Merge PR #380: [WIP] Update gcp-auth-extension module to follow style guide

Author: trask

gcp-auth-extension/src/main/java/io/opentelemetry/contrib/gcp/auth/ConfigurableOption.java

@@ -5,9 +5,10 @@
 
 package io.opentelemetry.contrib.gcp.auth;
 
+import static java.util.Locale.ROOT;
+
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigurationException;
-import java.util.Locale;
 import java.util.Optional;
 import java.util.function.Supplier;
 
@@ -61,7 +62,7 @@ enum ConfigurableOption {
     this.userReadableName = userReadableName;
     this.environmentVariableName = this.name();
     this.systemPropertyName =
-        this.environmentVariableName.toLowerCase(Locale.ROOT).replace('_', '.');
+        this.environmentVariableName.toLowerCase(ROOT).replace('_', '.');
   }
 
   /**

gcp-auth-extension/src/main/java/io/opentelemetry/contrib/gcp/auth/GcpAuthAutoConfigurationCustomizerProvider.java

@@ -5,9 +5,14 @@
 
 package io.opentelemetry.contrib.gcp.auth;
 
+import static io.opentelemetry.api.common.AttributeKey.stringKey;
+import static java.util.Arrays.stream;
+import static java.util.Objects.nonNull;
+import static java.util.stream.Collectors.joining;
+import static java.util.stream.Collectors.toMap;
+
 import com.google.auth.oauth2.GoogleCredentials;
 import com.google.auto.service.AutoService;
-import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.contrib.gcp.auth.GoogleAuthException.Reason;
 import io.opentelemetry.exporter.otlp.http.metrics.OtlpHttpMetricExporter;
@@ -25,14 +30,11 @@
 import io.opentelemetry.sdk.resources.Resource;
 import io.opentelemetry.sdk.trace.export.SpanExporter;
 import java.io.IOException;
-import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Optional;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import java.util.stream.Collectors;
 import javax.annotation.Nonnull;
 
 /**
@@ -150,7 +152,7 @@ private static boolean isSignalTargeted(String checkSignal, ConfigProperties con
     String userSpecifiedTargetedSignals =
         ConfigurableOption.GOOGLE_OTEL_AUTH_TARGET_SIGNALS.getConfiguredValueWithFallback(
             configProperties, () -> SIGNAL_TYPE_ALL);
-    return Arrays.stream(userSpecifiedTargetedSignals.split(","))
+    return stream(userSpecifiedTargetedSignals.split(","))
         .map(String::trim)
         .anyMatch(
             targetedSignal ->
@@ -202,17 +204,16 @@ private static Map<String, String> getRequiredHeaderMap(
     } catch (IOException e) {
       throw new GoogleAuthException(Reason.FAILED_ADC_REFRESH, e);
     }
-    // flatten list
     Map<String, String> flattenedHeaders =
         gcpHeaders.entrySet().stream()
             .collect(
-                Collectors.toMap(
+                toMap(
                     Map.Entry::getKey,
                     entry ->
                         entry.getValue().stream()
-                            .filter(Objects::nonNull) // Filter nulls
+                            .filter(nonNull) // Filter nulls
                             .filter(s -> !s.isEmpty()) // Filter empty strings
-                            .collect(Collectors.joining(","))));
+                            .collect(joining(","))));
     // Add quota user project header if not detected by the auth library and user provided it via
     // system properties.
     if (!flattenedHeaders.containsKey(QUOTA_USER_PROJECT_HEADER)) {
@@ -232,7 +233,7 @@ private static Resource customizeResource(Resource resource, ConfigProperties co
         ConfigurableOption.GOOGLE_CLOUD_PROJECT.getConfiguredValue(configProperties);
     Resource res =
         Resource.create(
-            Attributes.of(AttributeKey.stringKey(GCP_USER_PROJECT_ID_KEY), gcpProjectId));
+            Attributes.of(stringKey(GCP_USER_PROJECT_ID_KEY), gcpProjectId));
     return resource.merge(res);
   }
 }

gcp-auth-extension/src/main/java/io/opentelemetry/contrib/gcp/auth/GoogleAuthException.java

@@ -10,7 +10,7 @@
  * thrown when there are issues with retrieving or refreshing Google Application Default Credentials
  * (ADC).
  */
-public class GoogleAuthException extends RuntimeException {
+public final class GoogleAuthException extends RuntimeException {
 
   private static final long serialVersionUID = 149908685226796448L;
 

gcp-auth-extension/src/test/java/io/opentelemetry/contrib/gcp/auth/GcpAuthAutoConfigurationCustomizerProviderTest.java

@@ -10,10 +10,17 @@
 import static io.opentelemetry.contrib.gcp.auth.GcpAuthAutoConfigurationCustomizerProvider.SIGNAL_TYPE_ALL;
 import static io.opentelemetry.contrib.gcp.auth.GcpAuthAutoConfigurationCustomizerProvider.SIGNAL_TYPE_METRICS;
 import static io.opentelemetry.contrib.gcp.auth.GcpAuthAutoConfigurationCustomizerProvider.SIGNAL_TYPE_TRACES;
+import static java.util.Collections.emptyMap;
+import static java.util.Collections.singletonList;
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 import com.google.auth.oauth2.AccessToken;
 import com.google.auth.oauth2.GoogleCredentials;
@@ -135,15 +142,15 @@ public void testTraceCustomizerOtlpHttp() {
         ConfigurableOption.GOOGLE_OTEL_AUTH_TARGET_SIGNALS.getSystemProperty(), SIGNAL_TYPE_TRACES);
     // Prepare mocks
     prepareMockBehaviorForGoogleCredentials();
-    OtlpHttpSpanExporter mockOtlpHttpSpanExporter = Mockito.mock(OtlpHttpSpanExporter.class);
+    OtlpHttpSpanExporter mockOtlpHttpSpanExporter = mock(OtlpHttpSpanExporter.class);
     OtlpHttpSpanExporterBuilder otlpSpanExporterBuilder = OtlpHttpSpanExporter.builder();
     OtlpHttpSpanExporterBuilder spyOtlpHttpSpanExporterBuilder =
         Mockito.spy(otlpSpanExporterBuilder);
-    Mockito.when(spyOtlpHttpSpanExporterBuilder.build()).thenReturn(mockOtlpHttpSpanExporter);
+    when(spyOtlpHttpSpanExporterBuilder.build()).thenReturn(mockOtlpHttpSpanExporter);
 
-    Mockito.when(mockOtlpHttpSpanExporter.shutdown()).thenReturn(CompletableResultCode.ofSuccess());
+    when(mockOtlpHttpSpanExporter.shutdown()).thenReturn(CompletableResultCode.ofSuccess());
     List<SpanData> exportedSpans = new ArrayList<>();
-    Mockito.when(mockOtlpHttpSpanExporter.export(Mockito.anyCollection()))
+    when(mockOtlpHttpSpanExporter.export(any()))
         .thenAnswer(
             invocationOnMock -> {
               exportedSpans.addAll(invocationOnMock.getArgument(0));