This PR removes the non-compliant ChildOf and FollowsFrom interfaces
and the Relation type, which were inherited from OpenTracing via the
initial prototype. Instead allow adding a span context to the go
context as a remote span context and use a simple algorithm for
figuring out an actual parent of the new span, which was proposed for
the OpenTelemetry specification.
Also add a way to ignore current span and remote span context in go
context, so we can force the tracer to create a new root span - a span
with a new trace ID.
That required some moderate changes in the opentracing bridge - first
reference with ChildOfRef reference type becomes a local parent, the
rest become links. This also fixes links handling in the meantime. The
downside of the approach proposed here is that we can only set the
remote parent when creating a span through the opentracing API.
Co-authored-by: Joshua MacDonald <jmacd@users.noreply.github.com>
* Add inspectable test tracer
This adds a test Tracer implementation that tracks its active and ended
spans and uses a Span implementation that can be inspected (e.g., to see
what attributes have been set).
* Ensure test tracer can start spans concurrently
* Flip conditional logic to return early
* Remove duplicate test
* Fix file name casing
🤦
* Add comments to testtrace code
* Remove Link and AddLink methods from test Span
* Enable concurrently setting and getting test attrs
* Remove SetAttribute from test tracer
* Fix test
* Fix names post-rebase
