Short code lengths can now be customized

config/autoload/url-shortener.global.php

@@ -2,6 +2,8 @@
 
 declare(strict_types=1);
 
+use const Shlinkio\Shlink\Core\DEFAULT_SHORT_CODES_LENGTH;
+
 return [
 
     'url_shortener' => [
@@ -11,6 +13,7 @@ return [
         ],
         'validate_url' => false,
         'visits_webhooks' => [],
+        'default_short_codes_length' => DEFAULT_SHORT_CODES_LENGTH,
     ],
 
 ];

module/Core/functions/functions.php

@@ -10,7 +10,9 @@ use PUGX\Shortid\Factory as ShortIdFactory;
 
 use function sprintf;
 
-function generateRandomShortCode(int $length = 5): string
+const DEFAULT_SHORT_CODES_LENGTH = 5;
+
+function generateRandomShortCode(int $length): string
 {
     static $shortIdFactory;
     if ($shortIdFactory === null) {

module/Core/src/Entity/ShortUrl.php

@@ -34,6 +34,7 @@ class ShortUrl extends AbstractEntity
     private ?int $maxVisits = null;
     private ?Domain $domain;
     private bool $customSlugWasProvided;
+    private int $shortCodeLength;
 
     public function __construct(
         string $longUrl,
@@ -50,7 +51,8 @@ class ShortUrl extends AbstractEntity
         $this->validUntil = $meta->getValidUntil();
         $this->maxVisits = $meta->getMaxVisits();
         $this->customSlugWasProvided = $meta->hasCustomSlug();
-        $this->shortCode = $meta->getCustomSlug() ?? generateRandomShortCode();
+        $this->shortCodeLength = $meta->getShortCodeLength();
+        $this->shortCode = $meta->getCustomSlug() ?? generateRandomShortCode($this->shortCodeLength);
         $this->domain = ($domainResolver ?? new SimpleDomainResolver())->resolveDomain($meta->getDomain());
     }
 
@@ -119,7 +121,7 @@ class ShortUrl extends AbstractEntity
             throw ShortCodeCannotBeRegeneratedException::forShortUrlAlreadyPersisted();
         }
 
-        $this->shortCode = generateRandomShortCode();
+        $this->shortCode = generateRandomShortCode($this->shortCodeLength);
         return $this;
     }
 

module/Core/src/Model/ShortUrlMeta.php

@@ -11,6 +11,8 @@ use Shlinkio\Shlink\Core\Validation\ShortUrlMetaInputFilter;
 use function array_key_exists;
 use function Shlinkio\Shlink\Core\parseDateField;
 
+use const Shlinkio\Shlink\Core\DEFAULT_SHORT_CODES_LENGTH;
+
 final class ShortUrlMeta
 {
     private bool $validSincePropWasProvided = false;
@@ -22,6 +24,7 @@ final class ShortUrlMeta
     private ?int $maxVisits = null;
     private ?bool $findIfExists = null;
     private ?string $domain = null;
+    private int $shortCodeLength = 5;
 
     // Force named constructors
     private function __construct()
@@ -58,11 +61,20 @@ final class ShortUrlMeta
         $this->validUntil = parseDateField($inputFilter->getValue(ShortUrlMetaInputFilter::VALID_UNTIL));
         $this->validUntilPropWasProvided = array_key_exists(ShortUrlMetaInputFilter::VALID_UNTIL, $data);
         $this->customSlug = $inputFilter->getValue(ShortUrlMetaInputFilter::CUSTOM_SLUG);
-        $maxVisits = $inputFilter->getValue(ShortUrlMetaInputFilter::MAX_VISITS);
-        $this->maxVisits = $maxVisits !== null ? (int) $maxVisits : null;
+        $this->maxVisits = $this->getOptionalIntFromInputFilter($inputFilter, ShortUrlMetaInputFilter::MAX_VISITS);
         $this->maxVisitsPropWasProvided = array_key_exists(ShortUrlMetaInputFilter::MAX_VISITS, $data);
         $this->findIfExists = $inputFilter->getValue(ShortUrlMetaInputFilter::FIND_IF_EXISTS);
         $this->domain = $inputFilter->getValue(ShortUrlMetaInputFilter::DOMAIN);
+        $this->shortCodeLength = $this->getOptionalIntFromInputFilter(
+            $inputFilter,
+            ShortUrlMetaInputFilter::SHORT_CODE_LENGTH,
+        ) ?? DEFAULT_SHORT_CODES_LENGTH;
+    }
+
+    private function getOptionalIntFromInputFilter(ShortUrlMetaInputFilter $inputFilter, string $fieldName): ?int
+    {
+        $value = $inputFilter->getValue($fieldName);
+        return $value !== null ? (int) $value : null;
     }
 
