Add support for starts_with operator

The `starts_with` operator allows to search for string fields that start with a given substring

src/Filterable.php

@@ -72,6 +72,7 @@ protected function allowedOperators(): string
             'between',
             'not_between',
             'contains',
+            'starts_with',
             'between_date',
             'in',
         ]);

src/FiltersBuilder.php

@@ -82,6 +82,11 @@ protected function contains(array $filter, Builder $query): Builder
         return $query->where($filter['column'], 'like', '%'.$filter['query_1'].'%', $filter['match']);
     }
 
+    protected function startsWith(array $filter, Builder $query): Builder
+    {
+        return $query->where($filter['column'], 'like', $filter['query_1'].'%', $filter['match']);
+    }
+
     protected function betweenDate(array $filter, Builder $query): Builder
     {
         return $query->whereBetween($filter['column'], [

tests/FiltersBuilderTest.php

@@ -233,6 +233,26 @@ public function it_filters_by_string_field_contains_value(): void
         self::assertNotTrue($results->contains($this->client3));
     }
 
+    /** @test */
+    public function it_filters_by_string_field_starts_with_value(): void
+    {
+        $results = Client::filter([
+            'filters' => [
+                [
+                    'column' => 'name',
+                    'operator' => 'starts_with',
+                    'query_1' => 'j',
+                    'query_2' => null,
+                ],
+            ],
+        ])->get();
+
+        self::assertCount(2, $results);
+        self::assertTrue($results->contains($this->client1));
+        self::assertTrue($results->contains($this->client2));
+        self::assertNotTrue($results->contains($this->client3));
+    }
+
     /*
     |--------------------------------------------------------------------------
     | Filtering date/datetime fields on model