Added option to provide custom slug when creating a short url

composer.json

@@ -14,6 +14,7 @@
     "require": {
         "php": "^7.0",
         "acelaya/ze-content-based-error-handler": "^2.0",
+        "cocur/slugify": "^3.0",
         "doctrine/annotations": "^1.4 <1.5",
         "doctrine/cache": "^1.6 <1.7",
         "doctrine/collections": "^1.4 <1.5",

module/Core/src/Exception/NonUniqueSlugException.php

@@ -0,0 +1,14 @@
+<?php
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Core\Exception;
+
+use Shlinkio\Shlink\Common\Exception\InvalidArgumentException;
+
+class NonUniqueSlugException extends InvalidArgumentException
+{
+    public static function fromSlug(string $slug): self
+    {
+        return new self(sprintf('Provided slug "%s" is not unique.', $slug));
+    }
+}

module/Core/src/Service/UrlShortener.php

@@ -3,6 +3,8 @@ declare(strict_types=1);
 
 namespace Shlinkio\Shlink\Core\Service;
 
+use Cocur\Slugify\Slugify;
+use Cocur\Slugify\SlugifyInterface;
 use Doctrine\Common\Cache\Cache;
 use Doctrine\ORM\EntityManagerInterface;
 use Doctrine\ORM\ORMException;
@@ -14,6 +16,7 @@ use Shlinkio\Shlink\Core\Entity\ShortUrl;
 use Shlinkio\Shlink\Core\Exception\EntityDoesNotExistException;
 use Shlinkio\Shlink\Core\Exception\InvalidShortCodeException;
 use Shlinkio\Shlink\Core\Exception\InvalidUrlException;
+use Shlinkio\Shlink\Core\Exception\NonUniqueSlugException;
 use Shlinkio\Shlink\Core\Repository\ShortUrlRepository;
 use Shlinkio\Shlink\Core\Util\TagManagerTrait;
 
@@ -39,17 +42,23 @@ class UrlShortener implements UrlShortenerInterface
      * @var Cache
      */
     private $cache;
+    /**
+     * @var SlugifyInterface
+     */
+    private $slugger;
 
     public function __construct(
         ClientInterface $httpClient,
         EntityManagerInterface $em,
         Cache $cache,
-        $chars = self::DEFAULT_CHARS
+        $chars = self::DEFAULT_CHARS,
+        SlugifyInterface $slugger = null
     ) {
         $this->httpClient = $httpClient;
         $this->em = $em;
         $this->chars = empty($chars) ? self::DEFAULT_CHARS : $chars;
         $this->cache = $cache;
+        $this->slugger = $slugger ?: new Slugify();
     }
 
     /**
@@ -59,7 +68,9 @@ class UrlShortener implements UrlShortenerInterface
      * @param string[] $tags
      * @param \DateTime|null $validSince
      * @param \DateTime|null $validUntil
+     * @param string|null $customSlug
      * @return string
+     * @throws NonUniqueSlugException
      * @throws InvalidUrlException
      * @throws RuntimeException
      */
@@ -67,7 +78,8 @@ class UrlShortener implements UrlShortenerInterface
         UriInterface $url,
         array $tags = [],
         \DateTime $validSince = null,
-        \DateTime $validUntil = null
+        \DateTime $validUntil = null,
+        string $customSlug = null
     ): string {
         // If the url already exists in the database, just return its short code
         $shortUrl = $this->em->getRepository(ShortUrl::class)->findOneBy([
@@ -79,6 +91,8 @@ class UrlShortener implements UrlShortenerInterface
 
         // Check that the URL exists
         $this->checkUrlExists($url);
+        $customSlug = $this->processCustomSlug($customSlug);
+
 
         // Transactionally insert the short url, then generate the short code and finally update the short code
         try {
@@ -93,7 +107,7 @@ class UrlShortener implements UrlShortenerInterface
             $this->em->flush();
 
             // Generate the short code and persist it
-            $shortCode = $this->convertAutoincrementIdToShortCode($shortUrl->getId());
+            $shortCode = $customSlug ?? $this->convertAutoincrementIdToShortCode($shortUrl->getId());
             $shortUrl->setShortCode($shortCode)
                      ->setTags($this->tagNamesToEntities($this->em, $tags));
             $this->em->flush();
@@ -116,7 +130,7 @@ class UrlShortener implements UrlShortenerInterface
      * @param UriInterface $url
      * @return void
      */
-    protected function checkUrlExists(UriInterface $url)
+    private function checkUrlExists(UriInterface $url)
     {
         try {
             $this->httpClient->request('GET', $url, ['allow_redirects' => [
@@ -133,7 +147,7 @@ class UrlShortener implements UrlShortenerInterface
      * @param int $id
      * @return string
      */
-    protected function convertAutoincrementIdToShortCode($id)
+    private function convertAutoincrementIdToShortCode($id)
     {
         $id = ((int) $id) + 200000; // Increment the Id so that the generated shortcode is not too short
         $length = strlen($this->chars);
@@ -148,6 +162,22 @@ class UrlShortener implements UrlShortenerInterface
         return $this->chars[(int) $id] . $code;
     }
 
