Workover of pricecalculator class and test

* add scale to the other price calculator methods
* add unit converter facade

src/Facade/UnitConverter.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace MarcelStrahl\PriceCalculator\Facade;
+
+use MarcelStrahl\PriceCalculator\UnitConverter as UnitConverterService;
+use MarcelStrahl\PriceCalculator\Factory\Converter as ConverterFactory;
+
+/**
+ * Class UnitConverter
+ * @author Marcel Strahl <[email protected]>
+ * @package MarcelStrahl\PriceCalculator\Facade
+ */
+class UnitConverter
+{
+    /**
+     * @return UnitConverterService
+     */
+    public static function getConverter(): UnitConverterService
+    {
+        return (new self)->createUnitConverter();
+    }
+
+    /**
+     * @return UnitConverterService
+     */
+    private function createUnitConverter(): UnitConverterService
+    {
+        return new UnitConverterService($this->createFactory());
+    }
+
+    /**
+     * @return ConverterFactory
+     */
+    private function createFactory(): ConverterFactory
+    {
+        return new ConverterFactory();
+    }
+}

src/PriceCalculator.php

@@ -34,7 +34,7 @@ public function __construct(VatInterface $vat)
      */
     public function addPrice(float $total, float $price): float
     {
-        return (float)bcadd($total, $price);
+        return (float)bcadd($total, $price,2);
     }
 
     /**
@@ -59,7 +59,7 @@ public function subPrice(float $total, float $price): float
      */
     public function mulPrice(float $amount, float $price): float
     {
-        return (float)bcmul($price, $amount);
+        return (float)bcmul($price, $amount, 2);
     }
 
     /**

tests/Facade/UnitConverterTest.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace MarcelStrahl\PriceCalculator\Tests\Facade;
+
+use MarcelStrahl\PriceCalculator\UnitConverterInterface;
+use PHPUnit\Framework\TestCase;
+use MarcelStrahl\PriceCalculator\Facade\UnitConverter as UnitConverterFacade;
+
+/**
+ * Class UnitConverterTest
+ * @author Marcel Strahl <[email protected]>
+ * @package MarcelStrahl\PriceCalculator\Tests\Facade
+ */
+class UnitConverterTest extends TestCase
+{
+    /**
+     * @return void
+     */
+    public function testCanInitPriceCalculatorFacade(): void
+    {
+        $facade = new UnitConverterFacade();
+        $this->assertInstanceOf(UnitConverterFacade::class, $facade);
+    }
+
+    /**
+     * @return void
+     */
+    public function testCanGetUnitConverter(): void
+    {
+        $facade = new UnitConverterFacade();
+        $unitConverter = $facade::getConverter();
+
+        $this->assertInstanceOf(UnitConverterInterface::class, $unitConverter);
+    }
+}