Tracer.extract does not return null when no trace context is found in HTTP headers about jaeger-client-node

[yurishkuro]

sounds like a bug. However, we have a use case to return SpanContext with empty traceID but other fields set which is used for starting debug traces.

[yurishkuro]

Opened opentracing/specification#104

[ThomWright]

We've had a problem which I think is related (had to debug though).

Our code looks like this:

const parentContext = tracer.extract(
  FORMAT_HTTP_HEADERS,
  headers,
)
const spanOptions: opentracing.SpanOptions = {
  startTime: startTime.getTime(),
  tags: {
    // ...
  },
}

// Adding this causes problems
if (parentContext != null) {
  spanOptions.references = [opentracing.followsFrom(parentContext)]
}

// edited comment to add this line
const span = tracer.startSpan(OPERATION_NAME, spanOptions)

We get the following error:

Failed to append spans in reporter: error converting span to Thrift: spanId: missing required field "spanId" with id 4 on SpanRef

We've needed to change it to the following:

if (parentContext != null) {
  if ((parentContext as any)._spanIdStr != null) {
    spanOptions.references = [opentracing.followsFrom(parentContext)]
  }
}

Curiously we don't get the same error with spanOptions.childOf. Should I raise a separate issue for this?

[yurishkuro]

.references are not supposed to be mutated after creating the span.

[ThomWright]

.references are not supposed to be mutated after creating the span.

It isn't mutated after creating the span. See my edited comment above. The spanOptions are mutated before creating the span.

[yurishkuro]

@ThomWright it's odd, looks like a bug.