+    private function processCustomSlug($customSlug)
+    {
+        if ($customSlug === null) {
+            return null;
+        }
+
+        // If a custom slug was provided, check it is unique
+        $customSlug = $this->slugger->slugify($customSlug);
+        $shortUrl = $this->em->getRepository(ShortUrl::class)->findOneBy(['shortCode' => $customSlug]);
+        if ($shortUrl !== null) {
+            throw NonUniqueSlugException::fromSlug($customSlug);
+        }
+
+        return $customSlug;
+    }
+
     /**
      * Tries to find the mapped URL for provided short code. Returns null if not found
      *

module/Core/src/Service/UrlShortenerInterface.php

@@ -8,6 +8,7 @@ use Shlinkio\Shlink\Common\Exception\RuntimeException;
 use Shlinkio\Shlink\Core\Exception\EntityDoesNotExistException;
 use Shlinkio\Shlink\Core\Exception\InvalidShortCodeException;
 use Shlinkio\Shlink\Core\Exception\InvalidUrlException;
+use Shlinkio\Shlink\Core\Exception\NonUniqueSlugException;
 
 interface UrlShortenerInterface
 {
@@ -18,7 +19,9 @@ interface UrlShortenerInterface
      * @param string[] $tags
      * @param \DateTime|null $validSince
      * @param \DateTime|null $validUntil
+     * @param string|null $customSlug
      * @return string
+     * @throws NonUniqueSlugException
      * @throws InvalidUrlException
      * @throws RuntimeException
      */
@@ -26,7 +29,8 @@ interface UrlShortenerInterface
         UriInterface $url,
         array $tags = [],
         \DateTime $validSince = null,
-        \DateTime $validUntil = null
+        \DateTime $validUntil = null,
+        string $customSlug = null
     ): string;
 
     /**

module/Core/test/Service/UrlShortenerTest.php

@@ -3,6 +3,7 @@ declare(strict_types=1);
 
 namespace ShlinkioTest\Shlink\Core\Service;
 
+use Cocur\Slugify\SlugifyInterface;
 use Doctrine\Common\Cache\ArrayCache;
 use Doctrine\Common\Cache\Cache;
 use Doctrine\Common\Persistence\ObjectRepository;
@@ -14,8 +15,10 @@ use GuzzleHttp\Exception\ClientException;
 use GuzzleHttp\Psr7\Request;
 use PHPUnit\Framework\TestCase;
 use Prophecy\Argument;
+use Prophecy\Prophecy\MethodProphecy;
 use Prophecy\Prophecy\ObjectProphecy;
 use Shlinkio\Shlink\Core\Entity\ShortUrl;
+use Shlinkio\Shlink\Core\Exception\NonUniqueSlugException;
 use Shlinkio\Shlink\Core\Repository\ShortUrlRepositoryInterface;
 use Shlinkio\Shlink\Core\Service\UrlShortener;
 use Zend\Diactoros\Uri;
@@ -38,6 +41,10 @@ class UrlShortenerTest extends TestCase
      * @var Cache
      */
     protected $cache;
+    /**
+     * @var ObjectProphecy
+     */
+    protected $slugger;
 
     public function setUp()
     {
@@ -60,8 +67,15 @@ class UrlShortenerTest extends TestCase
         $this->em->getRepository(ShortUrl::class)->willReturn($repo->reveal());
 
         $this->cache = new ArrayCache();
+        $this->slugger = $this->prophesize(SlugifyInterface::class);
 
-        $this->urlShortener = new UrlShortener($this->httpClient->reveal(), $this->em->reveal(), $this->cache);
+        $this->urlShortener = new UrlShortener(
+            $this->httpClient->reveal(),
+            $this->em->reveal(),
+            $this->cache,
+            UrlShortener::DEFAULT_CHARS,
+            $this->slugger->reveal()
+        );
     }
 
     /**
@@ -117,6 +131,54 @@ class UrlShortenerTest extends TestCase
         $this->assertEquals($shortUrl->getShortCode(), $shortCode);
     }
 
+    /**
+     * @test
+     */
+    public function whenCustomSlugIsProvidedItIsUsed()
+    {
+        /** @var MethodProphecy $slugify */
+        $slugify = $this->slugger->slugify('custom-slug')->willReturnArgument();
+
+        $this->urlShortener->urlToShortCode(
+            new Uri('http://foobar.com/12345/hello?foo=bar'),
+            [],
+            null,
+            null,
+            'custom-slug'
+        );
+
+        $slugify->shouldHaveBeenCalledTimes(1);
+    }
+
+    /**
+     * @test
+     */
+    public function exceptionIsThrownWhenNonUniqueSlugIsProvided()
+    {
+        /** @var MethodProphecy $slugify */
+        $slugify = $this->slugger->slugify('custom-slug')->willReturnArgument();
+
+        $repo = $this->prophesize(ShortUrlRepositoryInterface::class);
+        /** @var MethodProphecy $findBySlug */
+        $findBySlug = $repo->findOneBy(['shortCode' => 'custom-slug'])->willReturn(new ShortUrl());
+        $repo->findOneBy(Argument::cetera())->willReturn(null);
+        /** @var MethodProphecy $getRepo */
+        $getRepo = $this->em->getRepository(ShortUrl::class)->willReturn($repo->reveal());
+
+        $slugify->shouldBeCalledTimes(1);
+        $findBySlug->shouldBeCalledTimes(1);
+        $getRepo->shouldBeCalled();
+        $this->expectException(NonUniqueSlugException::class);
+
+        $this->urlShortener->urlToShortCode(
+            new Uri('http://foobar.com/12345/hello?foo=bar'),
+            [],
+            null,
+            null,
+            'custom-slug'
+        );
+    }
+
     /**
      * @test
      */