Add unit tests for com.alibaba.csp.sentinel.util (alibaba#651)

* Add unit test for com.alibaba.csp.sentinel.util.IdUtil
* Add unit tests for com.alibaba.csp.sentinel.util.StringUtil

sentinel-core/src/test/java/com/alibaba/csp/sentinel/util/IdUtilTest.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 1999-2019 Alibaba Group Holding Ltd.
+ *
+ * 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.alibaba.csp.sentinel.util;
+
+import static org.junit.Assert.assertEquals;
+import org.junit.Test;
+
+public class IdUtilTest {
+
+  @Test
+  public void truncate() {
+        assertEquals("(foo),(bar),(baz)", IdUtil.truncate(".(foo).,(bar).,(baz)"));
+  }
+}

sentinel-core/src/test/java/com/alibaba/csp/sentinel/util/StringUtilTest.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 1999-2019 Alibaba Group Holding Ltd.
+ *
+ * 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.alibaba.csp.sentinel.util;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class StringUtilTest {
+
+  @Test
+  public void testCapitalize() {
+    Assert.assertNull(StringUtil.capitalize(null));
+    Assert.assertEquals("Foo", StringUtil.capitalize("foo"));
+  }
+
+  @Test
+  public void testEqualsIgnoreCase() {
+    Assert.assertFalse(StringUtil.equalsIgnoreCase("", "BCCC"));
+    Assert.assertFalse(StringUtil.equalsIgnoreCase(null, ""));
+    Assert.assertTrue(StringUtil.equalsIgnoreCase("", ""));
+    Assert.assertTrue(StringUtil.equalsIgnoreCase("BcCc", "BCCC"));
+    Assert.assertTrue(StringUtil.equalsIgnoreCase(null, null));
+  }
+
+  @Test
+  public void testEquals() {
+    Assert.assertFalse(StringUtil.equals(null, ""));
+    Assert.assertFalse(StringUtil.equals("\"", "\"#\"\"\"\"\"\""));
+    Assert.assertTrue(StringUtil.equals(null, null));
+  }
+
+  @Test
+  public void testIsBlank() {
+    Assert.assertFalse(StringUtil.isBlank("!!!!"));
+    Assert.assertTrue(StringUtil.isBlank(null));
+    Assert.assertTrue(StringUtil.isBlank("\n\n"));
+    Assert.assertTrue(StringUtil.isBlank(""));
+  }
+
+  @Test
+  public void testIsEmpty() {
+    Assert.assertFalse(StringUtil.isEmpty("bar"));
+    Assert.assertTrue(StringUtil.isEmpty(""));
+  }
+
+  @Test
+  public void testIsNotBlank() {
+    Assert.assertFalse(StringUtil.isNotBlank(""));
+    Assert.assertTrue(StringUtil.isNotBlank("\"###"));
+  }
+
+  @Test
+  public void testIsNotEmpty() {
+    Assert.assertFalse(StringUtil.isNotEmpty(""));
+    Assert.assertTrue(StringUtil.isNotEmpty("foo"));
+  }
+
+  @Test
+  public void testTrim() {
+    Assert.assertNull(StringUtil.trim(null));
+    Assert.assertEquals("", StringUtil.trim(""));
+    Assert.assertEquals("foo", StringUtil.trim("foo  "));
+  }
+
+  @Test
+  public void testTrimToEmpty() {
+    Assert.assertEquals("", StringUtil.trimToEmpty(""));
+    Assert.assertEquals("", StringUtil.trimToEmpty(null));
+  }
+
+}