chore: resolve a bunch of linter warnings, no logic changes

src/main/java/io/getunleash/DefaultUnleash.java

@@ -8,7 +8,6 @@
 import io.getunleash.event.IsEnabledImpressionEvent;
 import io.getunleash.event.ToggleEvaluated;
 import io.getunleash.event.VariantImpressionEvent;
-import io.getunleash.metric.UnleashMetricService;
 import io.getunleash.repository.FeatureRepository;
 import io.getunleash.repository.YggdrasilAdapters;
 import io.getunleash.strategy.*;
@@ -27,7 +26,6 @@ public class DefaultUnleash implements Unleash {
 
     private static ConcurrentHashMap<String, LongAdder> initCounts = new ConcurrentHashMap<>();
 
-    private final UnleashMetricService metricService;
     private final FeatureRepository featureRepository;
     private final UnleashContextProvider contextProvider;
     private final EventDispatcher eventDispatcher;
@@ -69,7 +67,6 @@ public DefaultUnleash(
 
         this.config = unleashConfig;
         this.featureRepository = engineProxy;
-        this.metricService = engineProxy;
         this.contextProvider = contextProvider;
         this.eventDispatcher = eventDispatcher;
         initCounts.compute(

src/main/java/io/getunleash/metric/UnleashMetricServiceImpl.java

@@ -8,11 +8,8 @@
 import java.time.LocalDateTime;
 import java.time.ZoneId;
 import java.util.Set;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 public class UnleashMetricServiceImpl implements UnleashMetricService {
-    private static final Logger LOGGER = LoggerFactory.getLogger(UnleashMetricServiceImpl.class);
     private final LocalDateTime started;
     private final UnleashConfig unleashConfig;
     private final MetricSender metricSender;

src/main/java/io/getunleash/util/UnleashScheduledExecutorImpl.java

@@ -48,7 +48,11 @@ public void setInterval(Runnable command, long initialDelaySec, long periodSec)
 
     @Override
     public Future<Void> scheduleOnce(Runnable runnable) {
-        return (Future<Void>) executorService.submit(runnable);
+        return executorService.submit(
+                () -> {
+                    runnable.run();
+                    return null;
+                });
     }
 
     @Override

src/test/java/io/getunleash/DefaultUnleashTest.java

@@ -23,9 +23,7 @@
 import io.getunleash.util.UnleashConfig;
 import java.net.URI;
 import java.net.URISyntaxException;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 import java.util.Optional;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -56,7 +54,6 @@ public void setup() {
         UnleashConfig unleashConfig =
                 UnleashConfig.builder().unleashAPI("http://fakeAPI").appName("fakeApp").build();
         engineProxy = mock(EngineProxy.class);
-        Map<String, Strategy> strategyMap = new HashMap<>();
         contextProvider = mock(UnleashContextProvider.class);
         eventDispatcher = mock(EventDispatcher.class);
 
@@ -145,7 +142,7 @@ public void not_setting_current_time_falls_back_to_correct_now_instant() {
 
