Merge pull request #14 from FrontEndCoffee/add-wsdl-caching-to-tax-re…

…solver Add optional CacheInterface to cache VAT rates.
sandwave-io · Mar 13, 2023 · 38c127c · 38c127c
2 parents fa5c42d + aa53a71
commit 38c127c
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Showing 7 changed files with 128 additions and 9 deletions.
diff --git a/README.md b/README.md
@@ -21,9 +21,22 @@ $vatService->validateEuropeanVatNumber("YOURVATNUMBERHERE", "COUNTRYCODE"); // t
 
 $vatService->countryInEurope('NL'); // true
 
-$vatService->europeanVatRate("COUNTRYCODE"); // 0.0
+$vatService->europeanVatRate("YOURVATNUMBERHERE"); // 0.0
 ```
 
+### Caching
+
+If you resolve VAT rates for a country quite often, it can be a little slow. If you want to, you can cache the results
+by passing a `Psr\SimpleCache\CacheInterface` to the `Vat()` service. The implementation might differ based on your 
+application, but all major frameworks implement this interface on their cache.
+
+```php
+/** @var Psr\SimpleCache\CacheInterface $cache */
+
+$vatService = new \SandwaveIo\Vat\Vat(cache: $cache);
+```
+
+
 ## External documentation
 
 * [VIES API](https://ec.europa.eu/taxation_customs/vies/technicalInformation.html)

diff --git a/composer.json b/composer.json
@@ -24,7 +24,8 @@
     "require": {
         "php": "^8.1",
         "ext-soap": "*",
-        "divineomega/php-countries": "^2.3"
+        "divineomega/php-countries": "^2.3",
+        "psr/simple-cache": "^1.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^10.0.15",

diff --git a/src/Vat.php b/src/Vat.php
@@ -3,6 +3,7 @@
 namespace SandwaveIo\Vat;
 
 use DateTimeImmutable;
+use Psr\SimpleCache\CacheInterface;
 use SandwaveIo\Vat\Countries\Iso2;
 use SandwaveIo\Vat\Countries\ResolvesCountries;
 use SandwaveIo\Vat\VatNumbers\ValidatesVatNumbers;
@@ -21,11 +22,15 @@ final class Vat
     public function __construct(
         ?ResolvesCountries $countryResolver = null,
         ?ResolvesVatRates $vatRateResolver = null,
-        ?ValidatesVatNumbers $vatNumberVerifier = null
+        ?ValidatesVatNumbers $vatNumberVerifier = null,
+        ?CacheInterface $cache = null
     ) {
         $this->countryResolver = $countryResolver ?? new Iso2();
         $this->vatRateResolver = $vatRateResolver ?? new TaxesEuropeDatabaseClient();
         $this->vatNumberVerifier = $vatNumberVerifier ?? new ViesClient();
+        if ($cache !== null) {
+            $this->vatRateResolver->setCache($cache);
+        }
     }
 
     public function validateEuropeanVatNumber(string $vatNumber, string $countryCode): bool

diff --git a/src/VatRates/ResolvesVatRates.php b/src/VatRates/ResolvesVatRates.php
@@ -3,8 +3,11 @@
 namespace SandwaveIo\Vat\VatRates;
 
 use DateTimeImmutable;
+use Psr\SimpleCache\CacheInterface;
 
 interface ResolvesVatRates
 {
+    public function setCache(?CacheInterface $cache): void;
+
     public function getDefaultVatRateForCountry(string $countryCode, ?DateTimeImmutable $dateTime = null): ?float;
 }
diff --git a/src/VatRates/TaxesEuropeDatabaseClient.php b/src/VatRates/TaxesEuropeDatabaseClient.php
@@ -3,6 +3,7 @@
 namespace SandwaveIo\Vat\VatRates;
 
 use DateTimeImmutable;
+use Psr\SimpleCache\CacheInterface;
 use SandwaveIo\Vat\Exceptions\VatFetchFailedException;
 use SoapClient;
 use SoapFault;
@@ -15,11 +16,17 @@ final class TaxesEuropeDatabaseClient implements ResolvesVatRates
     const RATE_TYPE_STANDARD = 'STANDARD';
     const RATE_VALUE_TYPE_DEFAULT = 'DEFAULT';
 
-    private ?SoapClient $client;
+    private ?CacheInterface $cache;
 
-    public function __construct(?SoapClient $client = null)
+    public function __construct(private ?SoapClient $client = null)
     {
         $this->client = $client;
+        $this->cache = null;
+    }
+
+    public function setCache(?CacheInterface $cache): void
+    {
+        $this->cache = $cache;
     }
 
     /**
@@ -86,18 +93,36 @@ private function parseRetrieveVatRateResponse(object $response, string $countryC
      */
     private function call(string $call, array $params): ?object
     {
+        $cacheKey = $this->generateCacheKey($call, $params);
+        if ($this->cache !== null && $this->cache->has($cacheKey)) {
+            return $this->cache->get($cacheKey);
+        }
         try {
             $response = $this->getClient()->__soapCall($call, $params);
-            if (! is_object($response)) {
-                return null;
-            }
-            return $response;
         } catch (SoapFault $fault) {
             throw new VatFetchFailedException(
                 'Could not fetch VAT rate from TEDB: ' . $fault->faultstring,
                 $params
             );
         }
+        if (! is_object($response)) {
