#39 Added some unit tests

src/test/java/de/rwu/easydrop/util/ConfigTest.java

@@ -0,0 +1,86 @@
+package de.rwu.easydrop.util;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.fail;
+import static org.mockito.Mockito.spy;
+
+import java.io.FileInputStream;
+import java.util.NoSuchElementException;
+
+import javax.naming.ConfigurationException;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+class ConfigTest {
+    @Mock
+    private FileInputStream mockFileInputStream;
+
+    private Config config;
+
+    @BeforeEach
+    void setUp() throws ConfigurationException {
+        MockitoAnnotations.openMocks(this);
+        config = spy(Config.getInstance());
+    }
+
+    @Test
+    void testGetProperty_ExistingKey() throws NoSuchElementException {
+        config.setProperty("API_KEY", "12345");
+
+        String value = config.getProperty("API_KEY");
+
+        assertEquals("12345", value);
+    }
+
+    @Test
+    void testGetProperty_NonExistingKey() {
+        assertThrows(NoSuchElementException.class, () -> config.getProperty("NON_EXISTING_KEY"));
+    }
+
+    @Test
+    void testSetProperty() {
+        config.setProperty("API_KEY", "12345");
+
+        assertEquals("12345", config.getProperty("API_KEY"));
+    }
+
+    @Test
+    void testGetInstanceNull() {
+        config = null;
+
+        try {
+            Config newConfig = Config.getInstance();
+            // Check if the returned instance is not null
+            assertNotNull(newConfig);
+        } catch (ConfigurationException e) {
+            fail("ConfigurationException should not be thrown.");
+        }
+    }
+
+    @Test
+    void testGetInstanceNotNull() {
+        try {
+            Config newConfig = Config.getInstance();
+            // Check if the returned instance is not null
+            assertNotNull(newConfig);
+        } catch (ConfigurationException e) {
+            fail("ConfigurationException should not be thrown.");
+        }
+    }
+
+    @Test
+    void testLoadConfigSuccessfully() {
+        try {
+            config.loadConfig();
+            config.setProperty("WHATEVER", "SUCCESS");
+            assertNotNull(config.getProperty("WHATEVER"));
+        } catch (ConfigurationException e) {
+            fail("ConfigurationException should not be thrown");
+        }
+    }
+}