Allow inserting pipes using a class name as matcher

src/Generator.php

@@ -354,16 +354,7 @@ public function addProcessor($processor, ?string $before = null): Generator
         if (!$before) {
             $processors->add($processor);
         } else {
-            $matcher = function (array $pipes) use ($before) {
-                foreach ($pipes as $ii => $current) {
-                    if ($current instanceof $before) {
-                        return $ii;
-                    }
-                }
-
-                return null;
-            };
-            $processors->insert($processor, $matcher);
+            $processors->insert($processor, $before);
         }
 
         $this->processorPipeline = $processors;

src/Pipeline.php

@@ -73,10 +73,25 @@ public function remove($pipe = null, ?callable $matcher = null): Pipeline
     }
 
     /**
-     * @param callable $matcher Callable to determine the position to insert (returned as `int`)
+     * @param callable|class-string $matcher used to determine the position to insert
+     *                                       either an `int` from a callable or, in the case of `$matcher` being
+     *                                       a `class-string`, the position before the first pipe of that class
      */
-    public function insert(callable $pipe, callable $matcher): Pipeline
+    public function insert(callable $pipe, $matcher): Pipeline
     {
+        if (is_string($matcher)) {
+            $before = $matcher;
+            $matcher = function (array $pipes) use ($before) {
+                foreach ($pipes as $ii => $current) {
+                    if ($current instanceof $before) {
+                        return $ii;
+                    }
+                }
+
+                return null;
+            };
+        }
+
         $index = $matcher($this->pipes);
         if (null === $index || $index < 0 || $index > count($this->pipes)) {
             throw new OpenApiException('Matcher result out of range');

tests/PipelineTest.php

@@ -89,7 +89,7 @@ public function testRemoveClassString()
         $this->assertEquals('c', $pipeline->process(''));
     }
 
-    public function testInsert()
+    public function testInsertMatcher()
     {
         $pipeline = new Pipeline();
 
@@ -100,4 +100,16 @@ public function testInsert()
         $pipeline->insert($this->pipe('y'), function ($pipes) { return 1; });
         $this->assertEquals('xyz', $pipeline->process(''));
     }
+
+    public function testInsertClassString()
+    {
+        $pipeline = new Pipeline();
+
+        $pipeline->add($this);
+        $pipeline->add($this->pipe('y'));
+        $this->assertEquals('xy', $pipeline->process(''));
+
+        $pipeline->insert($this->pipe('a'), __CLASS__);
+        $this->assertEquals('axy', $pipeline->process(''));
+    }
 }