Remove all deprecated React lifecycle methods

[timroes]

Summary

React will introduce async rendering and deprecate some lifecycle methods in the upcoming 16.x versions, since they are replaced with new lifecycle methods. Since these lifecycle methods, will be removed with React 17.0, we'll need to remove all of the deprecated lifecycle methods, before we update to React 17.0 in the future. This is the meta ticket, to remind us to remove all of those lifecycle methods.

The following lifecycle methods will be removed in the future:

• componentWillUpdate
• componentWillReceiveProps
• componentWillMount

Most of the use-cases of these lifecycle methods can be solved with some other life-cycle method or one of the two new methods:

• static getDerivedStateFromProps
• getSnapshotBeforeUpdate

More resources

A detailed explanation of the migration with a lot of use-case examples can be found in Facebook's blog post. Since the blog post doesn't have a table of content, here are a list of possible use-cases that used the deprecated lifecycle methods:

• Initializing State
• Fetching external data
• Adding event listeners (or subscriptions)
• Updating state based on Props
• Invoking external callbacks
• Update external data when props change
• Reading DOM properties before an update

Another resource, but not providing any more information than the above blog post, is the React 16.3 release blog post.

To be refactored

All of the following features are currently using componentWillMount and/or componentWillReceiveProps and should thus be refactored before React 17 or replaced completely (like Kibana UI framework).

• Kibana Home
• Kibana UI Framework
• Dashboard Components & Grid
• Index Pattern Wizard / Edit Index Patterns
• TSVB
• Input Control Vis
• Markdown Vis

[w33ble]

16.3.0 was released yesterday: https://github.com/facebook/react/releases/tag/v16.3.0

[w33ble]

There's an open issue in eslint-plugin-react about removing a couple of the recommended rules, see jsx-eslint/eslint-plugin-react#1754. From the author:

"componentWillMount", "componentWillUpdate", "componentWillReceiveProps" will be deprecated life-cycle methods (React 16.3.0, introduced these and deprecation warnings are scheduled to come with 16.4.0), and replacements for those will be accordingly "componentWillMount" => "componentDidMount", "componentWillUpdate"  => "componentDidUpdate" and "componentWillReceiveProps" => with new introduced "getDerivedStateFromProps".

Therefore it's not relevant to have this rule and existing code bases should be migrated soon enough to match new life-cycles.

We may consider removing those rules from eslint-config-kibana as well, unless we find that it's something we want to explicitly add exceptions to in the code as needed.

[kertal]

We're moving to React 16.12, there will be lots of deprecation warnings, after #51145 will be merged. There will be a follow up PR with a codemod, but that will just rename the functions to remove the warnings. So we should refactor code to remove those deprecated functions