     @Test
     public void multiple_instantiations_of_the_same_config_gives_errors() {
-        ListAppender<ILoggingEvent> appender = new ListAppender();
+        ListAppender<ILoggingEvent> appender = new ListAppender<>();
         appender.start();
         Logger unleashLogger = (Logger) LoggerFactory.getLogger(DefaultUnleash.class);
         unleashLogger.addAppender(appender);
@@ -158,13 +155,13 @@ public void multiple_instantiations_of_the_same_config_gives_errors() {
                         .apiKey("default:development:1234567890123456")
                         .instanceId(instanceId)
                         .build();
-        Unleash unleash1 = new DefaultUnleash(config);
+        new DefaultUnleash(config);
         // We've only instantiated the client once, so no errors should've been logged
         assertThat(appender.list).isEmpty();
-        Unleash unleash2 = new DefaultUnleash(config);
+        new DefaultUnleash(config);
         // We've now instantiated the client twice, so we expect an error log line.
         assertThat(appender.list).hasSize(1);
-        String id = config.getClientIdentifier();
+        config.getClientIdentifier();
         assertThat(appender.list)
                 .extracting(ILoggingEvent::getFormattedMessage)
                 .containsExactly(
@@ -174,7 +171,7 @@ public void multiple_instantiations_of_the_same_config_gives_errors() {
                                 + instanceId
                                 + "] running. Please double check your code where you are instantiating the Unleash SDK");
         appender.list.clear();
-        Unleash unleash3 = new DefaultUnleash(config);
+        new DefaultUnleash(config);
         // We've now instantiated the client twice, so we expect an error log line.
         assertThat(appender.list).hasSize(1);
         assertThat(appender.list)
@@ -197,10 +194,10 @@ public void supports_failing_hard_on_multiple_instantiations() {
                         .instanceId("multiple_connection_exception")
                         .build();
         String id = config.getClientIdentifier();
-        Unleash unleash1 = new DefaultUnleash(config);
+        new DefaultUnleash(config);
         assertThatThrownBy(
                         () -> {
-                            Unleash unleash2 = new DefaultUnleash(config, null, null, null, true);
+                            new DefaultUnleash(config, null, null, null, true);
                         })
                 .isInstanceOf(RuntimeException.class)
                 .withFailMessage(
@@ -294,7 +291,7 @@ public void asynchronous_fetch_on_initialisation_fails_silently_and_retries()
                         .unleashFeatureFetcherFactory((UnleashConfig c) -> fetcher)
                         .build();
 
-        Unleash unleash = new DefaultUnleash(config);
+        new DefaultUnleash(config);
         Thread.sleep(1);
         verify(fetcher, times(1)).fetchFeatures();
         Thread.sleep(1200);

src/test/java/io/getunleash/SynchronousTestExecutor.java

@@ -20,7 +20,7 @@ public void setInterval(Runnable command, long initialDelaySec, long periodSec)
     }
 
     @Override
-    public ScheduledFuture scheduleOnce(Runnable runnable) {
+    public ScheduledFuture<Void> scheduleOnce(Runnable runnable) {
         runnable.run();
         return new AlreadyCompletedScheduledFuture();
     }

src/test/java/io/getunleash/UnleashTest.java

@@ -59,6 +59,7 @@ public void fallback_function_should_be_invoked_and_return_true() {
                 .thenReturn(new FlatResponse<Boolean>(false, null));
         Unleash unleash = new DefaultUnleash(baseConfig, engineProxy);
 
+        @SuppressWarnings("unchecked")
         BiPredicate<String, UnleashContext> fallbackAction = mock(BiPredicate.class);
         when(fallbackAction.test(eq("test"), any(UnleashContext.class))).thenReturn(true);
 
@@ -73,6 +74,7 @@ public void fallback_function_should_be_invoked_also_with_context() {
                 .thenReturn(new FlatResponse<Boolean>(false, null));
         Unleash unleash = new DefaultUnleash(baseConfig, engineProxy);
 
+        @SuppressWarnings("unchecked")
         BiPredicate<String, UnleashContext> fallbackAction = mock(BiPredicate.class);
         when(fallbackAction.test(eq("test"), any(UnleashContext.class))).thenReturn(true);
 
@@ -89,6 +91,7 @@ void fallback_function_should_be_invoked_and_return_false() {
                 .thenReturn(new FlatResponse<Boolean>(false, null));
         Unleash unleash = new DefaultUnleash(baseConfig, engineProxy);
 
+        @SuppressWarnings("unchecked")
         BiPredicate<String, UnleashContext> fallbackAction = mock(BiPredicate.class);
         when(fallbackAction.test(eq("test"), any(UnleashContext.class))).thenReturn(false);
 
@@ -103,6 +106,7 @@ void fallback_function_should_not_be_called_when_toggle_is_defined() {
                 .thenReturn(new FlatResponse<Boolean>(true, true));
         Unleash unleash = new DefaultUnleash(baseConfig, engineProxy);
 
