chore: remove tracer apis not part of spec

[Flarna]

This removes getCurrentSpan(), bind() and with() from Tracer because they are not required by spec and context operations are a concern of context not Tracer.

At least in NoopTracer the implementation of them was incorrect because context was not used.

[codecov]

Codecov Report

Merging #1764 (3866df0) into master (16a3316) will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1764      +/-   ##
==========================================
+ Coverage   92.09%   92.13%   +0.04%     
==========================================
  Files         166      166              
  Lines        5591     5571      -20     
  Branches     1198     1197       -1     
==========================================
- Hits         5149     5133      -16     
+ Misses        442      438       -4     

Impacted Files	Coverage Δ
packages/opentelemetry-api/src/trace/NoopTracer.ts	95.45% <ø> (-1.10%)	⬇️
...ackages/opentelemetry-api/src/trace/ProxyTracer.ts	93.75% <ø> (+11.14%)	⬆️
packages/opentelemetry-tracing/src/Tracer.ts	100.00% <ø> (ø)
packages/opentelemetry-api/src/api/global-utils.ts	100.00% <100.00%> (ø)
...ges/opentelemetry-instrumentation-http/src/http.ts	95.49% <100.00%> (ø)
...emetry-instrumentation-xml-http-request/src/xhr.ts	96.79% <100.00%> (+0.01%)	⬆️
packages/opentelemetry-plugin-fetch/src/fetch.ts	96.55% <100.00%> (+0.02%)	⬆️
...s/opentelemetry-plugin-grpc-js/src/client/utils.ts	93.25% <100.00%> (ø)
...-plugin-grpc-js/src/server/clientStreamAndUnary.ts	100.00% <100.00%> (ø)
...telemetry-plugin-grpc-js/src/server/patchServer.ts	88.52% <100.00%> (ø)
... and 4 more

[dyladan]

Looks good.

For those that don't know, the spec removed these methods from the tracer https://github.com/open-telemetry/opentelemetry-specification/blob/master/specification/trace/api.md#tracer and the only method left in spec is startSpan

[vmarchaud]

lgtm, i understand now why we should maybe namespace the context helpers since those methods has been removed

[obecny]

lgtm,
I think we should provide a short guide in readme "how to upgrade" as withSpan function was very popular and was used widely so people might be confused how they should update code correctly. Would be nice to add this example in readme for some time being

context.with(setActiveSpan(context.active(), span) ...

[Flarna]

@obecny Added a section in readme

Most likely it would be in general good to add something like this for all breaking changes.

[dyladan]

The API_BACKWARDS_COMPATIBILITY_VERSION should be bumped as this change is breaking.

[Flarna]

The API_BACKWARDS_COMPATIBILITY_VERSION should be bumped as this change is breaking.

Should we do this on each PR or once per release?

By the way, we forgot to update this in 0.14.0 (incompatible at least because of #1734)

[dyladan]

Should we do this on each PR or once per release?

Once per release should be fine I think

By the way, we forgot to update this in 0.14.0 (incompatible at least because of #1734)

👀 seems you're right. I'm working on making this use the current version and semver semantics at the moment so hopefully this will be automatic in the future.

[dyladan]

Think this is mergeable when conflicts are fixed