Fix empty array check

src/Parameters.php

@@ -27,10 +27,25 @@ class Parameters
      */
     public static function json(string $name, object|array $document): array
     {
-        return [$name => match (is_object($document) && method_exists($document, 'toJson')) {
+        $flags = JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES;
-            true  => $document->toJson(),
+
-            false => json_encode($document, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES)
+        if (is_object($document)) {
-        }];
+            return [
+                $name => method_exists($document, 'toJson') ? $document->toJson($flags) : json_encode($document, $flags)
+            ];
+        }
+
+        $key = array_key_first($document);
+        if (is_array($document[$key])) {
+            if (empty($document[$key])) return [$name => json_encode($document, $flags)];
+            if (method_exists($document[$key][array_key_first($document[$key])], 'toJson')) {
+                return [
+                    $name => sprintf('{%s:[%s]}', json_encode($key, $flags),
+                        implode(',', array_map(fn($it) => $it->toJson($flags), $document[$key])))
+                ];
+            }
+        }
+        return [$name => json_encode($document, $flags)];
     }
 
     /**

tests/unit/ParametersTest.php

@@ -33,6 +33,19 @@ class ParametersTest extends TestCase
             'JSON parameter not constructed correctly');
     }
 
+    public function testJsonSucceedsForArrayWithEmptyArrayParameter(): void
+    {
+        $this->assertEquals([':it' => '{"id":18,"urls":[]}'], Parameters::json(':it', ['id' => 18, 'urls' => []]),
+            'JSON parameter not constructed correctly');
+    }
+
+    #[TestDox('json succeeds for 1D array with empty array parameter')]
+    public function testJsonSucceedsFor1DArrayWithEmptyArrayParameter(): void
+    {
+        $this->assertEquals([':it' => '{"urls":[]}'], Parameters::json(':it', ['urls' => []]),
+            'JSON parameter not constructed correctly');
+    }
+
     #[TestDox('json succeeds for stdClass')]
     public function testJsonSucceedsForStdClass(): void
     {
@@ -50,6 +63,13 @@ class ParametersTest extends TestCase
             'JSON parameter not constructed correctly');
     }
 
+    public function testJsonSucceedsForArrayOfPjsonClass(): void
+    {
+        $this->assertEquals([':it' => '{"pjson":[{"id":"997","name":"another test","num_value":94}]}'],
+            Parameters::json(':it',
+                ['pjson' => [new PjsonDocument(new PjsonId('997'), 'another test', 94, 'nothing')]]),
+            'JSON parameter not constructed correctly');
+    }
 
     public function testNameFieldsSucceeds(): void
     {