test(apollo-core): PropertiesUtilTest (#4113)

* Create PropertiesUtilTest.java

* Update apollo-core/src/test/java/com/ctrip/framework/apollo/core/utils/PropertiesUtilTest.java

Co-authored-by: wxq <[email protected]>

* Update PropertiesUtilTest.java

Co-authored-by: wxq <[email protected]>

apollo-core/src/test/java/com/ctrip/framework/apollo/core/utils/PropertiesUtilTest.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2021 Apollo Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+package com.ctrip.framework.apollo.core.utils;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+
+import java.io.IOException;
+import java.util.Properties;
+
+
+public class PropertiesUtilTest {
+
+
+  @Test
+  public void testToString() throws IOException {
+
+    assertEquals("", PropertiesUtil.toString(new Properties()));
+    assertNotEquals(" ", PropertiesUtil.toString(new Properties()));
+
+    Properties properties = new Properties();
+    properties.put("a", "aaa");
+    assertEquals("a=aaa" + System.lineSeparator(), PropertiesUtil.toString(properties));
+  }
+
+  @Test
+  public void testFilterPropertiesComment() {
+
+    StringBuffer sb1 = new StringBuffer(System.lineSeparator());
+    PropertiesUtil.filterPropertiesComment(sb1);
+    boolean equals = "".equals(sb1.toString());
+    assertEquals(false, equals);
+
+    StringBuffer sb2 = new StringBuffer("#aaa" + System.lineSeparator());
+    PropertiesUtil.filterPropertiesComment(sb2);
+    assertEquals("", sb2.toString());
+
+    StringBuffer sb3 = new StringBuffer("#aaaaa" + System.lineSeparator() + "bbb");
+    PropertiesUtil.filterPropertiesComment(sb3);
+    assertEquals("bbb", sb3.toString());
+    assertNotEquals("#aaaaa" + System.lineSeparator() + "bbb", sb3.toString());
+  }
+}