+        @SuppressWarnings("unchecked")
         BiPredicate<String, UnleashContext> fallbackAction = mock(BiPredicate.class);
         when(fallbackAction.test(eq("test"), any(UnleashContext.class))).thenReturn(false);
 

src/test/java/io/getunleash/metric/UnleashMetricServiceImplTest.java

@@ -28,8 +28,8 @@ public void should_register_future_for_sending_interval_regualry() {
                         .unleashAPI("http://unleash.com")
                         .build();
         UnleashScheduledExecutor executor = mock(UnleashScheduledExecutor.class);
-        UnleashMetricService unleashMetricService =
-                new UnleashMetricServiceImpl(config, executor, null);
+
+        new UnleashMetricServiceImpl(config, executor, null);
 
         verify(executor, times(1)).setInterval(any(Runnable.class), eq(interval), eq(interval));
     }
@@ -106,8 +106,7 @@ public void should_send_metrics() {
         DefaultHttpMetricsSender sender = mock(DefaultHttpMetricsSender.class);
         UnleashEngine engine = new UnleashEngine();
 
-        UnleashMetricService unleashMetricService =
-                new UnleashMetricServiceImpl(config, sender, executor, engine);
+        new UnleashMetricServiceImpl(config, sender, executor, engine);
 
         ArgumentCaptor<Runnable> sendMetricsCallback = ArgumentCaptor.forClass(Runnable.class);
         verify(executor).setInterval(sendMetricsCallback.capture(), anyLong(), anyLong());
@@ -131,8 +130,7 @@ public void should_record_and_send_metrics()
         DefaultHttpMetricsSender sender = mock(DefaultHttpMetricsSender.class);
         UnleashEngine engine = new UnleashEngine();
 
-        UnleashMetricService unleashMetricService =
-                new UnleashMetricServiceImpl(config, sender, executor, engine);
+        new UnleashMetricServiceImpl(config, sender, executor, engine);
 
         engine.isEnabled("someToggle", new Context());
         engine.isEnabled("someToggle", new Context());
@@ -374,8 +372,7 @@ public void should_add_new_metrics_data_to_bucket() {
         DefaultHttpMetricsSender sender = mock(DefaultHttpMetricsSender.class);
         UnleashEngine engine = new UnleashEngine();
 
-        UnleashMetricService unleashMetricService =
-                new UnleashMetricServiceImpl(config, sender, executor, engine);
+        new UnleashMetricServiceImpl(config, sender, executor, engine);
 
         ArgumentCaptor<Runnable> sendMetricsCallback = ArgumentCaptor.forClass(Runnable.class);
         verify(executor).setInterval(sendMetricsCallback.capture(), anyLong(), anyLong());

src/test/java/io/getunleash/repository/FeatureRepositoryTest.java

@@ -10,7 +10,6 @@
 
 import io.getunleash.DefaultUnleash;
 import io.getunleash.FeatureDefinition;
-import io.getunleash.Unleash;
 import io.getunleash.engine.UnleashEngine;
 import io.getunleash.event.ClientFeaturesResponse;
 import io.getunleash.streaming.StreamingFeatureFetcher;
@@ -147,14 +146,13 @@ public void should_perform_synchronous_fetch_on_initialisation() {
                 ClientFeaturesResponse.updated(loadMockFeatures("unleash-repo-v2.json"));
         when(fetcher.fetchFeatures()).thenReturn(response);
 
-        FeatureRepository featureRepository =
-                new FeatureRepositoryImpl(
-                        config,
-                        backupHandler,
-                        new UnleashEngine(),
-                        fetcher,
-                        streamingFetcher,
-                        bootstrapHandler);
+        new FeatureRepositoryImpl(
+                config,
+                backupHandler,
+                new UnleashEngine(),
+                fetcher,
+                streamingFetcher,
+                bootstrapHandler);
 
         verify(fetcher, times(1)).fetchFeatures();
     }
@@ -171,14 +169,13 @@ public void should_not_perform_synchronous_fetch_on_initialisation() {
 
         when(fetcher.fetchFeatures()).thenReturn(response);
 
