Code coverage for custom health checks

Author: naman-sriv

microservices-self-registration/contextservice/src/test/java/com/learning/contextservice/myCustomHealthCheckTest.java

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+package com.learning.contextservice;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.test.util.ReflectionTestUtils;
+import org.springframework.boot.actuate.health.Status;
+
+import java.util.function.BooleanSupplier;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class MyCustomHealthCheckTest {
+
+  @Test
+  void testHealthUp() {
+    MyCustomHealthCheck healthCheck = new MyCustomHealthCheck();
+    // Simulate a healthy state
+    ReflectionTestUtils.setField(healthCheck, "isHealthy", true);
+    Health health = healthCheck.health();
+    assertEquals(Status.UP, health.getStatus());
+    assertTrue(health.getDetails().containsKey("message"));
+    assertEquals("Service is running and scheduled checks are OK", health.getDetails().get("message"));
+  }
+
+  @Test
+  void testHealthDown() {
+    MyCustomHealthCheck healthCheck = new MyCustomHealthCheck();
+    // Simulate an unhealthy state
+    ReflectionTestUtils.setField(healthCheck, "isHealthy", false);
+    Health health = healthCheck.health();
+    assertEquals(Status.DOWN, health.getStatus());
+    assertTrue(health.getDetails().containsKey("error"));
+    assertEquals("Scheduled health checks failed", health.getDetails().get("error"));
+  }
+
+  @Test
+  void testUpdateHealthStatusSetsIsHealthy() throws Exception {
+    MyCustomHealthCheck healthCheck = new MyCustomHealthCheck();
+
+    // Force performHealthCheck to return true (by time simulation - might be flaky)
+    long currentTimeForTrue = System.currentTimeMillis();
+    while (currentTimeForTrue % 10000 >= 5000) {
+      Thread.sleep(10); // Wait until time is in the "true" range
+      currentTimeForTrue = System.currentTimeMillis();
+    }
+    ReflectionTestUtils.invokeMethod(healthCheck, "performHealthCheck");
+    healthCheck.updateHealthStatus();
+    assertTrue((Boolean) ReflectionTestUtils.getField(healthCheck, "isHealthy"), "Health should be true");
+
+    // Force performHealthCheck to return false (by time simulation - might be flaky)
+    long currentTimeForFalse = System.currentTimeMillis();
+    while (currentTimeForFalse % 10000 < 5000) {
+      Thread.sleep(10); // Wait until time is in the "false" range
+      currentTimeForFalse = System.currentTimeMillis();
+    }
+    ReflectionTestUtils.invokeMethod(healthCheck, "performHealthCheck");
+    healthCheck.updateHealthStatus();
+    assertFalse((Boolean) ReflectionTestUtils.getField(healthCheck, "isHealthy"), "Health should be false");
+  }
+
+  // Note: Directly testing performHealthCheck (the private method) based on time is inherently
+  // difficult and can lead to flaky tests. The testUpdateHealthStatus attempts to indirectly
+  // verify its behavior. For more robust testing of performHealthCheck in isolation,
+  // you might consider refactoring the class to make the time dependency injectable
+  // or making the method protected for testing purposes.
+}

microservices-self-registration/greetingservice/src/test/java/com/learning/greetingservice/MyCustomHealthCheckTest.java

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+package com.learning.greetingservice;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.actuate.health.Health;
+import org.springframework.test.util.ReflectionTestUtils;
+import org.springframework.boot.actuate.health.Status;
+
+import java.util.function.BooleanSupplier;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class MyCustomHealthCheckTest {
+
+  @Test
+  void testHealthUp() {
+    MyCustomHealthCheck healthCheck = new MyCustomHealthCheck();
+    // Simulate a healthy state
+    ReflectionTestUtils.setField(healthCheck, "isHealthy", true);
+    Health health = healthCheck.health();
+    assertEquals(Status.UP, health.getStatus());
+    assertTrue(health.getDetails().containsKey("message"));
+    assertEquals("Service is running and scheduled checks are OK", health.getDetails().get("message"));
+  }
+
+  @Test
+  void testHealthDown() {
+    MyCustomHealthCheck healthCheck = new MyCustomHealthCheck();
+    // Simulate an unhealthy state
+    ReflectionTestUtils.setField(healthCheck, "isHealthy", false);
+    Health health = healthCheck.health();
+    assertEquals(Status.DOWN, health.getStatus());
+    assertTrue(health.getDetails().containsKey("error"));
+    assertEquals("Scheduled health checks failed", health.getDetails().get("error"));
+  }
+
+  @Test
+  void testUpdateHealthStatusSetsIsHealthy() throws Exception {
+    MyCustomHealthCheck healthCheck = new MyCustomHealthCheck();
+
+    // Force performHealthCheck to return true (by time simulation - might be flaky)
+    long currentTimeForTrue = System.currentTimeMillis();
+    while (currentTimeForTrue % 10000 >= 5000) {
+      Thread.sleep(10); // Wait until time is in the "true" range
+      currentTimeForTrue = System.currentTimeMillis();
+    }
+    ReflectionTestUtils.invokeMethod(healthCheck, "performHealthCheck");
+    healthCheck.updateHealthStatus();
+    assertTrue((Boolean) ReflectionTestUtils.getField(healthCheck, "isHealthy"), "Health should be true");
+
+    // Force performHealthCheck to return false (by time simulation - might be flaky)
+    long currentTimeForFalse = System.currentTimeMillis();
+    while (currentTimeForFalse % 10000 < 5000) {
+      Thread.sleep(10); // Wait until time is in the "false" range
+      currentTimeForFalse = System.currentTimeMillis();
+    }
+    ReflectionTestUtils.invokeMethod(healthCheck, "performHealthCheck");
+    healthCheck.updateHealthStatus();
+    assertFalse((Boolean) ReflectionTestUtils.getField(healthCheck, "isHealthy"), "Health should be false");
+  }
+
+  // Note: Directly testing performHealthCheck (the private method) based on time is inherently
+  // difficult and can lead to flaky tests. The testUpdateHealthStatus attempts to indirectly
+  // verify its behavior. For more robust testing of performHealthCheck in isolation,
+  // you might consider refactoring the class to make the time dependency injectable
+  // or making the method protected for testing purposes.
+}