Enable doc generation for testing module for InMemory*Exporters.

[lalitb]

Fixes #1466
Design discussion issue (if applicable) #

Changes

Enable doc generation for InMemory*Exporter when built with the testing feature. As it should be possible for users to use these exporters for testing purpose.

The screenshot of the doc from this PR:

Please provide a brief description of the changes here.

Merge requirement checklist

• CONTRIBUTING guidelines followed
• Unit tests added/updated (if applicable)
• Appropriate CHANGELOG.md files updated for non-trivial, user-facing changes
• Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

Attention: 18 lines in your changes are missing coverage. Please review.

Comparison is base (d4a6b3e) 63.8% compared to head (fc02a9f) 63.7%.
Report is 1 commits behind head on main.

Files	Patch %	Lines
...ntelemetry-sdk/src/testing/trace/span_exporters.rs	80.8%	18 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #1503     +/-   ##
=======================================
- Coverage   63.8%   63.7%   -0.1%     
=======================================
  Files        144     144             
  Lines      19983   19983             
=======================================
- Hits       12750   12741      -9     
- Misses      7233    7242      +9     

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[hdost]

Looks good for the most part will have to run docs locally to double check.

[lalitb]

Looks good for the most part will have to run docs locally to double check.

Yes agree, have validated locally and shared the screenshot of the generated docs in the PR description.

[cijothomas]

Looks good for the most part will have to run docs locally to double check.

Okay to merge?

[TommyCpp]

testing used to be a collection of helpers that used by other crates in this repo for unit tests. I understand it maybe helpful to open it up so users can test their custom exporters. But I think we should make sure every helper has basic documentation before merging this

[lalitb]

testing used to be a collection of helpers that used by other crates in this repo for unit tests. I understand it maybe helpful to open it up so users can test their custom exporters. But I think we should make sure every helper has basic documentation before merging this

Currently, only the memory exporters are made open for external users, as required by the specs. Apart from that, the testing module has TestSpanExporter and TestMetricReader. I believe it should be possible to replace them in unit-tests with the in-memory exporters as separate PR. So kept their docs hidden. Let me know if there are other thoughts.

[TommyCpp]

Sounds good! Thanks for fixing it