Add event handlings to "Propagating[Sender|Receiver]TracingObservatinnHandler"

micrometer-tracing-bridges/micrometer-tracing-bridge-brave/src/test/java/io/micrometer/tracing/brave/handler/PropagatingReceiverTracingObservationHandlerBraveTests.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2013-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.micrometer.tracing.brave.handler;
+
+import brave.Tracing;
+import brave.handler.MutableSpan;
+import brave.test.TestSpanHandler;
+import io.micrometer.observation.Observation.Event;
+import io.micrometer.observation.transport.ReceiverContext;
+import io.micrometer.tracing.Tracer;
+import io.micrometer.tracing.brave.bridge.BraveBaggageManager;
+import io.micrometer.tracing.brave.bridge.BraveCurrentTraceContext;
+import io.micrometer.tracing.brave.bridge.BravePropagator;
+import io.micrometer.tracing.brave.bridge.BraveTracer;
+import io.micrometer.tracing.handler.PropagatingReceiverTracingObservationHandler;
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+import java.util.Map;
+
+import static org.assertj.core.api.BDDAssertions.then;
+
+@SuppressWarnings("unchecked")
+class PropagatingReceiverTracingObservationHandlerBraveTests {
+
+    TestSpanHandler testSpanHandler = new TestSpanHandler();
+
+    Tracing tracing = Tracing.newBuilder().addSpanHandler(testSpanHandler).build();
+
+    Tracer tracer = new BraveTracer(tracing.tracer(), new BraveCurrentTraceContext(tracing.currentTraceContext()),
+            new BraveBaggageManager());
+
+    PropagatingReceiverTracingObservationHandler<ReceiverContext<?>> handler = new PropagatingReceiverTracingObservationHandler<>(
+            tracer, new BravePropagator(tracing));
+
+    @Test
+    void should_be_applicable_for_non_null_context() {
+        then(handler.supportsContext(new ReceiverContext<>((carrier, key) -> null))).isTrue();
+    }
+
+    @Test
+    void should_not_be_applicable_for_null_context() {
+        then(handler.supportsContext(null)).isFalse();
+    }
+
+    @Test
+    void should_signal_events() {
+        Event event = Event.of("foo", "bar");
+        ReceiverContext<Object> receiverContext = new ReceiverContext<>((carrier, key) -> "val");
+        receiverContext.setCarrier(new Object());
+        receiverContext.setName("foo");
+
+        handler.onStart(receiverContext);
+        handler.onEvent(event, receiverContext);
+        handler.onStop(receiverContext);
+
+        MutableSpan data = takeOnlySpan();
+        then(data.annotations()).hasSize(1);
+        then(data.annotations().stream().findFirst()).isPresent().get().extracting(Map.Entry::getValue).isSameAs("bar");
+    }
+
+    private MutableSpan takeOnlySpan() {
+        List<MutableSpan> spans = testSpanHandler.spans();
+        then(spans).hasSize(1);
+        MutableSpan mutableSpan = spans.get(0);
+        return mutableSpan;
+    }
+
+}

micrometer-tracing-bridges/micrometer-tracing-bridge-brave/src/test/java/io/micrometer/tracing/brave/handler/PropagatingSenderTracingObservationHandlerBraveTests.java

@@ -20,6 +20,7 @@
 import brave.handler.MutableSpan;
 import brave.test.TestSpanHandler;
 import io.micrometer.observation.Observation;
+import io.micrometer.observation.Observation.Event;
 import io.micrometer.observation.ObservationHandler;
 import io.micrometer.observation.tck.TestObservationRegistry;
 import io.micrometer.observation.transport.SenderContext;
@@ -33,6 +34,7 @@
 import org.junit.jupiter.api.Test;
 
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 import static org.assertj.core.api.BDDAssertions.then;
@@ -47,8 +49,8 @@ class PropagatingSenderTracingObservationHandlerBraveTests {
     Tracer tracer = new BraveTracer(tracing.tracer(), new BraveCurrentTraceContext(tracing.currentTraceContext()),
             new BraveBaggageManager());
 
-    PropagatingSenderTracingObservationHandler<?> handler = new PropagatingSenderTracingObservationHandler<>(tracer,
-            new BravePropagator(tracing));
+    PropagatingSenderTracingObservationHandler<? super SenderContext<?>> handler = new PropagatingSenderTracingObservationHandler<>(
+            tracer, new BravePropagator(tracing));
 
