Added SpanProcessor OnEnding callback

sdk/trace/src/test/java/io/opentelemetry/sdk/trace/internal/ExtendedSpanProcessorUsageTest.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.trace.internal;
+
+import static io.opentelemetry.sdk.testing.assertj.OpenTelemetryAssertions.assertThat;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.context.Context;
+import io.opentelemetry.sdk.testing.exporter.InMemorySpanExporter;
+import io.opentelemetry.sdk.trace.ReadWriteSpan;
+import io.opentelemetry.sdk.trace.ReadableSpan;
+import io.opentelemetry.sdk.trace.SdkTracerProvider;
+import io.opentelemetry.sdk.trace.export.SimpleSpanProcessor;
+import org.junit.jupiter.api.Test;
+
+/** Demonstrating usage of {@link ExtendedSpanProcessor}. */
+public class ExtendedSpanProcessorUsageTest {
+
+  private static final AttributeKey<String> FOO_KEY = AttributeKey.stringKey("foo");
+  private static final AttributeKey<String> BAR_KEY = AttributeKey.stringKey("bar");
+
+  private static class CopyFooToBarProcessor implements ExtendedSpanProcessor {
+
+    @Override
+    public void onStart(Context parentContext, ReadWriteSpan span) {}
+
+    @Override
+    public boolean isStartRequired() {
+      return false;
+    }
+
+    @Override
+    public void onEnd(ReadableSpan span) {}
+
+    @Override
+    public boolean isEndRequired() {
+      return false;
+    }
+
+    @Override
+    public void onEnding(ReadWriteSpan span) {
+      String val = span.getAttribute(FOO_KEY);
+      span.setAttribute(BAR_KEY, val);
+    }
+
+    @Override
+    public boolean isOnEndingRequired() {
+      return true;
+    }
+  }
+
+  @Test
+  public void testExtendedSpanProcessorUsage() {
+    InMemorySpanExporter exporter = InMemorySpanExporter.create();
+
+    try (SdkTracerProvider tracerProvider =
+        SdkTracerProvider.builder()
+            .addSpanProcessor(SimpleSpanProcessor.create(exporter))
+            .addSpanProcessor(new CopyFooToBarProcessor())
+            .build()) {
+
+      Tracer tracer = tracerProvider.get("dummy-tracer");
+      Span span = tracer.spanBuilder("my-span").startSpan();
+
+      span.setAttribute(FOO_KEY, "Hello!");
+
+      span.end();
+
+      assertThat(exporter.getFinishedSpanItems())
+          .hasSize(1)
+          .first()
+          .satisfies(
+              spanData -> {
+                assertThat(spanData.getAttributes())
+                    .containsEntry(FOO_KEY, "Hello!")
+                    .containsEntry(BAR_KEY, "Hello!");
+              });
+    }
+  }
+}