add test for obtain the sat code for tax

src/Taxes/IEPS.php

@@ -6,6 +6,13 @@
 
 class IEPS extends Tax implements TaxContract
 {
+    /**
+     * Code from the SAT Catalog.
+     *
+     * @var string
+     */
+    protected $code = '003';
+
     /**
      * Calculate tax percentage of a given amount.
      *

src/Taxes/ISR.php

@@ -6,6 +6,13 @@
 
 class ISR extends Tax implements TaxContract
 {
+    /**
+     * Code from the SAT Catalog.
+     *
+     * @var string
+     */
+    protected $code = '001';
+
     /**
      * Calculate tax percentage of a given amount.
      *

src/Taxes/IVA.php

@@ -6,6 +6,13 @@
 
 class IVA extends Tax implements TaxContract
 {
+    /**
+     * Code from the SAT Catalog.
+     *
+     * @var string
+     */
+    protected $code = '002';
+
     /**
      * Calculate tax percentage of a given amount.
      *

src/Taxes/Tax.php

@@ -67,6 +67,10 @@ public function __get($property)
             return $this->getTaxName();
         }
 
+        if (property_exists($this, $property)) {
+            return $this->{$property};
+        }
+
         throw new \Exception('Property not exists');
     }
 

tests/TaxTest.php

@@ -68,4 +68,16 @@ public function testCanGetPercentageByType()
         $ieps = new IEPS($retention);
         $this->assertEquals(-0.08, $ieps->percentage());
     }
+
+    public function testCanGetFiscalCode()
+    {
+        $iva = new IVA();
+        $this->assertEquals('002', $iva->code);
+
+        $isr = new ISR();
+        $this->assertEquals('001', $isr->code);
+
+        $ieps = new IEPS();
+        $this->assertEquals('003', $ieps->code);
+    }
 }