fix: allow to add multiple single files to the same unit-type (pimlie#16)

* add unittest for pimlie#15

* add fix for pimlie#15

* fix static/shared state between tests

Author: pimlie

src/Map.php

@@ -88,6 +88,8 @@ public static function load()
      */
     protected static function loadPath($path, $namespace = '', $unitType = '')
     {
+        $classes = [];
+
         if (is_file($path)) {
             $classes = self::loadFile($path, $namespace);
 
@@ -98,7 +100,7 @@ protected static function loadPath($path, $namespace = '', $unitType = '')
             $classes = self::loadDirectory($path, $namespace);
         }
 
-        self::$map = self::$map + $classes;
+        self::$map = array_merge_recursive(self::$map, $classes);
 
         return count($classes) > 0;
     }

tests/UnitTest.php

@@ -3,6 +3,7 @@
 
 use PHPUnit\Framework\TestCase;
 use PhpUnitConversion\Exception;
+use PhpUnitConversion\Map\Factor;
 use PhpUnitConversion\Unit;
 use PhpUnitConversion\Map as UnitMap;
 use PhpUnitConversion\Unit\Mass;
@@ -184,4 +185,29 @@ public function testNearestInteger()
 
         $this->assertInstanceOf(Mass\Gram::class, $unit);
     }
+
+    public function testMultipleCustomUnits()
+    {
+        UnitMap::clear();
+        UnitMap::add(__DIR__ . '/../src/Unit/Length/Meter.php', 'PhpUnitConversion\\Unit\\Length', Unit\Length::class);
+        UnitMap::add(__DIR__ . '/../src/Unit/Length/CentiMeter.php', 'PhpUnitConversion\\Unit\\Length', Unit\Length::class);
+
+        UnitMap::add(__DIR__ . '/../src/Unit/Mass/KiloGram.php', 'PhpUnitConversion\\Unit\\Mass', Unit\Mass::class);
+        UnitMap::add(__DIR__ . '/../src/Unit/Mass/Gram.php', 'PhpUnitConversion\\Unit\\Mass', Unit\Mass::class);
+
+        $lengthUnits = Factor::byType(Unit\Length::TYPE);
+        $this->assertCount(2, $lengthUnits);
+        $this->assertArrayHasKey(Unit\Length\CentiMeter::class, $lengthUnits);
+        $this->assertArrayHasKey(Unit\Length\Meter::class, $lengthUnits);
+        $this->assertSame(Unit\Length\CentiMeter::FACTOR, $lengthUnits[Unit\Length\CentiMeter::class]);
+        $this->assertSame(1, $lengthUnits[Unit\Length\Meter::class]);
+
+        $lengthUnits = Factor::byType(Unit\Mass::TYPE);
+        $this->assertCount(2, $lengthUnits);
+        $this->assertArrayHasKey(Unit\Mass\KiloGram::class, $lengthUnits);
+        $this->assertArrayHasKey(Unit\Mass\Gram::class, $lengthUnits);
+        $this->assertSame(Unit\Mass\KiloGram::FACTOR, $lengthUnits[Unit\Mass\KiloGram::class]);
+        $this->assertSame(1, $lengthUnits[Unit\Mass\Gram::class]);
+        UnitMap::add(__DIR__.'/../src/Unit', 'PhpUnitConversion\\Unit', null);
+    }
 }