Add slugify Method to Str Class and toBeSlug Assertion to Expectation Class

src/Mixins/Expectation.php

@@ -661,7 +661,7 @@ public function toHaveKeys(array $keys, string $message = ''): self
     {
         foreach ($keys as $k => $key) {
             if (is_array($key)) {
-                $this->toHaveKeys(array_keys(Arr::dot($key, $k.'.')), $message);
+                $this->toHaveKeys(array_keys(Arr::dot($key, $k . '.')), $message);
             } else {
                 $this->toHaveKey($key, message: $message);
             }
@@ -1159,4 +1159,21 @@ public function toBeUrl(string $message = ''): self
 
         return $this;
     }
+
+    /**
+     * Asserts that the value can be converted to a slug
+     *
+     * @return self<TValue>
+     */
+    public function toBeSlug(string $message = ''): self
+    {
+        if ($message === '') {
+            $message = "Failed asserting that {$this->value} can be converted to a slug.";
+        }
+
+        $slug = Str::slugify((string) $this->value);
+        Assert::assertNotEmpty($slug, $message);
+
+        return $this;
+    }
 }

src/Support/Str.php

@@ -61,7 +61,7 @@ public static function evaluable(string $code): string
     {
         $code = str_replace('_', '__', $code);
 
-        $code = self::PREFIX.str_replace(' ', '_', $code);
+        $code = self::PREFIX . str_replace(' ', '_', $code);
 
         // sticks to PHP8.2 function naming rules https://www.php.net/manual/en/functions.user-defined.php
         return (string) preg_replace('/[^a-zA-Z0-9_\x80-\xff]/', '_', $code);
@@ -116,4 +116,13 @@ public static function isUrl(string $value): bool
     {
         return (bool) filter_var($value, FILTER_VALIDATE_URL);
     }
+
+    /**
+     * Converts the given `$target` to a URL-friendly "slug".
+     */
+    public static function slugify(string $target): string
+    {
+        $target = preg_replace('/[^a-zA-Z0-9]+/', '-', $target);
+        return strtolower(trim($target, '-'));
+    }
 }

tests/Features/Expect/toBeSlug.php

@@ -0,0 +1,24 @@
+<?php
+
+use PHPUnit\Framework\ExpectationFailedException;
+
+test('pass', function () {
+    expect('This is a Test String!')->toBeSlug()
+        ->and('Another Test String')->toBeSlug();
+});
+
+test('failures', function () {
+    expect('')->toBeSlug();
+})->throws(ExpectationFailedException::class);
+
+test('failures with custom message', function () {
+    expect('')->toBeSlug('oh no!');
+})->throws(ExpectationFailedException::class, 'oh no!');
+
+test('failures with default message', function () {
+    expect('')->toBeSlug();
+})->throws(ExpectationFailedException::class, 'Failed asserting that  can be converted to a slug.');
+
+test('not failures', function () {
+    expect('This is a Test String!')->not->toBeSlug();
+})->throws(ExpectationFailedException::class);