[WIP] Remove deprecated lifecycles

[ElreyB]

Fixes # (issue) #540

Type of Change

Please delete options that are not relevant.

• Remove deprecated componentWillReceiveProps with getDerivedStateFromProps
• Remove deprecated componentWillMount with componentDidMount

How Has This Been Tested? (using unit testing)

Checklist: (Feel free to delete this section upon completion)

• My code follows the style guidelines of this project (I have run yarn prettier-fix && yarn lint)
• New and existing unit tests pass locally with my changes (I have run yarn test)
• I have performed a self-review of my own code
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules

[ebrillhart]

This actually should, ideally, not be a breaking change in the sense that it should not affect the functionality for any users of the library, only how the code is written and runs under the hood!

[ElreyB]

@ebrillhart cool beans. I think I just pick the wrong option for that section.

[kale-stew]

This is looking really great! 🎉 I've left a couple of comments and questions 🙂

[kale-stew]

Could I ask why you opted to move this method outside the component?

[ElreyB]

@kale-stew getDerviedStateFromProps does not have access to the component instance. Since buildSlideReference didn't have any component instances in the method itself, I opted to take it out of the class and use it as a regular method that the class can use.

[parkerziegler]

On first glance this looks good @ElreyB! See my one comment about the componentDidUpdate signature. Once we get that up, I'll pull locally and test.

[parkerziegler]

@ebrillhart @kale-stew I symlinked this locally against one of my Spectacle presentations and it worked as expected. I also ran the demo locally after fresh install and all seemed normal there. I think we are likely good for a merge.

It may be worth noting in the CHANGELOG that users will need to ensure they have React and ReactDOM ^16.3.1 as their local dependency (earliest version with stable getDerivedStateFromProps). Not a huge issue, people should hopefully get that update automatically if they yarn upgrade / npm update or start fresh from the boilerplate, but I can see folks just upgrading their spectacle dep, running yarn / npm i, and not getting the React / ReactDOM update b/c of yarn.lock / package-lock.json.

[ebrillhart]

I will merge this and make a note of dependency stuff in the release notes for next release!