Implement EncryptResolver (#73)

Model/Resolver/EncryptResolver.php

@@ -0,0 +1,64 @@
+<?php
+/**
+ * Copyright © semaio GmbH. All rights reserved.
+ * See LICENSE.md bundled with this module for license details.
+ */
+
+namespace Semaio\ConfigImportExport\Model\Resolver;
+
+use Magento\Framework\Encryption\EncryptorInterface;
+use Semaio\ConfigImportExport\Exception\UnresolveableValueException;
+use function strlen;
+
+class EncryptResolver extends AbstractResolver
+{
+    /**
+     * @var EncryptorInterface
+     */
+    private $encryptor;
+
+    public function __construct(EncryptorInterface $encryptor)
+    {
+        $this->encryptor = $encryptor;
+    }
+
+    /**
+     * Resolve the config value if wrapped with '%encrypt(value)%', this method encrypts the value.
+     *
+     * @param string|null $value
+     * @param string|null $configPath
+     *
+     * @return string|null
+     *
+     * @throws UnresolveableValueException
+     */
+    public function resolve($value, $configPath = null)
+    {
+        if ($value === null) {
+            return null;
+        }
+
+        $value = (string)$value;
+        if ($value === '%encrypt()%') {
+            throw new UnresolveableValueException('Please specify a valid value to encrypt.');
+        }
+
+        $valueToEncrypt = preg_replace_callback(
+            '/\%encrypt\(([^)]+)\)\%/',
+            function ($matches) {
+                return $matches[1];
+            },
+            $value
+        );
+
+        return $this->encryptor->encrypt($valueToEncrypt);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function supports($value, $configPath = null): bool
+    {
+        return 0 === strncmp((string)$value, '%encrypt', strlen('%encrypt'));
+    }
+}

Test/Unit/Model/Resolver/EncryptResolverTest.php

@@ -0,0 +1,112 @@
+<?php
+/**
+ * Copyright © semaio GmbH. All rights reserved.
+ * See LICENSE.md bundled with this module for license details.
+ */
+
+namespace Semaio\ConfigImportExport\Test\Unit\Model\Validator;
+
+use Generator;
+use Magento\Framework\Encryption\EncryptorInterface;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+use Semaio\ConfigImportExport\Exception\UnresolveableValueException;
+use Semaio\ConfigImportExport\Model\Resolver\EncryptResolver;
+use Symfony\Component\Console\Helper\QuestionHelper;
+use Symfony\Component\Console\Input\InputInterface;
+use Symfony\Component\Console\Output\OutputInterface;
+
+class EncryptResolverTest extends TestCase
+{
+    /**
+     * @var InputInterface
+     */
+    private $input;
+
+    /**
+     * @var OutputInterface
+     */
+    private $output;
+
+    /**
+     * @var QuestionHelper
+     */
+    private $questionHelper;
+
+    /**
+     * @var MockObject|EncryptorInterface
+     */
+    private $encryptor;
+
+    /**
+     * Set up test class
+     */
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->input = $this->createMock(InputInterface::class);
+        $this->output = $this->createMock(OutputInterface::class);
+        $this->questionHelper = $this->createMock(QuestionHelper::class);
+        $this->encryptor = $this->createMock(EncryptorInterface::class);
+    }
+
+    /**
+     * @test
+     *
+     * @dataProvider resolveDataProvider
+     */
+    public function validate($value, $expectedResult): void
+    {
+        $this->encryptor->expects($this->any())
+            ->method('encrypt')
+            ->with($expectedResult)
+            ->willReturn($expectedResult);
+
+        $this->assertEquals($this->getEncryptResolver()->resolve($value), $expectedResult);
+    }
+
+    public function resolveDataProvider(): Generator
+    {
+        yield [
+            'test_without_data_to_encrypt',
+            'test_without_data_to_encrypt',
+        ];
+        yield [
+            '%encrypt(data_to_encrypt)%',
+            'data_to_encrypt',
+        ];
+        yield [
+            null,
+            '',
+        ];
+        yield [
+            false,
+            '',
+        ];
+        yield [
+            true,
+            '1',
+        ];
+    }
+
+    public function testItWillRaiseErrorIfEncryptValueIsEmpty(): void
+    {
+        $this->expectException(UnresolveableValueException::class);
+
+        $this->getEncryptResolver()->resolve('%encrypt()%');
+    }
+
+    /**
+     * @return EncryptResolver
+     */
+    private function getEncryptResolver()
+    {
+        $resolver = new EncryptResolver($this->encryptor);
+        $resolver->setInput($this->input);
+        $resolver->setOutput($this->output);
+        $resolver->setQuestionHelper($this->questionHelper);
+
+        return $resolver;
+    }
+}

docs/config-import.md

@@ -87,6 +87,18 @@ vendorx/general/api_key:
 
 You can then set the environment variable `VENDORX_API_KEY` in your CI/CD configuration to the secret API key. 
 
+### Encryption Value Substitution
+
+For importing encrypted configuration data, such as passwords and API keys, into fields utilizing Magento's `\Magento\Config\Model\Config\Backend\Encrypted` backend model, use `%encrypt(value)%` (make sure to put quotes around it) placeholder within your configuration files.
+
+For example, this could be the content of your configuration file:
+
+```
+payment/provider/secret_key:
+  default:
+    0: '%encrypt(mySecretKey)%'
+```
+
 ### Delete Config
 
 Sometimes, it might be helpful to be able to delete certain config values and get back to the default behavior. To do so, your config value has to be a magic-ish string. 

etc/di.xml

@@ -17,6 +17,7 @@
             <argument name="resolvers" xsi:type="array">
                 <item name="environmentVariableResolver" xsi:type="object">Semaio\ConfigImportExport\Model\Resolver\EnvironmentVariableResolver</item>
                 <item name="themePathResolver" xsi:type="object">Semaio\ConfigImportExport\Model\Resolver\ThemePathResolver</item>
+                <item name="encryptResolver" xsi:type="object">Semaio\ConfigImportExport\Model\Resolver\EncryptResolver</item>
             </argument>
         </arguments>
     </type>