#1510 Improvments done in Circuit Breaker

circuit-breaker/src/test/java/com/iluwatar/circuitbreaker/DefaultCircuitBreakerTest.java

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+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.circuitbreaker;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.rmi.Remote;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Circuit Breaker test
+ */
+public class DefaultCircuitBreakerTest {
+
+  //long timeout, int failureThreshold, long retryTimePeriod
+  @Test
+  public void testEvaluateState() {
+    var circuitBreaker = new DefaultCircuitBreaker(null, 1, 1, 100);
+    //Right now, failureCount<failureThreshold, so state should be closed
+    assertEquals(circuitBreaker.getState(), "CLOSED");
+    circuitBreaker.failureCount = 4;
+    circuitBreaker.lastFailureTime = System.nanoTime();
+    circuitBreaker.evaluateState();
+    //Since failureCount>failureThreshold, and lastFailureTime is nearly equal to current time,
+    //state should be half-open
+    assertEquals(circuitBreaker.getState(), "HALF_OPEN");
+    //Since failureCount>failureThreshold, and lastFailureTime is much lesser current time,
+    //state should be open
+    circuitBreaker.lastFailureTime = System.nanoTime() - 1000 * 1000 * 1000 * 1000;
+    circuitBreaker.evaluateState();
+    assertEquals(circuitBreaker.getState(), "OPEN");
+    //Now set it back again to closed to test idempotency
+    circuitBreaker.failureCount = 0;
+    circuitBreaker.evaluateState();
+    assertEquals(circuitBreaker.getState(), "CLOSED");
+  }
+
+  @Test
+  public void testSetStateForBypass() {
+    var circuitBreaker = new DefaultCircuitBreaker(null, 1, 1, 2000 * 1000 * 1000);
+    //Right now, failureCount<failureThreshold, so state should be closed
+    //Bypass it and set it to open
+    circuitBreaker.setState(State.OPEN);
+    assertEquals(circuitBreaker.getState(), "OPEN");
+  }
+
+  @Test
+  public void testApiResponses() throws RemoteServiceException {
+    RemoteService mockService = new RemoteService() {
+      @Override
+      public String call() throws RemoteServiceException {
+        return "Remote Success";
+      }
+    };
+    var circuitBreaker = new DefaultCircuitBreaker(mockService, 1, 1, 100);
+    //Call with the paramater start_time set to huge amount of time in past so that service
+    //replies with "Ok". Also, state is CLOSED in start
+    var serviceStartTime = System.nanoTime() - 60 * 1000 * 1000 * 1000;
+    var response = circuitBreaker.attemptRequest();
+    assertEquals(response, "Remote Success");
+
+  }
+}