Merge pull request #31 from pitchart/feature/resource-termination

Feature/resource termination

src/Reducer/Termination/ToCsv.php

@@ -0,0 +1,69 @@
+<?php
+
+
+namespace Pitchart\Transformer\Reducer\Termination;
+
+
+use Pitchart\Transformer\Termination;
+use function Pitchart\Transformer\Transducer\to_array;
+use function Pitchart\Transformer\transform;
+
+class ToCsv implements Termination
+{
+    /**
+     * @var string
+     */
+    private $delimiter;
+
+    /**
+     * @var string
+     */
+    private $enclosure;
+
+    /**
+     * @var string
+     */
+    private $escapeChar;
+
+    /**
+     * ToCsv constructor.
+     *
+     * @param string $delimiter
+     * @param string $enclosure
+     * @param string $escapeChar
+     */
+    public function __construct(string $delimiter = ',', string $enclosure = '"', string $escapeChar = "\\")
+    {
+        $this->delimiter = $delimiter;
+        $this->enclosure = $enclosure;
+        $this->escapeChar = $escapeChar;
+    }
+
+    public function init()
+    {
+        return fopen('php://temp', 'w+');
+    }
+
+    /**
+     * @param resource $result
+     * @param mixed $current
+     */
+    public function step($result, $current)
+    {
+        if (!is_array($current)) {
+            if (is_iterable($current)) {
+                $current = transform($current)->toArray();
+            }
+            else {
+                $current = [(string) $current];
+            }
+        }
+        fputcsv($result, $current, $this->delimiter, $this->enclosure, $this->escapeChar);
+        return $result;
+    }
+
+    public function complete($result)
+    {
+        return $result;
+    }
+}

src/Reducer/Termination/ToResource.php

@@ -0,0 +1,49 @@
+<?php
+
+
+namespace Pitchart\Transformer\Reducer\Termination;
+
+
+use Pitchart\Transformer\Termination;
+
+class ToResource implements Termination
+{
+    /**
+     * @var callable
+     */
+    private $callback;
+
+    /**
+     * ToResource constructor.
+     *
+     * @param callable $callback
+     */
+    public function __construct(callable $callback = null)
+    {
+        if ($callback == null) {
+            $callback = 'Pitchart\Transformer\identity';
+        }
+        $this->callback = $callback;
+    }
+
+    public function init()
+    {
+        return fopen('php://temp', 'w+');
+    }
+
+    /**
+     * @param resource $result
+     * @param mixed $current
+     */
+    public function step($result, $current)
+    {
+        fwrite($result, (string) ($this->callback)($current));
+        return $result;
+    }
+
+    public function complete($result)
+    {
+        return $result;
+    }
+
+}

src/Transducer/transducers.php

@@ -620,6 +620,22 @@ function to_iterator()
     return new Reducer\Termination\ToIterator();
 }
 
+/**
+ * @return Reducer\Termination\ToResource
+ */
+function to_resource(?callable $callback = null)
+{
+    return new Reducer\Termination\ToResource($callback);
+}
+
+/**
+ * @return Reducer\Termination\ToCsv
+ */
+function to_csv(string $delimiter = ',', string $enclosure = '"', string $escapeChar = "\\")
+{
+    return new Reducer\Termination\ToCsv($delimiter, $enclosure, $escapeChar);
+}
+
 /**
  * @param string $operator
  *

src/Transformer.php

@@ -387,6 +387,26 @@ public function toIterator()
         return $this->terminate(t\to_iterator());
     }
 
+    /**
+     * @return resource
+     */
+    public function toResource(?callable $callback = null)
+    {
+        return $this->terminate(t\to_resource($callback));
+    }
+
+    /**
+     * @param string $delimiter
+     * @param string $enclosure
+     * @param string $escapeChar
+     *
+     * @return mixed
+     */
+    public function toCsv(string $delimiter = ',', string $enclosure = '"', string $escapeChar = "\\")
+    {
+        return $this->terminate(t\to_csv());
+    }
+
     /**
      * @return mixed
      */

tests/Reducer/Termination/ToCsvTest.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace Pitchart\Transformer\Tests\Reducer\Termination;
+
+use Pitchart\Transformer\Reducer;
+use Pitchart\Transformer\Reducer\Termination\ToCsv;
+use PHPUnit\Framework\TestCase;
+use Pitchart\Transformer\Termination;
+use function Pitchart\Transformer\transform;
+
+class ToCsvTest extends TestCase
+{
+    public function test_is_a_reducer()
+    {
+        $resource = new ToCsv();
+        self::assertInstanceOf(Reducer::class, $resource);
+    }
+
+    public function test_is_a_termination()
+    {
+        $resource = new ToCsv();
+        self::assertInstanceOf(Termination::class, $resource);
+    }
+
+    public function test_initializes_with_a_resource()
+    {
+        $resource = new ToCsv();
+        $init = $resource->init();
+
+        self::assertInternalType('resource', $init);
+    }
+
+    public function test_writes_array_content_on_resource()
+    {
+        $resource = transform([[1, 2, 3, 4]])->toCsv();
+        rewind($resource);
+
+        self::assertEquals("1,2,3,4\n", stream_get_contents($resource));
+    }
+
+    public function test_writes_iterable_content_on_resource()
+    {
+        $resource = transform([new \ArrayIterator([1, 2, 3, 4])])->toCsv();
+        rewind($resource);
+
+        self::assertEquals("1,2,3,4\n", stream_get_contents($resource));
+    }
+
+    public function test_writes_flat_content_on_resource()
+    {
+        $resource = transform([1, 2, 3, 4])->toCsv();
+        rewind($resource);
+
+        self::assertEquals("1\n2\n3\n4\n", stream_get_contents($resource));
+    }
+
+}

tests/Reducer/Termination/ToResourceTest.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Pitchart\Transformer\Tests\Reducer\Termination;
+
+use Pitchart\Transformer\Reducer;
+use Pitchart\Transformer\Reducer\Termination\ToResource;
+use PHPUnit\Framework\TestCase;
+use Pitchart\Transformer\Termination;
+use function Pitchart\Transformer\transform;
+
+class ToResourceTest extends TestCase
+{
+    public function test_is_a_reducer()
+    {
+        $resource = new ToResource(function ($item) { return (string) $item; });
+        self::assertInstanceOf(Reducer::class, $resource);
+    }
+
+    public function test_is_a_termination()
+    {
+        $resource = new ToResource(function ($item) { return (string) $item; });
+        self::assertInstanceOf(Termination::class, $resource);
+    }
+
+    public function test_initializes_with_a_resource()
+    {
+        $resource = new ToResource(function ($item) { return (string) $item; });
+        $init = $resource->init();
+
+        self::assertInternalType('resource', $init);
+    }
+
+    public function test_writes_content_on_resource()
+    {
+        $resource = transform([1, 2, 3, 4])->toResource();
+        rewind($resource);
+
+        self::assertEquals('1234', stream_get_contents($resource));
+    }
+
+    public function test_writes_content_on_resource_with_callback()
+    {
+        $resource = transform([1, 2, 3, 4])->toResource(function ($item) {
+            return sprintf("%s\n", $item);
+        });
+        rewind($resource);
+
+        self::assertEquals("1\n2\n3\n4\n", stream_get_contents($resource));
+    }
+}