Counter parameter

Author: dantleech

lib/Extension/Core/CoreExtension.php

@@ -12,6 +12,7 @@
 use PhpBench\Pipeline\Extension\Core\Stage\Sampler\CurlSampler;
 use PhpBench\Pipeline\Extension\Core\Stage\Filter\KeysFilter;
 use PhpBench\Pipeline\Extension\Core\Stage\Aggregator\DescribeAggregator;
+use PhpBench\Pipeline\Extension\Core\Stage\Parameter\CounterParameter;
 
 class CoreExtension implements PipelineExtension
 {
@@ -28,6 +29,7 @@ public function __construct()
             'filter/keys' => new KeysFilter(),
             'output/stream' => new StreamOutput(),
             'parameter/serial' => new SerialParameter(),
+            'parameter/counter' => new CounterParameter(),
             'sampler/callable' => new CallableSampler(),
             'sampler/curl' => new CurlSampler(),
             'valve/take' => new TakeValve(),

tests/Unit/Extension/Core/Stage/Parameter/CounterParameterTest.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace PhpBench\Pipeline\Tests\Unit\Extension\Core\Stage\Parameter;
+
+use PhpBench\Pipeline\Tests\Unit\Extension\Core\CoreTestCase;
+
+class CounterParameterTest extends CoreTestCase
+{
+    public function testYieldsAnIncrementingValue()
+    {
+        $generator = $this->pipeline()
+            ->stage('parameter/counter', [
+                'name' => 'inc',
+            ])
+            ->generator();
+
+        $generator->next();
+        $generator->next();
+        $generator->next();
+        $generator->next();
+        $generator->next();
+        $generator->next();
+
+        $result = $generator->current();
+
+        $this->assertEquals(['inc' => 7], $result);
+    }
+
+    public function testYieldsAnIncrementingValueWithStep2()
+    {
+        $generator = $this->pipeline()
+            ->stage('parameter/counter', [
+                'name' => 'inc',
+                'step' => 2,
+            ])
+            ->generator();
+
+        $generator->next();
+        $generator->next();
+        $generator->next();
+        $generator->next();
+        $generator->next();
+        $generator->next();
+
+        $result = $generator->current();
+
+        $this->assertEquals(['inc' => 14], $result);
+    }
+}