Add support for Transformer instances

Author: AydinHassan

src/CodePatcher.php

@@ -11,6 +11,7 @@
 use PhpParser\PrettyPrinter\Standard;
 use PhpSchool\PhpWorkshop\Exercise\ExerciseInterface;
 use PhpSchool\PhpWorkshop\Exercise\SubmissionPatchable;
+use PhpSchool\PhpWorkshop\Patch\Transformer;
 
 /**
  * Service to apply patches to a student's solution. Accepts a default patch via the constructor.
@@ -102,10 +103,15 @@ private function applyPatch(Patch $patch, string $code): string
                 continue;
             }
 
-            if (is_callable($modifier)) {
+            if ($modifier instanceof \Closure) {
                 $statements = $modifier($statements);
                 continue;
             }
+
+            if ($modifier instanceof Transformer) {
+                $statements = $modifier->transform($statements);
+                continue;
+            }
         }
 
         if ($declare !== null && !$this->isFirstStatementStrictTypesDeclare($statements)) {

test/CodePatcherTest.php

@@ -95,7 +95,7 @@ public function codeProvider(): array
                 (new Patch())->withInsertion(new Insertion(Insertion::TYPE_BEFORE, '    <?php $before = "here";')),
                 "<?php\n\n\$before = \"here\";\n\$original = true;"
             ],
-            'transformer' => [
+            'transformer-closure' => [
                 '<?php $original = true;',
                 (new Patch())
                     ->withTransformer(function (array $statements) {
@@ -122,6 +122,22 @@ public function codeProvider(): array
                     }),
                 "<?php\n\ntry {\n    \$before = \"here\";\n    \$original = true;\n} catch (Exception \$e) {\n}"
             ],
+            'transformer-class' => [
+                '<?php $original = true;',
+                (new Patch())
+                    ->withTransformer(new class implements Patch\Transformer {
+                        public function transform(array $statements): array
+                        {
+                            return [
+                                new TryCatch(
+                                    $statements,
+                                    [new Catch_([new Name(\Exception::class)], new Variable('e'), [])]
+                                )
+                            ];
+                        }
+                    }),
+                "<?php\n\ntry {\n    \$original = true;\n} catch (Exception \$e) {\n}"
+            ],
         ];
     }