     public function getValidSince(): ?Chronos
@@ -119,4 +131,9 @@ final class ShortUrlMeta
     {
         return $this->domain;
     }
+
+    public function getShortCodeLength(): int
+    {
+        return $this->shortCodeLength;
+    }
 }

module/Core/src/Validation/ShortUrlMetaInputFilter.php

@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace Shlinkio\Shlink\Core\Validation;
 
 use DateTime;
+use Laminas\InputFilter\Input;
 use Laminas\InputFilter\InputFilter;
 use Laminas\Validator;
 use Shlinkio\Shlink\Common\Validation;
@@ -19,6 +20,7 @@ class ShortUrlMetaInputFilter extends InputFilter
     public const MAX_VISITS = 'maxVisits';
     public const FIND_IF_EXISTS = 'findIfExists';
     public const DOMAIN = 'domain';
+    public const SHORT_CODE_LENGTH = 'shortCodeLength';
 
     public function __construct(array $data)
     {
@@ -40,10 +42,8 @@ class ShortUrlMetaInputFilter extends InputFilter
         $customSlug->getFilterChain()->attach(new Validation\SluggerFilter());
         $this->add($customSlug);
 
-        $maxVisits = $this->createInput(self::MAX_VISITS, false);
-        $maxVisits->getValidatorChain()->attach(new Validator\Digits())
-                                       ->attach(new Validator\GreaterThan(['min' => 1, 'inclusive' => true]));
-        $this->add($maxVisits);
+        $this->add($this->createPositiveNumberInput(self::MAX_VISITS));
+        $this->add($this->createPositiveNumberInput(self::SHORT_CODE_LENGTH));
 
         $this->add($this->createBooleanInput(self::FIND_IF_EXISTS, false));
 
@@ -51,4 +51,13 @@ class ShortUrlMetaInputFilter extends InputFilter
         $domain->getValidatorChain()->attach(new Validation\HostAndPortValidator());
         $this->add($domain);
     }
+
+    private function createPositiveNumberInput(string $name): Input
+    {
+        $input = $this->createInput($name, false);
+        $input->getValidatorChain()->attach(new Validator\Digits())
+              ->attach(new Validator\GreaterThan(['min' => 1, 'inclusive' => true]));
+
+        return $input;
+    }
 }

module/Core/test/Entity/ShortUrlTest.php

@@ -8,6 +8,13 @@ use PHPUnit\Framework\TestCase;
 use Shlinkio\Shlink\Core\Entity\ShortUrl;
 use Shlinkio\Shlink\Core\Exception\ShortCodeCannotBeRegeneratedException;
 use Shlinkio\Shlink\Core\Model\ShortUrlMeta;
+use Shlinkio\Shlink\Core\Validation\ShortUrlMetaInputFilter;
+
+use function Functional\map;
+use function range;
+use function strlen;
+
+use const Shlinkio\Shlink\Core\DEFAULT_SHORT_CODES_LENGTH;
 
 class ShortUrlTest extends TestCase
 {
@@ -48,4 +55,23 @@ class ShortUrlTest extends TestCase
 
         $this->assertNotEquals($firstShortCode, $secondShortCode);
     }
+
+    /**
+     * @test
+     * @dataProvider provideLengths
+     */
+    public function shortCodesHaveExpectedLength(?int $length, int $expectedLength): void
+    {
+        $shortUrl = new ShortUrl('', ShortUrlMeta::fromRawData(
+            [ShortUrlMetaInputFilter::SHORT_CODE_LENGTH => $length],
+        ));
+
+        $this->assertEquals($expectedLength, strlen($shortUrl->getShortCode()));
+    }
+
+    public function provideLengths(): iterable
+    {
+        yield [null, DEFAULT_SHORT_CODES_LENGTH];
+        yield from map(range(1, 10), fn (int $value) => [$value, $value]);
+    }
 }