fix(transformer): fix property transformer with adder and remover methods

src/Transformer/PropertyTransformer/PropertyTransformer.php

@@ -4,6 +4,7 @@
 
 namespace AutoMapper\Transformer\PropertyTransformer;
 
+use AutoMapper\Extractor\WriteMutator;
 use AutoMapper\Generator\UniqueVariableScope;
 use AutoMapper\Metadata\PropertyMetadata;
 use AutoMapper\Transformer\AllowNullValueTransformerInterface;
@@ -48,12 +49,8 @@ public function transform(Expr $input, Expr $target, PropertyMetadata $propertyM
             }
         }
 
-        /*
-         * When using a custom transformer, we need to call the transform method of the custom transformer which has been injected into the mapper.
-         *
-         * $this->transformers['id']($input, $source, $context)
-         */
-        return [new Expr\MethodCall(
+        $statements = [];
+        $transformExpr = new Expr\MethodCall(
             new Expr\MethodCall(new Expr\PropertyFetch(new Expr\Variable('this'), 'transformerRegistry'), 'getPropertyTransformer', [
                 new Arg(new Scalar\String_($this->propertyTransformerId)),
             ]),
@@ -63,6 +60,40 @@ public function transform(Expr $input, Expr $target, PropertyMetadata $propertyM
                 new Arg($source),
                 new Arg($context),
             ]
-        ), []];
+        );
+
+        /*
+         * If mutator is type adder and remover, we need to loop over the transformed values and call the adder method for each value.
+         *
+         * $values = $this->transformers['id']($input, $source, $context);
+         * foreach ($values as $value) {
+         *     $target->add($value);
+         * }
+         */
+        if ($propertyMapping->target->writeMutator && $propertyMapping->target->writeMutator->type === WriteMutator::TYPE_ADDER_AND_REMOVER) {
+            $mappedValueVar = new Expr\Variable($uniqueVariableScope->getUniqueName('mappedValue'));
+
+            $statements[] = new Stmt\Expression(new Expr\Assign(
+                $mappedValueVar,
+                $transformExpr
+            ));
+
+            $loopValueVar = new Expr\Variable($uniqueVariableScope->getUniqueName('value'));
+
+            $statements[] = new Stmt\Foreach_($mappedValueVar, $loopValueVar, [
+                'stmts' => [
+                    new Stmt\Expression($propertyMapping->target->writeMutator->getExpression($target, $loopValueVar)),
+                ],
+            ]);
+
+            return [new Expr\Variable($uniqueVariableScope->getUniqueName('mappedValues')), $statements];
+        }
+
+        /*
+         * When using a custom transformer, we need to call the transform method of the custom transformer which has been injected into the mapper.
+         *
+         * $this->transformers['id']($input, $source, $context)
+         */
+        return [$transformExpr, []];
     }
 }

tests/AutoMapperTest.php

@@ -39,6 +39,9 @@
 use AutoMapper\Tests\Fixtures\HasDateTimeInterfaceWithMutableInstance;
 use AutoMapper\Tests\Fixtures\HasDateTimeInterfaceWithNullValue;
 use AutoMapper\Tests\Fixtures\HasDateTimeWithNullValue;
+use AutoMapper\Tests\Fixtures\Issue111\Colour;
+use AutoMapper\Tests\Fixtures\Issue111\ColourTransformer;
+use AutoMapper\Tests\Fixtures\Issue111\FooDto;
 use AutoMapper\Tests\Fixtures\ObjectsUnion\Bar;
 use AutoMapper\Tests\Fixtures\ObjectsUnion\Foo;
 use AutoMapper\Tests\Fixtures\ObjectsUnion\ObjectsUnionProperty;
@@ -1507,4 +1510,17 @@ public function testProviderEarlyReturn(): void
         self::assertSame('bar', $data->foo);
         self::assertSame('foo', $data->bar);
     }
+
+    public function testIssue111(): void
+    {
+        $fooDto = new FooDto();
+        $fooDto->colours = ['red', 'green', 'blue'];
+
+        $this->buildAutoMapper(propertyTransformers: [new ColourTransformer()]);
+
+        $foo = $this->autoMapper->map($fooDto, Fixtures\Issue111\Foo::class);
+
+        self::assertInstanceOf(Fixtures\Issue111\Foo::class, $foo);
+        self::assertEquals([new Colour('red'), new Colour('green'), new Colour('blue')], $foo->getColours());
+    }
 }

tests/Fixtures/Issue111/Colour.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace AutoMapper\Tests\Fixtures\Issue111;
+
+class Colour
+{
+    public function __construct(
+        public string $name
+    ) {
+    }
+}

tests/Fixtures/Issue111/ColourTransformer.php

@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace AutoMapper\Tests\Fixtures\Issue111;
+
+use AutoMapper\Transformer\PropertyTransformer\PropertyTransformerInterface;
+
+class ColourTransformer implements PropertyTransformerInterface
+{
+    public function transform(mixed $value, object|array $source, array $context): mixed
+    {
+        $colours = [];
+
+        foreach ($value as $colour) {
+            $colours[] = new Colour($colour);
+        }
+
+        return $colours;
+    }
+}

tests/Fixtures/Issue111/Foo.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace AutoMapper\Tests\Fixtures\Issue111;
+
+class Foo
+{
+    private array $colours = [];
+
+    public function getColours(): array
+    {
+        return $this->colours;
+    }
+
+    public function addColour(Colour $colour): void
+    {
+        $this->colours[] = $colour;
+    }
+
+    public function removeColour(Colour $colour): void
+    {
+        $key = array_search($colour, $this->colours, true);
+
+        if ($key !== false) {
+            unset($this->colours[$key]);
+        }
+    }
+}

tests/Fixtures/Issue111/FooDto.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace AutoMapper\Tests\Fixtures\Issue111;
+
+use AutoMapper\Attribute\MapTo;
+
+class FooDto
+{
+    #[MapTo(target: Foo::class, transformer: ColourTransformer::class)]
+    public array $colours = [];
+}