fix: missing global in browser environments

[legendecas]

Which problem is this PR solving?

• Fixes Global is not defined in Angular App #1066

Short description of the changes

• Add fallbacks for global accessing.

[legendecas]

It turns out global shimming can not be turned off for assert depending on it...

[jufab]

I try this fix in my angular app and it works. 👍

[obecny]

I think we should define global per platform and then use it here.
See example how it is done for example here
https://github.com/open-telemetry/opentelemetry-js/tree/b1255217a6f491756335fcb0945f4c8f205e0200/packages/opentelemetry-core/src/platform
You will need to define also a browser section in package.json.

[legendecas]

Yes, but this case is not identical to that one. Ideally, globalThis is preferred for its cross-platform design. However, globalThis only available after Node.js v12 and very new versions of browsers.

For those platform-dependent setups, I do believe they should go into this pattern. But for the global thing, I believe this is ok-ish (or globalThis would be referenced both in their platform/node/global.ts and platform/browser/global.ts).

[obecny]

You have already added a window which doesn't exist in node so this is wrong approach anyway and for such purposes the platform has been done.

[obecny]

and IE still doesn't support globalThis

[dyladan]

As the person who caused this bug in the first place, think I'll defer to @obecny's web browser expertise in this regard. Generally, I don't think we should take advantage of features which are very new and only work on a small subset of very up-to-date installations.

[codecov-commenter]

Codecov Report

Merging #1067 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #1067   +/-   ##
=======================================
  Coverage   94.97%   94.98%           
=======================================
  Files         235      238    +3     
  Lines        9081     9085    +4     
  Branches      821      822    +1     
=======================================
+ Hits         8625     8629    +4     
  Misses        456      456           

Impacted Files	Coverage Δ
packages/opentelemetry-api/src/api/global-utils.ts	100.00% <100.00%> (ø)
packages/opentelemetry-api/src/platform/index.ts	100.00% <100.00%> (ø)
.../opentelemetry-api/src/platform/node/globalThis.ts	100.00% <100.00%> (ø)
...kages/opentelemetry-api/src/platform/node/index.ts	100.00% <100.00%> (ø)

[dyladan]

This LGTM but I want to make sure we get feedback from @obecny

[obecny]

lgtm, thank you

[dyladan]

@open-telemetry/javascript-approvers this is high-priority so please take a look. The API is currently broken in all web scenarios.

[mayurkale22]

@dyladan @obecny Just wonder, why this is not captured by the build? Can we do something here to handle this kind of issues in the compile or build time?

[dyladan]

I would have expected the browser tests to catch this. API tests must not be run in browser? I'll look into it.

[legendecas]

As I mentioned above, webpack added shimming for global in testing so we can access global in the testing environment.

I was trying to disable webpack’s global shimming in testing, but the assert shimming is depending on it, it can not be turned off.

[dyladan]

@legendecas please avoid force pushes where possible. It breaks several features of the github UI useful during code reviews.