MAGETWO-65422: Write default configs to shared configuration file by app:config:dump

Author: Bohdan Korablov

app/code/Magento/Config/etc/di.xml

@@ -183,6 +183,10 @@
     <virtualType name="appDumpSystemSource" type="Magento\Config\App\Config\Source\DumpConfigSourceAggregated">
         <arguments>
             <argument name="sources" xsi:type="array">
+                <item name="modular" xsi:type="array">
+                    <item name="source" xsi:type="object">Magento\Config\App\Config\Source\ModularConfigSource</item>
+                    <item name="sortOrder" xsi:type="string">10</item>
+                </item>
                 <item name="dynamic" xsi:type="array">
                     <item name="source" xsi:type="object">Magento\Config\App\Config\Source\RuntimeConfigSource</item>
                     <item name="sortOrder" xsi:type="string">100</item>

dev/tests/integration/testsuite/Magento/Deploy/Console/Command/App/ApplicationDumpCommandTest.php

@@ -79,6 +79,23 @@ public function setUp()
         // Snapshot of configuration.
         $this->config = $this->loadConfig();
         $this->envConfig = $this->loadEnvConfig();
+
+        $this->writer->saveConfig(
+            [
+                ConfigFilePool::APP_CONFIG => [
+                    'system' => [
+                        'default' => [
+                            'web' => [
+                                'test' => [
+                                    'test_value_3' => 'value from the file'
+                                ]
+                            ]
+                        ]
+                    ]
+                ]
+            ],
+            true
+        );
     }
 
     /**
@@ -197,6 +214,13 @@ private function validateSystemSection(array $config)
         $this->assertArrayNotHasKey('test_sensitive_environment5', $config['system']['default']['web']['test']);
         $this->assertArrayNotHasKey('test_sensitive_environment6', $config['system']['default']['web']['test']);
         $this->assertArrayNotHasKey('test_environment9', $config['system']['default']['web']['test']);
+
+        $this->assertEquals('value from the file', $config['system']['default']['web']['test']['test_value_3']);
+        $this->assertEquals('GB', $config['system']['default']['general']['country']['default']);
+        $this->assertEquals(
+            'HK,IE,MO,PA,GB',
+            $config['system']['default']['general']['country']['optional_zip_countries']
+        );
     }
 
     /**

dev/tests/integration/testsuite/Magento/Deploy/_files/config_data.php

@@ -8,7 +8,9 @@
         '' => [
             'web/test/test_value_1' => 'http://local2.test/',
             'web/test/test_value_2' => 5,
+            'web/test/test_value_3' => 'value from the DB',
             'web/test/test_sensitive' => 10,
+            'general/country/default' => 'GB',
 
             'web/test/test_sensitive1' => 'some_value1',
             'web/test/test_sensitive2' => 'some_value2',