added second test for readConfig & productive code

src/main/java/BordComputer.java

@@ -12,6 +12,7 @@ public class BordComputer {
             properties.load(reader);
             String[] values = properties.values().toArray(new String[0]);
             deviceNames = new String[values.length];
+            System.arraycopy(values, 0, deviceNames, 0, properties.size());
         } catch (Exception e) {
             e.printStackTrace();
         }

src/test/java/BordComputerTest.java

@@ -15,7 +15,7 @@ class BordComputerTest {
 
     @ParameterizedTest
     @MethodSource("readConfigOptions")
-    void readConfigTest(String testName, String testTyp, BordComputer testBc) {
+    void readConfigTest(String testName, String testTyp, BordComputer testBc, String expectedResult) {
         if (testTyp.equals("count")) {
             int count = 0;
             try (FileReader reader = new FileReader("Geraete.config")) {
@@ -27,6 +27,9 @@ class BordComputerTest {
             }
             assertThat(count).describedAs(testName).isEqualTo(testBc.deviceNames.length);
         }
+        if (testTyp.equals("item1")) {
+            assertThat(testBc.deviceNames[0]).describedAs(testName).isEqualTo(expectedResult);
+        }
     }
 
     static Stream<Arguments> readConfigOptions() {
@@ -34,7 +37,8 @@ class BordComputerTest {
         bc1.readConfig();
 
         return Stream.of(
-                Arguments.of("Check if file reader is getting every item in Geraete.config", "count", bc1)
+                Arguments.of("Check if file reader is getting every item in Geraete.config", "count", bc1, ""),
+                Arguments.of("Check if file reader is getting the first element", "item1", bc1, "device.cdPlayer.CdPlayer")
         );
     }