     @Test
     void should_be_applicable_for_non_null_context() {
@@ -88,6 +90,23 @@ void should_create_a_child_span_when_parent_was_present() {
         then(childFinishedSpan.getParentId()).isEqualTo(parentFinishedSpan.getSpanId());
     }
 
+    @Test
+    void should_signal_events() {
+        Event event = Event.of("foo", "bar");
+        SenderContext<?> senderContext = new SenderContext<>((carrier, key, value) -> {
+            // no-op
+        });
+        senderContext.setName("foo");
+
+        handler.onStart(senderContext);
+        handler.onEvent(event, senderContext);
+        handler.onStop(senderContext);
+
+        MutableSpan data = takeOnlySpan();
+        then(data.annotations()).hasSize(1);
+        then(data.annotations().stream().findFirst()).isPresent().get().extracting(Map.Entry::getValue).isSameAs("bar");
+    }
+
     private MutableSpan takeOnlySpan() {
         List<MutableSpan> spans = testSpanHandler.spans();
         then(spans).hasSize(1);

micrometer-tracing-bridges/micrometer-tracing-bridge-otel/src/test/java/io/micrometer/tracing/otel/handler/PropagatingReceiverTracingObservationHandlerOtelTests.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2013-2021 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.micrometer.tracing.otel.handler;
+
+import io.micrometer.observation.Observation.Event;
+import io.micrometer.observation.transport.ReceiverContext;
+import io.micrometer.tracing.Tracer;
+import io.micrometer.tracing.handler.PropagatingReceiverTracingObservationHandler;
+import io.micrometer.tracing.otel.bridge.*;
+import io.opentelemetry.context.propagation.ContextPropagators;
+import io.opentelemetry.extension.trace.propagation.B3Propagator;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
+import io.opentelemetry.sdk.trace.SdkTracerProvider;
+import io.opentelemetry.sdk.trace.data.EventData;
+import io.opentelemetry.sdk.trace.data.SpanData;
+import io.opentelemetry.sdk.trace.export.SimpleSpanProcessor;
+import org.junit.jupiter.api.Test;
+
+import java.util.Collections;
+import java.util.Queue;
+
+import static org.assertj.core.api.BDDAssertions.then;
+
+class PropagatingReceiverTracingObservationHandlerOtelTests {
+
+    ArrayListSpanProcessor testSpanProcessor = new ArrayListSpanProcessor();
+
+    SdkTracerProvider sdkTracerProvider = SdkTracerProvider.builder()
+            .setSampler(io.opentelemetry.sdk.trace.samplers.Sampler.alwaysOn())
+            .addSpanProcessor(SimpleSpanProcessor.create(testSpanProcessor)).build();
+
+    OpenTelemetrySdk openTelemetrySdk = OpenTelemetrySdk.builder().setTracerProvider(sdkTracerProvider)
+            .setPropagators(ContextPropagators.create(B3Propagator.injectingSingleHeader())).build();
+
+    io.opentelemetry.api.trace.Tracer otelTracer = openTelemetrySdk.getTracer("io.micrometer.micrometer-tracing");
+
+    Tracer tracer = new OtelTracer(otelTracer, new OtelCurrentTraceContext(), event -> {
+    }, new OtelBaggageManager(new OtelCurrentTraceContext(), Collections.emptyList(), Collections.emptyList()));
+
+    PropagatingReceiverTracingObservationHandler<ReceiverContext<?>> handler = new PropagatingReceiverTracingObservationHandler<>(
+            tracer, new OtelPropagator(ContextPropagators.noop(), otelTracer));
+
+    @Test
+    void should_signal_events() {
+        Event event = Event.of("foo", "bar");
+        ReceiverContext<Object> receiverContext = new ReceiverContext<>((carrier, key) -> "val");
+        receiverContext.setCarrier(new Object());
+        receiverContext.setName("foo");
+
+        handler.onStart(receiverContext);
+        handler.onEvent(event, receiverContext);
+        handler.onStop(receiverContext);
+
+        SpanData data = takeOnlySpan();
+        then(data.getEvents()).hasSize(1).element(0).extracting(EventData::getName).isEqualTo("bar");
+    }
+
+    private SpanData takeOnlySpan() {
+        Queue<SpanData> spans = testSpanProcessor.spans();
+        then(spans).hasSize(1);
+        return testSpanProcessor.takeLocalSpan();
+    }
+
+}

micrometer-tracing-bridges/micrometer-tracing-bridge-otel/src/test/java/io/micrometer/tracing/otel/handler/PropagatingSenderTracingObservationHandlerOtelTests.java

