Expression forks

[streamich]

Summary

Closes #56747

Checklist

Delete any items that are not applicable to this PR.

• Unit or functional tests were updated or added to match the most common scenarios

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• This was checked for breaking API changes and was labeled appropriately

[elasticmachine]

Pinging @elastic/kibana-app-arch (Team:AppArch)

[ppisljar]

code LGTM

[crob611]

Code looks good to me as well.

Trying to think through all of the possible scenarios that could come up. Should we ever allow adding to the main instance, or should that be reserved strictly for expressions plugin itself? Thinking of the scenario where Canvas is using a fork, but another plugin is just adding it's stuff directly to main.

[streamich]

@crob611 the idea here is that, both, Lens and Canvas would use forks. There would be default functions in the global registry provided by expressions plugin but also anyone would be able to add more functions to the global registry. Thus, for example, Canvas could add essql function to the global registry so that Lens also has access to it. Though functions registered in the local forks would not be visible to other instances, for example, Lens would register all its lens_* functions in its local registry, thus Canvas will not see those.

That was how I thought about it. But if you have further concerns, say Canvas does not want to make any expression functions available in their autocomplete besides the default ones and the ones explicitly registered by Canvas, we could do that too. We could add some method that returns an instance of ExpressionsService which contains only default functions and does not sync with the global registry. But in that case, I'm a bit concerned that we are losing the ability to easily extend expressions plugin by simply registering functions and types in the global registry.

[kibanamachine]

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• continuous-integration/kibana-ci/pull-request
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History

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