-        FeatureRepositoryImpl featureRepository =
-                new FeatureRepositoryImpl(
-                        config,
-                        backupHandler,
-                        new UnleashEngine(),
-                        fetcher,
-                        streamingFetcher,
-                        bootstrapHandler);
+        new FeatureRepositoryImpl(
+                config,
+                backupHandler,
+                new UnleashEngine(),
+                fetcher,
+                streamingFetcher,
+                bootstrapHandler);
 
         verify(fetcher, times(0)).fetchFeatures();
     }
@@ -233,14 +230,13 @@ public void should_not_read_bootstrap_if_backup_was_found() {
         UnleashConfig config =
                 defaultConfigBuilder().toggleBootstrapProvider(bootstrapHandler).build();
 
-        FeatureRepositoryImpl featureRepository =
-                new FeatureRepositoryImpl(
-                        config,
-                        backupHandler,
-                        new UnleashEngine(),
-                        fetcher,
-                        streamingFetcher,
-                        bootstrapHandler);
+        new FeatureRepositoryImpl(
+                config,
+                backupHandler,
+                new UnleashEngine(),
+                fetcher,
+                streamingFetcher,
+                bootstrapHandler);
 
         verify(bootstrapHandler, times(0)).read();
     }
@@ -263,7 +259,7 @@ public void shouldCallStartupExceptionHandlerIfStartupFails() {
                         .toggleBootstrapProvider(toggleBootstrapProvider)
                         .build();
 
-        Unleash unleash = new DefaultUnleash(config);
+        new DefaultUnleash(config);
         assertThat(failed).isTrue();
     }
 

src/test/java/io/getunleash/repository/OkHttpFeatureFetcherTest.java

@@ -245,7 +245,7 @@ public void should_not_set_empty_ifNoneMatchHeader() throws URISyntaxException {
         URI uri = new URI("http://localhost:" + serverMock.getPort() + "/api/");
         UnleashConfig config = UnleashConfig.builder().appName("test").unleashAPI(uri).build();
         OkHttpFeatureFetcher okHttpToggleFetcher = new OkHttpFeatureFetcher(config);
-        ClientFeaturesResponse response = okHttpToggleFetcher.fetchFeatures();
+        okHttpToggleFetcher.fetchFeatures();
 
         verify(getRequestedFor(urlMatching("/api/client/features")).withoutHeader("If-None-Match"));
     }
@@ -265,7 +265,7 @@ public void should_add_project_filter_to_toggles_url_if_config_has_it_set()
         UnleashConfig config =
                 UnleashConfig.builder().appName("test").unleashAPI(uri).projectName("name").build();
         OkHttpFeatureFetcher okHttpFeatureFetcher = new OkHttpFeatureFetcher(config);
-        ClientFeaturesResponse response = okHttpFeatureFetcher.fetchFeatures();
+        okHttpFeatureFetcher.fetchFeatures();
         verify(getRequestedFor(urlMatching("/api/client/features\\?project=name")));
     }
 

src/test/java/io/getunleash/streaming/StreamingFeatureFetchingTest.java

@@ -1,4 +1,4 @@
-package io.getunleash.integration;
+package io.getunleash.streaming;
 
 import static com.github.tomakehurst.wiremock.client.WireMock.*;
 import static com.github.tomakehurst.wiremock.core.WireMockConfiguration.wireMockConfig;

src/test/java/io/getunleash/util/UnleashConfigTest.java

@@ -189,7 +189,7 @@ public void should_add_custom_headers_from_provider_to_connection_if_present()
             throws IOException {
         String unleashAPI = "http://unleash.org";
         Map<String, String> result =
-                new HashMap() {
+                new HashMap<String, String>() {
                     {
                         put("PROVIDER-HEADER", "Provider Value");
                     }