fix(ast-spec): remove more invalid properties

[JoshuaKGoldberg]

BREAKING CHANGE:
Removes properties from ast-spec and therefore typescript-estree

PR Checklist

• Addresses an existing open issue: fixes Remove properties that are used by invalid code #4759
• That issue was marked as accepting prs
• Steps in CONTRIBUTING.md were taken

Overview

Removes the additional properties listed by @bradzacher in #4759.

[typescript-eslint]

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✅ Successfully ran 47 targets

• Node 14 - nx test typescript-estree --coverage=false
• Node 14 - nx test ast-spec --coverage=false
• Node 14 - nx run-many --target=build --parallel --exclude website
• Node 14 - nx test visitor-keys --coverage=false
• Node 14 - nx run-many --target=build --parallel --exclude website
• Node 18 - nx test typescript-estree
• Node 14 - nx test eslint-plugin-tslint --coverage=false
• Node 14 - nx run-many --target=build --parallel --exclude website
• Node 14 - nx test utils --coverage=false
• Node 14 - nx test parser --coverage=false
• Node 14 - nx run-many --target=build --parallel --exclude website
• Node 14 - nx run-many --target=build --parallel --exclude website
• Node 14 - nx test type-utils --coverage=false
• Node 14 - nx run-many --target=build --parallel --exclude website
• Node 14 - nx test scope-manager --coverage=false
• Node 14 - nx test eslint-plugin-internal --coverage=false
• Node 14 - nx run-many --target=build --parallel --exclude website
• Node 14 - nx run-many --target=build --parallel --exclude website
• Node 14 - nx run-many --target=build --parallel --exclude website
• Node 14 - nx test eslint-plugin --coverage=false
• Node 14 - nx run-many --target=build --parallel --exclude website
• Node 18 - nx test type-utils
• Node 18 - nx run-many --target=build --parallel --exclude website
• Node 18 - nx test visitor-keys
• Node 18 - nx run-many --target=build --parallel --exclude website
• nx run-many --target=typecheck --parallel
• Node 18 - nx test utils
• Node 18 - nx run-many --target=build --parallel --exclude website
• Node 18 - nx run-many --target=build --parallel --exclude website
• nx run-many --target=lint --parallel
• Node 18 - nx test ast-spec
• Node 18 - nx run-many --target=build --parallel --exclude website
• nx run-many --target=build --parallel --exclude website
• nx run-many --target=build --parallel --exclude website
• Node 18 - nx test eslint-plugin-internal
• Node 18 - nx run-many --target=build --parallel --exclude website
• nx run-many --target=build --parallel --exclude website
• nx run-many --target=build --parallel --exclude website
• Node 18 - nx test parser
• Node 18 - nx test eslint-plugin-tslint
• Node 18 - nx test eslint-plugin
• Node 18 - nx run-many --target=build --parallel --exclude website
• Node 18 - nx run-many --target=build --parallel --exclude website
• Node 18 - nx test scope-manager
• Node 18 - nx run-many --target=build --parallel --exclude website
• Node 18 - nx run-many --target=build --parallel --exclude website
• nx run-many --target=build --parallel --exclude website

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[bradzacher]

[bradzacher]

hmm - i wonder if we should throw on this specific case?
prettier currently supports it, but other parsers (babel) throw here.

If we don't throw, I believe prettier will just delete the code silently when it formats.
WDYT?

[fisker]

prettier/prettier#14264

[JoshuaKGoldberg]

@bradzacher @fisker I went ahead and added errors for the other @deprecated node properties in typescript.d.ts (TIL!):

interface PropertySignature {
    /** @deprecated A property signature cannot have an initializer */
    readonly initializer?: Expression | undefined;
}
interface PropertyAssignment {
    /** @deprecated A property assignment cannot have a question token */
    readonly questionToken?: QuestionToken | undefined;
    /** @deprecated A property assignment cannot have an exclamation token */
    readonly exclamationToken?: ExclamationToken | undefined;
}
interface ShorthandPropertyAssignment {
    /** @deprecated A shorthand property assignment cannot have modifiers */
    readonly modifiers?: NodeArray<Modifier> | undefined;
    /** @deprecated A shorthand property assignment cannot have a question token */
    readonly questionToken?: QuestionToken | undefined;
    /** @deprecated A shorthand property assignment cannot have an exclamation token */
    readonly exclamationToken?: ExclamationToken | undefined;
}
interface FunctionTypeNode {
    /** @deprecated A function type cannot have modifiers */
    readonly modifiers?: NodeArray<Modifier> | undefined;
}

d3c054f

Do you think this is reasonable for Prettier too? I'd be interested in sending a PR over if so, I haven't actually contributed to Prettier yet!

[fisker]

Great! Saving us from checking those.

[JoshuaKGoldberg]

@fisker I poked around in Prettier-land and couldn't figure out if there was anything else for me to change there. I'll defer to you. If you end up filing an issue in Prettier I'd love to tackle it. But it's a bit much for me on my own. 😅

[fisker]

The invalid modifier check is here in this file https://github.com/prettier/prettier/blob/next/src/language-js/parse/postprocess/typescript.js

[fisker]

And tests are here https://github.com/prettier/prettier/blob/next/tests/format/misc/errors/typescript/modifiers/jsfmt.spec.js

[bradzacher]

cc @fisker / @sosukesuzuki for the prettier POV.

We're removing bits of the AST that shouldn't be there in our next major. All the things we are removing are bad code that should probably be syntax errors, but aren't for because #just-ts-things.

From prettier's POV - would it be better if:
a) we explicitly throw if they're there so that you don't remove them during formatting (because you can't format!)
b) we don't error and the obviously bad, no-op bits of code just disappear during formatting?
c) we don't error, and you look up the info on the TS-AST if you want to keep it during printing.
d) we error and provide a flag that allows us to not error so you can go route (c).

WDYT?

[fisker]

We already check lot's of errors in our next branch, so we can test those properties, it doesn't really matter.

It will be nice to throw errors here, I choose c).

Anyway, it's always good to have a choice, so if not much trouble d) is best for now (we may still need release Prettier 2.x), but after Prettier v3, we definitely don't want hide syntax errors.

[fisker]

Let's kill them ALL!

[bradzacher]

@JoshuaKGoldberg I think we need to be a little stricter here and explicitly error if we encounter this weird bit of syntax.

The issue with just ignoring it is that it'll potentially have downstream effects on ESLint fixers that act on raw source code and could lead to a fixer introducing a syntax error.

[codecov]

Codecov Report

Merging #6243 (03b54f7) into v6 (3915661) will decrease coverage by 0.06%.
The diff coverage is 18.75%.

Additional details and impacted files

@@            Coverage Diff             @@
##               v6    #6243      +/-   ##
==========================================
- Coverage   87.15%   87.10%   -0.06%     
==========================================
  Files         362      362              
  Lines       12459    12470      +11     
  Branches     3688     3688              
==========================================
+ Hits        10859    10862       +3     
- Misses       1253     1261       +8     
  Partials      347      347              

Flag	Coverage Δ
unittest	87.10% <18.75%> (-0.06%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
packages/visitor-keys/src/visitor-keys.ts	100.00% <ø> (ø)
packages/typescript-estree/src/convert.ts	28.68% <18.75%> (-0.03%)	⬇️