Add tracetest example for testing instrumentation

Signed-off-by: adity1raut <araut7798@gmail.com>

sdk/trace/tracetest/example_test.go

@@ -0,0 +1,44 @@
+package tracetest_test
+
+import (
+	"context"
+	"testing"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/sdk/trace"
+	"go.opentelemetry.io/otel/sdk/trace/tracetest"
+)
+
+func doSomething(ctx context.Context) {
+	tr := otel.Tracer("example.com/test")
+	_, span := tr.Start(ctx, "doSomething")
+	defer span.End()
+	// simulate some logic
+}
+
+func TestDoSomething(t *testing.T) {
+	// Create a SpanRecorder
+	sr := tracetest.NewSpanRecorder()
+
+	// Create a TracerProvider and register the recorder
+	tp := trace.NewTracerProvider()
+	tp.RegisterSpanProcessor(sr)
+
+	// Set the provider globally
+	otel.SetTracerProvider(tp)
+
+	// Run the function
+	ctx := context.Background()
+	doSomething(ctx)
+
+	// Get spans recorded
+	spans := sr.Ended()
+
+	if len(spans) != 1 {
+		t.Fatalf("Expected 1 span, got %d", len(spans))
+	}
+
+	if spans[0].Name() != "doSomething" {
+		t.Errorf("Expected span name 'doSomething', got %s", spans[0].Name())
+	}
+}