Merge cd09e80520 into affc1a235c

sdk/trace/tracetest/example_test.go

@@ -0,0 +1,60 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package tracetest_test
+
+import (
+	"context"
+	"fmt"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	sdktrace "go.opentelemetry.io/otel/sdk/trace"
+	"go.opentelemetry.io/otel/sdk/trace/tracetest"
+)
+
+// simulateWorkflow starts a “workflow” span and a nested “step-1” span.
+func simulateWorkflow(ctx context.Context) {
+	tracer := otel.Tracer("example/workflow")
+
+	// Parent span “workflow”
+	ctx, workflowSpan := tracer.Start(ctx, "workflow")
+	defer workflowSpan.End()
+	workflowSpan.SetAttributes(attribute.String("workflow.phase", "start"))
+
+	// Child span “step-1”
+	_, stepSpan := tracer.Start(ctx, "step-1")
+	defer stepSpan.End()
+	stepSpan.SetAttributes(attribute.Int("step.order", 1))
+	stepSpan.AddEvent("Step 1 processing started")
+}
+
+// Example_simulateWorkflow is a runnable example.
+// The // Output: comment makes it an executable doc test [2].
+func Example_simulateWorkflow() {
+	ctx := context.Background()
+
+	// In-memory span recorder.
+	recorder := tracetest.NewSpanRecorder()
+	tp := sdktrace.NewTracerProvider(
+		sdktrace.WithSpanProcessor(recorder),
+	)
+	defer tp.Shutdown(ctx)
+
+	// Swap in the test TracerProvider and restore afterwards.
+	orig := otel.GetTracerProvider()
+	otel.SetTracerProvider(tp)
+	defer otel.SetTracerProvider(orig)
+
+	// Run the workflow.
+	simulateWorkflow(ctx)
+
+	// Print span names in the order they ended.
+	for _, s := range recorder.Ended() {
+		fmt.Println(s.Name())
+	}
+
+	// Output:
+	// step-1
+	// workflow
+}