@@ -17,6 +17,7 @@
 package io.micrometer.tracing.otel.handler;
 
 import io.micrometer.observation.Observation;
+import io.micrometer.observation.Observation.Event;
 import io.micrometer.observation.ObservationHandler;
 import io.micrometer.observation.tck.TestObservationRegistry;
 import io.micrometer.observation.transport.SenderContext;
@@ -31,11 +32,14 @@
 import io.opentelemetry.extension.trace.propagation.B3Propagator;
 import io.opentelemetry.sdk.OpenTelemetrySdk;
 import io.opentelemetry.sdk.trace.SdkTracerProvider;
+import io.opentelemetry.sdk.trace.data.EventData;
+import io.opentelemetry.sdk.trace.data.SpanData;
 import io.opentelemetry.sdk.trace.export.SimpleSpanProcessor;
 import org.junit.jupiter.api.Test;
 
 import java.util.Collections;
 import java.util.List;
+import java.util.Queue;
 import java.util.stream.Collectors;
 
 import static org.assertj.core.api.BDDAssertions.then;
@@ -57,8 +61,8 @@ class PropagatingSenderTracingObservationHandlerOtelTests {
     Tracer tracer = new OtelTracer(otelTracer, new OtelCurrentTraceContext(), event -> {
     }, new OtelBaggageManager(new OtelCurrentTraceContext(), Collections.emptyList(), Collections.emptyList()));
 
-    PropagatingSenderTracingObservationHandler<?> handler = new PropagatingSenderTracingObservationHandler<>(tracer,
-            new OtelPropagator(ContextPropagators.noop(), otelTracer));
+    PropagatingSenderTracingObservationHandler<? super SenderContext<?>> handler = new PropagatingSenderTracingObservationHandler<>(
+            tracer, new OtelPropagator(ContextPropagators.noop(), otelTracer));
 
     @Test
     void should_be_applicable_for_non_null_context() {
@@ -98,4 +102,26 @@ void should_create_a_child_span_when_parent_was_present() {
         then(childFinishedSpan.getParentId()).isEqualTo(parentFinishedSpan.getSpanId());
     }
 
+    @Test
+    void should_signal_events() {
+        Event event = Event.of("foo", "bar");
+        SenderContext<?> senderContext = new SenderContext<>((carrier, key, value) -> {
+            // no-op
+        });
+        senderContext.setName("foo");
+
+        handler.onStart(senderContext);
+        handler.onEvent(event, senderContext);
+        handler.onStop(senderContext);
+
+        SpanData data = takeOnlySpan();
+        then(data.getEvents()).hasSize(1).element(0).extracting(EventData::getName).isEqualTo("bar");
+    }
+
+    private SpanData takeOnlySpan() {
+        Queue<SpanData> spans = testSpanProcessor.spans();
+        then(spans).hasSize(1);
+        return testSpanProcessor.takeLocalSpan();
+    }
+
 }

micrometer-tracing/src/main/java/io/micrometer/tracing/handler/PropagatingReceiverTracingObservationHandler.java

@@ -17,6 +17,7 @@
 package io.micrometer.tracing.handler;
 
 import io.micrometer.observation.Observation;
+import io.micrometer.observation.Observation.Event;
 import io.micrometer.observation.transport.ReceiverContext;
 import io.micrometer.tracing.Span;
 import io.micrometer.tracing.Tracer;
@@ -66,6 +67,11 @@ public Span.Builder customizeExtractedSpan(T context, Span.Builder builder) {
         return builder;
     }
 
+    @Override
+    public void onEvent(Event event, T context) {
+        getTracingContext(context).getSpan().event(event.getContextualName());
+    }
+
     @Override
     public void onError(T context) {
         context.getError().ifPresent(throwable -> getRequiredSpan(context).error(throwable));

micrometer-tracing/src/main/java/io/micrometer/tracing/handler/PropagatingSenderTracingObservationHandler.java

@@ -17,6 +17,7 @@
 package io.micrometer.tracing.handler;
 
 import io.micrometer.observation.Observation;
+import io.micrometer.observation.Observation.Event;
 import io.micrometer.observation.transport.SenderContext;
 import io.micrometer.tracing.Span;
 import io.micrometer.tracing.Tracer;
@@ -77,6 +78,11 @@ public void onError(T context) {
         context.getError().ifPresent(throwable -> getRequiredSpan(context).error(throwable));
     }
 
+    @Override
+    public void onEvent(Event event, T context) {
+        getTracingContext(context).getSpan().event(event.getContextualName());
+    }
+
     @Override
     public void onStop(T context) {
         Span span = getRequiredSpan(context);