Abstract the key generator out to use an interface

config/short-url.php

@@ -197,4 +197,16 @@
     |
     */
     'user_agent_driver' => \AshAllenDesign\ShortURL\Classes\UserAgent\ParserPhpDriver::class,
+
+    /*
+    |--------------------------------------------------------------------------
+    | Short URL Key Generator Class
+    |--------------------------------------------------------------------------
+    |
+    | Define the class that should be used to handle the creation of a unique
+    | short URL key. This class must implement the following interface:
+    | AshAllenDesign\ShortURL\Interfaces\UrlKeyGenerator.
+    |
+    */
+    'url_key_generator' => \AshAllenDesign\ShortURL\Classes\KeyGenerator::class,
 ];

src/Classes/Builder.php

@@ -5,6 +5,7 @@
 use AshAllenDesign\ShortURL\Controllers\ShortURLController;
 use AshAllenDesign\ShortURL\Exceptions\ShortURLException;
 use AshAllenDesign\ShortURL\Exceptions\ValidationException;
+use AshAllenDesign\ShortURL\Interfaces\UrlKeyGenerator;
 use AshAllenDesign\ShortURL\Models\ShortURL;
 use Carbon\Carbon;
 use Closure;
@@ -19,10 +20,8 @@ class Builder
     /**
      * The class that is used for generating the
      * random URL keys.
-     *
-     * @var KeyGenerator
      */
-    private $keyGenerator;
+    private UrlKeyGenerator $keyGenerator;
 
     /**
      * The destination URL that the short URL will
@@ -177,19 +176,18 @@ class Builder
      * config variables are validated.
      *
      * @param  Validation|null  $validation
-     * @param  KeyGenerator|null  $keyGenerator
      *
      * @throws ValidationException
      */
-    public function __construct(Validation $validation = null, KeyGenerator $keyGenerator = null)
+    public function __construct(UrlKeyGenerator $urlKeyGenerator, Validation $validation = null)
     {
         if (! $validation) {
             $validation = new Validation();
         }
 
         $validation->validateConfig();
 
-        $this->keyGenerator = $keyGenerator ?? new KeyGenerator();
+        $this->keyGenerator = $urlKeyGenerator;
     }
 
     /**
@@ -422,11 +420,8 @@ public function urlKey(string $key): self
 
     /**
      * Explicitly set the key generator.
-     *
-     * @param  KeyGenerator  $keyGenerator
-     * @return $this
      */
-    public function keyGenerator(KeyGenerator $keyGenerator): self
+    public function keyGenerator(UrlKeyGenerator $keyGenerator): self
     {
         $this->keyGenerator = $keyGenerator;
 

src/Classes/KeyGenerator.php

@@ -2,10 +2,11 @@
 
 namespace AshAllenDesign\ShortURL\Classes;
 
+use AshAllenDesign\ShortURL\Interfaces\UrlKeyGenerator;
 use AshAllenDesign\ShortURL\Models\ShortURL;
 use Hashids\Hashids;
 
-class KeyGenerator
+class KeyGenerator implements UrlKeyGenerator
 {
     /**
      * The library class that is used for generating
@@ -18,21 +19,17 @@ class KeyGenerator
     /**
      * KeyGenerator constructor.
      */
-    public function __construct(Hashids $hashids = null)
+    public function __construct(Hashids $hashids)
     {
-        $this->hashids = $hashids ?: new Hashids(config('short-url.key_salt'), config('short-url.key_length'), config('short-url.alphabet'));
+        $this->hashids = $hashids;
     }
 
