Span parent ids not being allocated correctly

[peternewnham]

I'm using the module (which is great btw), however I've noticed that parent ids are not being allocated correctly to nested spans.

With a simple app that imports the default OpenTelemetryModule module and has a controller that calls some service methods, the spans that are generated all have a parentId of the root span instead of their actual parents:

HTTP (id: 1, parentId: undefined)
-> Controller (id: 2, parentId: 1)
  -> Service1 (id: 3, parentId: 1)    - parentId should be 2
    -> Service3 (id: 5, parentId: 1)  - parentId should be 3
  -> Service2 (id: 4, parentId: 1)    - parentId should be 2

This means that spans aren't being grouped correctly.

I've applied a patch to my local version which corrects this behaviour and am happy to submit a PR here as well but wanted to get an opinion on it first in case there's something fundamentally wrong with what i'm doing that i'm not aware of 😄

class BaseTraceInjector {
  protected wrap() {
    const method = {
      [prototype.name]: function (...args: any[]) {
        const tracer = trace.getTracer('default');

        // this is the offender - trace.getSpan(context.active()) always returns the top level 'default' span
        //const currentSpan = trace.getSpan(context.active()) ?? tracer.startSpan('default');

        // instead create the new span with the traceName outside of context.with and use that to create the context
        // all nested spans will now be allocated this span as their parent
        const span = tracer.startSpan(traceName);

        return context.with(
          trace.setSpan(context.active(), span),
          () => {
            // no need to create the span inside here now
            //const span = tracer.startSpan(traceName);

           // everything else stays the same
  }
}

[MetinSeylan]

Hi, @peternewnham thank you for your kind words. Your point is correct I tested it in my local. Can you open pr?

[MetinSeylan]

thank you @peternewnham. released https://github.com/MetinSeylan/Nestjs-OpenTelemetry/releases/tag/v2.0.7