[5.x] filter modifier (#10962)

Co-authored-by: Jason Varga <[email protected]>

src/Modifiers/CoreModifiers.php

@@ -710,6 +710,19 @@ public function favicon($value)
         return Html::favicon($value);
     }
 
+    /**
+     * Filters out empty values from an array or collection.
+     *
+     * @param  array  $value
+     * @return array
+     */
+    public function filterEmpty($value)
+    {
+        return collect($value)
+            ->filter()
+            ->when(is_array($value), fn ($collection) => $collection->all());
+    }
+
     /**
      * Returns the first $params[0] characters of a string, or the first element of an array.
      *

tests/Modifiers/FilterEmptyTest.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Tests\Modifiers;
+
+use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\Test;
+use Statamic\Modifiers\Modify;
+use Tests\TestCase;
+
+#[Group('array')]
+class FilterEmptyTest extends TestCase
+{
+    #[Test]
+    public function it_removes_null_values_from_an_array(): void
+    {
+        $modified = $this->modify(['one' => 'one', null, 'two' => 'two', 'three' => null, 'four' => 'four']);
+        $this->assertEquals(['one' => 'one', 'two' => 'two', 'four' => 'four'], $modified);
+    }
+
+    #[Test]
+    public function it_removes_null_values_from_a_collection(): void
+    {
+        $modified = $this->modify(collect(['one' => 'one', null, 'two' => 'two', 'three' => null, 'four' => 'four']));
+        $this->assertEquals(['one' => 'one', 'two' => 'two', 'four' => 'four'], $modified->all());
+    }
+
+    private function modify($value, $params = [])
+    {
+        return Modify::value($value)->filterEmpty($params)->fetch();
+    }
+}