Count collections more efficiently in the length modifier (statamic#5802)

Author: jasonvarga

src/Modifiers/CoreModifiers.php

@@ -4,6 +4,7 @@
 
 use ArrayAccess;
 use Carbon\Carbon;
+use Countable;
 use Illuminate\Contracts\Support\Arrayable;
 use Illuminate\Support\Collection;
 use Statamic\Contracts\Assets\Asset as AssetContract;
@@ -1279,7 +1280,7 @@ public function lcfirst($value)
      */
     public function length($value)
     {
-        if (Compare::isQueryBuilder($value)) {
+        if (Compare::isQueryBuilder($value) || $value instanceof Countable) {
             return $value->count();
         }
 

tests/Modifiers/LengthTest.php

@@ -2,6 +2,9 @@
 
 namespace Tests\Modifiers;
 
+use Illuminate\Contracts\Support\Arrayable;
+use Mockery;
+use Statamic\Contracts\Query\Builder;
 use Statamic\Modifiers\Modify;
 use Tests\TestCase;
 
@@ -19,6 +22,36 @@ public function it_returns_the_numbers_of_items_in_array(): void
         $this->assertSame(3, $modified);
     }
 
+    /** @test */
+    public function it_returns_the_numbers_of_items_in_collection(): void
+    {
+        $arr = collect([
+            'Taylor Swift',
+            'Left Shark',
+            'Leroy Jenkins',
+        ]);
+        $modified = $this->modify($arr);
+        $this->assertSame(3, $modified);
+    }
+
+    /** @test */
+    public function it_returns_the_number_of_items_in_a_query()
+    {
+        $builder = Mockery::mock(Builder::class);
+        $builder->shouldReceive('count')->once()->andReturn(3);
+        $modified = $this->modify($builder);
+        $this->assertSame(3, $modified);
+    }
+
+    /** @test */
+    public function it_returns_the_number_of_items_in_an_arrayable()
+    {
+        $arrayable = Mockery::mock(Arrayable::class)->shouldReceive('toArray')->andReturn(['one', 'two'])->getMock();
+
+        $modified = $this->modify($arrayable);
+        $this->assertSame(2, $modified);
+    }
+
     /** @test */
     public function it_returns_the_numbers_of_chars_in_string(): void
     {
@@ -27,6 +60,17 @@ public function it_returns_the_numbers_of_chars_in_string(): void
         $this->assertSame(27, $modified);
     }
 
+    /** @test */
+    public function it_counts_a_collection_instead_of_toarraying_it(): void
+    {
+        $itemOne = Mockery::mock(Arrayable::class)->shouldNotReceive('toArray')->getMock();
+        $itemTwo = Mockery::mock(Arrayable::class)->shouldNotReceive('toArray')->getMock();
+
+        $arr = collect([$itemOne, $itemTwo]);
+        $modified = $this->modify($arr);
+        $this->assertSame(2, $modified);
+    }
+
     private function modify($value)
     {
         return Modify::value($value)->length()->fetch();