Added test for healthcheck error handling

.gitignore

@@ -2,3 +2,6 @@
 /.idea
 /target
 /build
+.project
+.classpath
+.settings/

src/main/java/com/github/arteam/jdbi3/JdbiHealthCheck.java

@@ -16,6 +16,7 @@
  */
 public class JdbiHealthCheck extends HealthCheck {
     private static final Logger log = LoggerFactory.getLogger(JdbiHealthCheck.class);
+    protected static final String VALIDATION_QUERY_FAILED = "Validation query failed";
 
     private final Jdbi jdbi;
     private final String validationQuery;
@@ -35,7 +36,7 @@ protected Result check() throws Exception {
                 return Result.healthy();
             } catch (Exception e) {
                 log.error("jDBI Healthcheck failed. validation-query={}", validationQuery, e);
-                return Result.unhealthy("Validation query failed");
+                return Result.unhealthy(VALIDATION_QUERY_FAILED);
             }
         });
     }

src/test/java/com/github/arteam/jdbi3/HealthCheckTest.java

@@ -0,0 +1,49 @@
+package com.github.arteam.jdbi3;
+
+import com.codahale.metrics.health.HealthCheck.Result;
+import com.google.common.util.concurrent.MoreExecutors;
+import io.dropwizard.util.Duration;
+import org.jdbi.v3.core.Handle;
+import org.jdbi.v3.core.Jdbi;
+import org.jdbi.v3.core.mapper.MappingException;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.junit.MockitoRule;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.when;
+
+public class HealthCheckTest {
+    @Rule
+    public final MockitoRule mockito = MockitoJUnit.rule();
+
+    private JdbiHealthCheck healthCheck;
+    @Mock
+    private Jdbi jdbi;
+    @Mock
+    private Handle h;
+
+    @Before
+    public void init() {
+        when(jdbi.open()).thenReturn(h);
+        healthCheck = new JdbiHealthCheck(
+                MoreExecutors.newDirectExecutorService(),
+                Duration.seconds(5),
+                jdbi,
+                "select 1");
+    }
+
+    @Test
+    public void shouldReturnNotHealthyBecauseOfErrorOnError() throws Exception {
+        when(h.execute("select 1")).thenThrow(new MappingException("bad error here"));
+
+        final Result result = healthCheck.check();
+
+        assertThat(result).isNotNull()
+                .extracting(Result::getMessage)
+                .containsOnly(JdbiHealthCheck.VALIDATION_QUERY_FAILED);
+    }
+}