Add unit test for logging/TokenBucket (#1504)

Signed-off-by: yunfeiyanggzq <yunfeiyang@buaa.edu.cn>

sentinel-core/src/test/java/com/alibaba/csp/sentinel/eagleeye/TokenBucketTest.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 1999-2018 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.eagleeye;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.concurrent.TimeUnit;
+
+public class TokenBucketTest {
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testTokenBucketFailToken() {
+        TokenBucket tokenBucket = new TokenBucket(-1, TimeUnit.SECONDS.toMillis(10));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testTokenBucketFailTime() {
+        TokenBucket tokenBucket = new TokenBucket(10, 10);
+    }
+
+    @Test
+    public void testAccept() {
+        TokenBucket tokenBucket = new TokenBucket(1, TimeUnit.SECONDS.toMillis(10));
+        Assert.assertTrue(tokenBucket.accept(System.currentTimeMillis()));
+        Assert.assertFalse(tokenBucket.accept(System.currentTimeMillis()));
+    }
+}