Add support for relationships in CaseSort

src/Sorts/CaseSort.php

@@ -5,6 +5,9 @@
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Query\Expression;
 use Spatie\QueryBuilder\Sorts\Sort;
+use TeamQ\QueryBuilder\Concerns\HasPropertyRelationship;
+use TeamQ\QueryBuilder\Enums\AggregationType;
+use TeamQ\QueryBuilder\Enums\JoinType;
 
 /**
  * Add support for sorting using select case, for cases such as Enums, States, Constants,
@@ -16,26 +19,58 @@
  */
 class CaseSort implements Sort
 {
-    /**
-     * @param  array<string|int, string|int>  $cases
-     */
-    public function __construct(protected array $cases)
-    {
+    use HasPropertyRelationship;
+
+    public function __construct(
+        protected array $cases,
+        private readonly JoinType $joinType = JoinType::Inner,
+        private readonly ?AggregationType $aggregationType = null,
+    ) {
     }
 
     /**
      * {@inheritDoc}
      */
     public function __invoke(Builder $query, bool $descending, string $property): void
     {
-        $column = $query->qualifyColumn($property);
+        if ($this->isRelationProperty($query, $property)) {
+            [$relationName, $column] = $this->getConstraintParts($property);
+
+            $relation = $query;
+
+            foreach (explode('.', $relationName) as $partial) {
+                $relation = $relation->getRelation($partial);
+            }
+
+            $expression = $this->getQueryExpression($relation->qualifyColumn($column));
+
+            $query
+                ->orderByPowerJoins(
+                    [$relationName, new Expression($expression)],
+                    $descending ? 'desc' : 'asc',
+                    $this->aggregationType?->value,
+                    $this->joinType->value
+                );
 
+            return;
+        }
+
+        $expression = $this->getQueryExpression($query->qualifyColumn($property));
+
+        $query->orderBy(new Expression($expression), $descending ? 'desc' : 'asc');
+    }
+
+    /**
+     * Generates the SQL expression that will be used to sort.
+     */
+    protected function getQueryExpression(string $column): string
+    {
         $sql = 'case ';
         foreach ($this->cases as $key => $value) {
             $sql .= "when {$column} = {$key} then '{$value}' ";
         }
         $sql .= 'end ';
 
-        $query->orderBy(new Expression($sql), $descending ? 'desc' : 'asc');
+        return $sql;
     }
 }

tests/Sorts/CaseSortTest.php

@@ -4,14 +4,24 @@
 use Spatie\QueryBuilder\QueryBuilder;
 use Symfony\Component\HttpFoundation\Request;
 use TeamQ\QueryBuilder\Sorts\CaseSort;
+use Tests\Mocks\Enums\AuthorTypeEnum;
 use Tests\Mocks\Enums\BookClassificationEnum;
+use Tests\Mocks\Models\Author;
 use Tests\Mocks\Models\Book;
 
 beforeEach(function () {
     $this->request = new Illuminate\Http\Request();
     $this->request->setMethod(Request::METHOD_GET);
 
     $this->firstBook = Book::factory()
+        ->for(
+            Author::factory()
+                ->create([
+                    'name' => 'Spatie',
+                    'email' => '[email protected]',
+                    'type' => AuthorTypeEnum::VIP,
+                ])
+        )
         ->create([
             'title' => 'Laravel Beyond Crud',
             'isbn' => '758952123',
@@ -20,6 +30,14 @@
         ]);
 
     $this->secondBook = Book::factory()
+        ->for(
+            Author::factory()
+                ->create([
+                    'name' => 'Spatie',
+                    'email' => '[email protected]',
+                    'type' => AuthorTypeEnum::Public,
+                ])
+        )
         ->create([
             'title' => 'Domain Driven Design for Laravel',
             'isbn' => '5895421369',
@@ -79,5 +97,26 @@
 });
 
 it('sort records by relationship fields', function () {
+    $this->request->query->add([
+        'sort' => 'author.type',
+    ]);
+
+    $cases = collect(AuthorTypeEnum::cases())
+        ->pluck('name', 'value')
+        ->toArray();
+
+    $queryBuilder = QueryBuilder::for(Book::class, $this->request)
+        ->allowedSorts([
+            AllowedSort::custom('author.type', new CaseSort($cases)),
+        ]);
 
-})->skip('WIP');
+    expect($queryBuilder->toSql())
+        ->toBe(
+            "select `books`.* from `books` inner join `authors` on `books`.`author_id` = `authors`.`id` order by case when authors.type = 1 then 'VIP' when authors.type = 2 then 'Public' when authors.type = 3 then 'Private' end  asc"
+        )
+        ->and($queryBuilder->get())
+        ->sequence(
+            fn ($book) => $book->author->type->toBe(AuthorTypeEnum::Public),
+            fn ($book) => $book->author->type->toBe(AuthorTypeEnum::VIP),
+        );
+});