Expose plugin contracts to Legacy platform

[mshustov]

Summary

Expose plugin contracts to Legacy platform and unify LegacyService.setup/start interfaces for server and client parts.

Checklist

Use strikethroughs to remove checklist items you don't feel are applicable to this PR.

• [ ] This was checked for cross-browser compatibility, including a check against IE11
• [ ] Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• [ ] Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios
• [ ] This was checked for keyboard-only and screenreader accessibility

For maintainers

• This was checked for breaking API changes and was labeled appropriately
• This includes a feature addition or change that requires a release note and was labeled appropriately

Dev Docs

If you want to use a New Platform plugin in Legacy Platform you could access them

• on client

import { getNewPlatform } from 'ui/new_platform';
const plugins: Record<string, unknown> = getNewPlatform().setup.plugins

• on server

new kibana.Plugin({
  init(server){
    const plugins: Record<string, unknown> = server.newPlatform.setup.plugins;
  }
})

[elasticmachine]

Pinging @elastic/kibana-platform

[elasticmachine]

💚 Build Succeeded

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

[streamich]

LGTM.

[mistic]

The changes within respect to the operations team LGTM

[joshdover]

I'd prefer this file to exist in src/core/utils rather than litter the top-level public directory of core.

[mshustov]

I can move, np. afair we were going to remove this folder. aren't we?

[mshustov]

as for me I'm fine to keep this folder for such env-agnostic utils

[joshdover]

We discussed real quick and decided we're fine with the src/core/utils directory existing for only very generic vanilla JS utilities similar to what you'd find in lodash or a standard library.

[spalger]

Object.fromEntries(map.entries())?

[mshustov]

I tried. but TS told me this is too fresh syntax 😄

another interesting case for you, TS allows me to use [].flatMap, because:

  // tsconfig.ts
  // Node 8 should support everything output by esnext, we override this
  // in webpack with loader-level compiler options
  "target": "esnext",

but it's not implemented in node v10, they added it in v11.
so our TS setup is a bit misleading

[elasticmachine]

💚 Build Succeeded

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