feat: Instrument calls to libraries

[zermelo-wisen]

Fixes#83

[dividedmind]

I think you're on the right track. Couple of comments:

• Will this work for ESM? I'm worried the whole approach will need to be different. Unless we can use the same trick for CJS-loading and hoping the hooked module will be cached across the two loaders...
• The Error approach is a no-go; it will have an unacceptably massive performance hit. Also, it's maybe a bit too complicated; appmap-ruby skips tracing if current_package.shallow? && last_package == current_package (where package is just an appmap.ymlpackage: entry), which is extremely simple and works well in practice. This also allows shallow mode to work for user (eg. path:) packages, a feature occasionally useful.

[dividedmind]

Please try to use import type when applicable to make it clear when code is being imported vs. just types.

[dividedmind]

• Will this work for ESM? I'm worried the whole approach will need to be different. Unless we can use the same trick for CJS-loading and hoping the hooked module will be cached across the two loaders...

BTW, I think if ESM support is going to be non-trivial it's ok to just do this for CJS for now and open a separate issue to add ESM support later.

[zermelo-wisen]

• Will this work for ESM? I'm worried the whole approach will need to be different. Unless we can use the same trick for CJS-loading and hoping the hooked module will be cached across the two loaders...

BTW, I think if ESM support is going to be non-trivial it's ok to just do this for CJS for now and open a separate issue to add ESM support later.

It was trivial for built-ins. For third party libs I managed to do it by implementing resolve function in our custom loader.