+            return null;
+        }
+        if ($this->cache !== null) {
+            $this->cache->set($cacheKey, $response);
+        }
+        return $response;
+    }
+
+    /**
+     * @param string                     $call
+     * @param array<string,array<mixed>> $params
+     *
+     * @return string
+     */
+    private function generateCacheKey(string $call, array $params): string
+    {
+        return 'eu_taxes_response_' . md5(serialize(['call' => $call, 'params' => $params]));
     }
 
     private function getClient(): SoapClient

diff --git a/tests/VatRates/TedbClientTest.php b/tests/VatRates/TedbClientTest.php
@@ -6,6 +6,7 @@
 use PHPUnit\Framework\Assert;
 use PHPUnit\Framework\MockObject\MockObject;
 use PHPUnit\Framework\TestCase;
+use Psr\SimpleCache\CacheInterface;
 use SandwaveIo\Vat\Exceptions\VatFetchFailedException;
 use SandwaveIo\Vat\VatRates\TaxesEuropeDatabaseClient;
 use SoapClient;
@@ -48,4 +49,40 @@ public static function soapTestData(): Generator
         yield ['NL', (object) [], null];
         yield ['NL', (object) ['vatRateResults' => []], null];
     }
+
+    public function testWithColdCache(): void
+    {
+        /** @var MockObject&SoapClient $mockedSoapClient */
+        $mockedSoapClient = $this->getMockFromWsdl(TaxesEuropeDatabaseClient::WSDL);
+        $mockedSoapClient
+            ->expects(TestCase::once())
+            ->method('__soapCall')
+            ->with('retrieveVatRates')
+            ->willReturn(unserialize(include 'nl_rates_snapshot.php'));
+
+        $cache = $this->createMock(CacheInterface::class);
+        $cache->expects(TestCase::once())->method('has')->willReturn(false);
+        $cache->expects(TestCase::never())->method('get');
+        $cache->expects(TestCase::once())->method('set');
+
+        $client = new TaxesEuropeDatabaseClient($mockedSoapClient);
+        $client->setCache($cache);
+        $client->getDefaultVatRateForCountry('NL');
+    }
+
+    public function testWithWarmCache(): void
+    {
+        /** @var MockObject&SoapClient $mockedSoapClient */
+        $mockedSoapClient = $this->getMockFromWsdl(TaxesEuropeDatabaseClient::WSDL);
+        $mockedSoapClient->expects(TestCase::never())->method('__soapCall');
+
+        $cache = $this->createMock(CacheInterface::class);
+        $cache->expects(TestCase::once())->method('has')->willReturn(true);
+        $cache->expects(TestCase::once())->method('get')->willReturn(unserialize(include 'nl_rates_snapshot.php'));
+        $cache->expects(TestCase::never())->method('set');
+
+        $client = new TaxesEuropeDatabaseClient($mockedSoapClient);
+        $client->setCache($cache);
+        $client->getDefaultVatRateForCountry('NL');
+    }
 }
diff --git a/tests/VatServiceTest.php b/tests/VatServiceTest.php
@@ -5,6 +5,7 @@
 use Generator;
 use PHPUnit\Framework\Assert;
 use PHPUnit\Framework\TestCase;
+use Psr\SimpleCache\CacheInterface;
 use SandwaveIo\Vat\Countries\ResolvesCountries;
 use SandwaveIo\Vat\Vat;
 use SandwaveIo\Vat\VatNumbers\ValidatesVatNumbers;
@@ -87,4 +88,38 @@ public static function euVatRateTestData(): Generator
         yield ['CA', true, false, null, 0.0];
         yield ['XX', false, false, null, 0.0];
     }
+
+    public function testWithoutCache(): void
+    {
+        $vat = new Vat();
+        // Get Vat::vatRateResolver property.
+        $vatReflection = new \ReflectionClass($vat);
+        $resolverProperty = $vatReflection->getProperty('vatRateResolver');
+        $resolverProperty->setAccessible(true);
+        $resolver = $resolverProperty->getValue($vat);
+        // Get TaxesEuropeDatabaseClient::cache property.
+        $resolverReflection = new \ReflectionClass($resolver);
+        $cacheProperty = $resolverReflection->getProperty('cache');
+        $cacheProperty->setAccessible(true);
+        $cache = $cacheProperty->getValue($resolver);
+
+        Assert::assertNull($cache);
+    }
+
+    public function testWithCache(): void
+    {
+        $vat = new Vat(null, null, null, $this->createStub(CacheInterface::class));
+        // Get Vat::vatRateResolver property.
+        $vatReflection = new \ReflectionClass($vat);
+        $resolverProperty = $vatReflection->getProperty('vatRateResolver');
+        $resolverProperty->setAccessible(true);
+        $resolver = $resolverProperty->getValue($vat);
+        // Get TaxesEuropeDatabaseClient::cache property.
+        $resolverReflection = new \ReflectionClass($resolver);
+        $cacheProperty = $resolverReflection->getProperty('cache');
+        $cacheProperty->setAccessible(true);
+        $cache = $cacheProperty->getValue($resolver);
+
+        Assert::assertInstanceOf(CacheInterface::class, $cache);
+    }
 }