     /**
-     * Generate a unique and random URL key using the
-     * Hashids package. We start by predicting the
-     * unique ID that the ShortURL will have in
-     * the database. Then we can encode the ID
-     * to create a unique hash. On the very
-     * unlikely chance that a generated
-     * key collides with another key,
-     * we increment the ID and then
-     * attempt to create a new
+     * Generate a unique and random URL key using the Hashids package. We start by
+     * predicting the unique ID that the ShortURL will have in the database.
+     * Then we can encode the ID to create a unique hash. On the very
+     * unlikely chance that a generated key collides with another
+     * key, we increment the ID and then attempt to create a new
      * unique key again.
      *
      * @return string

src/Facades/ShortURL.php

@@ -3,8 +3,9 @@
 namespace AshAllenDesign\ShortURL\Facades;
 
 use AshAllenDesign\ShortURL\Classes\Builder;
-use AshAllenDesign\ShortURL\Classes\KeyGenerator;
+use AshAllenDesign\ShortURL\Interfaces\UrlKeyGenerator;
 use Carbon\Carbon;
+use Closure;
 use Illuminate\Support\Facades\Facade;
 use RuntimeException;
 
@@ -22,7 +23,7 @@
  * @method static self trackRefererURL(bool $track)
  * @method static self trackDeviceType(bool $track)
  * @method static self urlKey(string $key)
- * @method static self keyGenerator(KeyGenerator $keyGenerator)
+ * @method static self keyGenerator(UrlKeyGenerator $keyGenerator)
  * @method static self redirectStatusCode(int $statusCode)
  * @method static self resetOptions()
  * @method static self activateAt(Carbon $activationTime)

src/Interfaces/UrlKeyGenerator.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace AshAllenDesign\ShortURL\Interfaces;
+
+interface UrlKeyGenerator
+{
+    public function generateRandom(): string;
+
+    public function generateKeyUsing(int $seed = null): string;
+}

src/Models/Factories/ShortURLFactory.php

@@ -4,6 +4,7 @@
 
 use AshAllenDesign\ShortURL\Classes\KeyGenerator;
 use AshAllenDesign\ShortURL\Models\ShortURL;
+use Hashids\Hashids;
 use Illuminate\Database\Eloquent\Factories\Factory;
 
 /**
@@ -15,7 +16,7 @@ class ShortURLFactory extends Factory
 
     public function definition(): array
     {
-        $urlKey = (new KeyGenerator())->generateRandom();
+        $urlKey = (new KeyGenerator(new Hashids()))->generateRandom();
 
         return [
             'destination_url' => $this->faker->url(),

src/Providers/ShortURLProvider.php

@@ -3,9 +3,13 @@
 namespace AshAllenDesign\ShortURL\Providers;
 
 use AshAllenDesign\ShortURL\Classes\Builder;
+use AshAllenDesign\ShortURL\Classes\KeyGenerator;
 use AshAllenDesign\ShortURL\Classes\Validation;
 use AshAllenDesign\ShortURL\Exceptions\ValidationException;
+use AshAllenDesign\ShortURL\Interfaces\UrlKeyGenerator;
 use AshAllenDesign\ShortURL\Interfaces\UserAgentDriver;
+use Hashids\Hashids;
+use Illuminate\Foundation\Application;
 use Illuminate\Support\ServiceProvider;
 
 class ShortURLProvider extends ServiceProvider
@@ -19,9 +23,22 @@ public function register(): void
     {
         $this->mergeConfigFrom(__DIR__.'/../../config/short-url.php', 'short-url');
 
-        $this->app->bind('short-url.builder', function () {
-            return new Builder();
+        $this->app->bind(UserAgentDriver::class, config('short-url.user_agent_driver'));
+        $this->app->bind(UrlKeyGenerator::class, config('short-url.url_key_generator'));
+
+        $this->app->bind('short-url.builder', function (Application $app): Builder {
+            return new Builder(
+                urlKeyGenerator: $app->make(UrlKeyGenerator::class),
+            );
         });
+
+        $this->app->when(KeyGenerator::class)
+            ->needs(Hashids::class)
+            ->give(fn (): Hashids => new Hashids(
+                salt: config('short-url.key_salt'),
+                minHashLength: (int) config('short-url.key_length'),
+                alphabet: config('short-url.alphabet')
+            ));
     }
 
     /**
@@ -49,7 +66,5 @@ public function boot(): void
         if (config('short-url') && config('short-url.validate_config')) {
             (new Validation())->validateConfig();
         }
-
-        $this->app->bind(UserAgentDriver::class, config('short-url.user_agent_driver'));
     }
 }