Fix MethodGenerator parameter sorting, when an explicit sorting is provided

psalm-baseline.xml

@@ -1593,7 +1593,7 @@
     <InvalidArgument occurrences="1">
       <code>new stdClass()</code>
     </InvalidArgument>
-    <MissingReturnType occurrences="20">
+    <MissingReturnType occurrences="22">
       <code>testByRefReturnType</code>
       <code>testCopyMethodSignature</code>
       <code>testCreateFromArray</code>
@@ -1609,6 +1609,8 @@
       <code>testMethodFromReflectionMultiLinesIndention</code>
       <code>testMethodParameterAccessors</code>
       <code>testMethodParameterMutator</code>
+      <code>testSetMethodParameter</code>
+      <code>testSetMethodParameters</code>
       <code>testMethodWithFinalModifierIsEmitted</code>
       <code>testMethodWithFinalModifierIsNotEmittedWhenMethodIsAbstract</code>
       <code>testMethodWithStaticModifierIsEmitted</code>

src/Generator/MethodGenerator.php

@@ -15,6 +15,7 @@
 use function strtolower;
 use function substr;
 use function trim;
+use function usort;
 
 class MethodGenerator extends AbstractMemberGenerator
 {
@@ -216,6 +217,8 @@ public function setParameters(array $parameters)
             $this->setParameter($parameter);
         }
 
+        $this->sortParameters();
+
         return $this;
     }
 
@@ -244,6 +247,8 @@ public function setParameter($parameter)
 
         $this->parameters[$parameter->getName()] = $parameter;
 
+        $this->sortParameters();
+
         return $this;
     }
 
@@ -305,6 +310,16 @@ public function setReturnsReference($returnsReference)
         return $this;
     }
 
+    /**
+     * Sort parameters by their position
+     */
+    private function sortParameters(): void
+    {
+        usort($this->parameters, static function (ParameterGenerator $item1, ParameterGenerator $item2) {
+            return $item1->getPosition() <=> $item2->getPosition();
+        });
+    }
+
     /**
      * @return string
      */

test/Generator/MethodGeneratorTest.php

@@ -21,6 +21,7 @@
 use stdClass;
 
 use function array_filter;
+use function array_map;
 use function array_shift;
 use function array_values;
 
@@ -74,6 +75,40 @@ public function testMethodParameterMutator()
         $methodGenerator->setParameter(new stdClass());
     }
 
+    public function testSetMethodParameter()
+    {
+        $methodGenerator = new MethodGenerator();
+
+        $methodGenerator->setParameter('foo');
+
+        $params = $methodGenerator->getParameters();
+        self::assertCount(1, $params);
+
+        /** @var ParameterGenerator $foo */
+        $foo = array_shift($params);
+        self::assertInstanceOf(ParameterGenerator::class, $foo);
+        self::assertSame('foo', $foo->getName());
+    }
+
+    public function testSetMethodParameters()
+    {
+        $methodGenerator = new MethodGenerator();
+
+        $methodGenerator->setParameter('foo');
+        $methodGenerator->setParameter(['name' => 'bar', 'type' => 'array', 'position' => 2]);
+        $methodGenerator->setParameter(
+            ParameterGenerator::fromArray(['name' => 'baz', 'type' => stdClass::class, 'position' => 1])
+        );
+
+        $params = $methodGenerator->getParameters();
+
+        $sorting = array_map(static function (ParameterGenerator $parameter): string {
+            return $parameter->getName();
+        }, $params);
+
+        self::assertEquals(['foo', 'baz', 'bar'], $sorting);
+    }
+
     public function testMethodBodyGetterAndSetter()
     {
         $method = new MethodGenerator();