test(conf): add test for FusionConfiguration

src/test/java/com/zdjizhi/flink/voip/conf/FusionConfigurationTest.java

@@ -0,0 +1,67 @@
+package com.zdjizhi.flink.voip.conf;
+
+import org.apache.flink.configuration.Configuration;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.Properties;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class FusionConfigurationTest {
+
+    private FusionConfiguration fusionConfiguration;
+
+    @BeforeEach
+    public void setUp() {
+        final Configuration config;
+        config = new Configuration();
+        config.setString("prefix_key1", "value1");
+        config.setString("prefix_key2", "value2");
+        config.setString("other_key", "other_value");
+
+        fusionConfiguration = new FusionConfiguration(config);
+    }
+    
+    @Test
+    public void testGetPropertiesWithValidPrefix() {
+        String prefix = "prefix_";
+        Properties properties = fusionConfiguration.getProperties(prefix);
+
+        assertEquals(2, properties.size());
+        assertEquals("value1", properties.getProperty("key1"));
+        assertEquals("value2", properties.getProperty("key2"));
+    }
+
+    @Test
+    public void testGetPropertiesWithInvalidPrefix() {
+        String prefix = "invalid_";
+        Properties properties = fusionConfiguration.getProperties(prefix);
+
+        assertTrue(properties.isEmpty());
+    }
+
+    @Test
+    public void testGetPropertiesWithEmptyPrefix() {
+        String prefix = "";
+        Properties properties = fusionConfiguration.getProperties(prefix);
+
+        assertEquals(3, properties.size());
+        assertEquals("value1", properties.getProperty("prefix_key1"));
+        assertEquals("value2", properties.getProperty("prefix_key2"));
+        assertEquals("other_value", properties.getProperty("other_key"));
+    }
+
+    @Test
+    public void testGetPropertiesWithNullPrefix() {
+        // Null prefix should be treated as an empty prefix
+        String prefix = null;
+        Properties properties = fusionConfiguration.getProperties(prefix);
+
+        assertEquals(3, properties.size());
+        assertEquals("value1", properties.getProperty("prefix_key1"));
+        assertEquals("value2", properties.getProperty("prefix_key2"));
+        assertEquals("other_value", properties.getProperty("other_key"));
+    }
+}