'type' => Type::string(),
+            ],
+            'fieldB' => [
+                'type' => Type::string(),
+            ],
+        ]);
+        $mock->method('resolveFieldA')
+            ->willReturn('resolved');
+
+        $fields = $mock->getFields();
+        $this->assertArrayHasKey('fieldA', $fields);
+        $this->assertArrayHasKey('fieldB', $fields);
+        $this->assertArrayHasKey('resolve', $fields['fieldA']);
+        $this->assertArrayNotHasKey('resolve', $fields['fieldB']);
+    }
 }