Use export type instead of export to reduce bundle size

[stacey-gammon]

It appears that using export { AType } from '..' increases the bundle size, even though they are only types. Lets see what happens if we convert a bunch of those to export type { AType } from '...' in the data plugin, see if bundle size is reduced by a lot.

[elasticmachine]

Pinging @elastic/kibana-app-services (Team:AppServices)

[ppisljar]

10kb ? less then 1% change, do you think its worth it ?

[flash1293]

Kibana app changes LGTM

[stacey-gammon]

@ppisljar ,

10kb ? less then 1% change, do you think its worth it ?

Yea, it's a small gain, but if we do it everywhere, it could add up. @tylersmalley or @spalger - what do you think? Is using export type a useful recommendation to decrease bundle size, or something we shouldn't bother with because the gains are small?

[spalger]

I really don't think that thinking of a 10kb size change as "less than 1%" is helpful, it's a 10kb change and that's important. Reducing our bundles by 2-3mb is made up of lots of little 10kb changes. I think that one of the reasons this is only 10kb is because it's the first place we're doing this, and I think that if we make it a habit across the team and use export type in as many places as possible then we are likely to see dozens of these types of reductions which should add up. I think it's also important to not just use export type in the public/index.ts type files, but throughout the plugin, which I think is another reason we should try to make it a habit to always use export type if it's a valid option.

[stacey-gammon]

@elasticmachine merge upstream

[kibanamachine]

💚 Build Succeeded

• continuous-integration/kibana-ci/pull-request
• Commit: 72c33a0
• Storybooks Preview
• Documentation Changes

Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
data	572	571	-1

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
data	840.3KB	830.9KB	-9.4KB

History

• 💚 Build #130308 succeeded 388b7c4
• 💔 Build #130302 failed 564e551
• 💔 Build #130221 failed 88b02abb90f08bb7f562ea6cc1b742c19bbde571

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@elasticmachine merge upstream

[ppisljar]

code LGTM

[kibanamachine]

💚 Backport successful

Status	Branch	Result
✅	7.x

This backport PR will be merged automatically after passing CI.