Support Optional Chaining in Rules

[bradzacher]

Spinning off of #1033

Rules that need to have support added for optional chaining.
This list was based on a simple grep for MemberExpression and CallExpression, I haven't validated anything beyond that. There are probably extra rules that could do with support as well that don't check MemberExpression and CallExpression.

Rules that require a simple one-line change (i.e. adding a selector):

• consistent-type-assertions (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• explicit-function-return-type (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• func-call-spacing (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• no-array-constructor (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• no-floating-promises (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• no-inferrable-types (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• no-misused-promises (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• no-require-imports (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• no-var-requires (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• prefer-for-of (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• prefer-includes (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• prefer-readonly (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• prefer-regexp-exec (feat(eslint-plugin): optional chain support in rules (part 1) #1253)
• prefer-string-starts-ends-with (feat(eslint-plugin): [pref-str-starts/ends-with] optional chain support #1357)
• require-array-sort-compare (feat(eslint-plugin): more optional chain support in rules #1363)
• unbound-method (feat(eslint-plugin): more optional chain support in rules #1363)

Rules that require a larger enhancement to support (i.e. new feature in rule):

• no-unnecessary-condition (feat(eslint-plugin): [no-unnec-cond] check optional chaining #1315)

Extension rules that will be a pain to update (i.e. base extension rewrite):

• indent / indent-new-do-not-use
• no-extra-parens
  • This one will be a huge pain, and I believe it will involve us duplicating the base rule. The logic is relatively complex, so this is a non-trivial task.
• no-unused-vars

Broken rules due to ESLint not supporting the new AST nodes:

• camelcase [camelcase] False positive with optional chaining #1196
• no-restricted-globals [no-restricted-globals] False positive with optional chaining #1090
• no-undef [no-undef] False positive with optional chaining #1116
• no-unused-expressions [no-unused-expressions] False positive with optional chaining #1138
• no-use-before-define [no-use-before-define] False positive with optional chaining #1104

[bradzacher]

This is issue about enhancing rules by adding support for the new AST.

If you have a bug, please search to see if an issue exists already, or file a new issue if it doesn't

[bradzacher]

Looking into it - no-extra-parens is going to require a much bigger change because of the current implementation.

[bradzacher]

We are a community run project, meaning we rely on community support to get things done outside of critical bugfixes or core infrastructure.
So the timeline is "whenever someone feels like they need this done, and gets around to it".

Happy to accept a PR if there's something missing that is important to you.