Bug: [v8.0.0-alpha.10] incorrect error message Parsing error: "parserOptions.programs"

[OlivierZal]

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• I have tried restarting my IDE and the issue persists.
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Issue Description

Bug discussed and confirmed by @JoshuaKGoldberg and @bradzacher.

Config working with typescript-eslint v7.9.0 does not work with v8.0.0-alpha.10, raising:

/Users/<...>/eslint.config.js
  0:0  error  Parsing error: "parserOptions.programs" has been provided for @typescript-eslint/parser.
The file was not found in any of the provided program instance(s): eslint.config.js

although I don't use any home-made program.

Potential culprit: https://github.com/typescript-eslint/typescript-eslint/pull/8834/files

Reproduction Repository Link

https://github.com/OlivierZal/melcloud-api/blob/e118342a2ce16c49e41e145844bc318e344cfe52/eslint.config.js

Repro Steps

1. git clone https://github.com/OlivierZal/melcloud-api
2. git co e118342a2ce16c49e41e145844bc318e344cfe52
3. eslint .
4. npm i typescript-eslint@8.0.0-alpha.10 --force
5. eslint .
6. compare the 2 outputs (see attached screenshots: v7.9.0 vs v8.0.0-alpha)

Versions

package	version
@typescript-eslint/eslint-plugin	8.0.0-alpha.10
TypeScript	5.4.5
ESLint	9.2.0
node	22.1.0

[bradzacher]

Actually I think the error message is wrong but the error itself is correct.

You have type-aware linting turned on:
https://github.com/OlivierZal/melcloud-api/blob/e118342a2ce16c49e41e145844bc318e344cfe52/eslint.config.js#L15

Then you are using ...tsEslint.configs.disableTypeChecked.rules to disable the type-aware rules
https://github.com/OlivierZal/melcloud-api/blob/e118342a2ce16c49e41e145844bc318e344cfe52/eslint.config.js#L244

However this is a misuse of the config because the config has more than just .rules - it also
https://github.com/typescript-eslint/typescript-eslint/blob/main/packages%2Feslint-plugin%2Fsrc%2Fconfigs%2Fdisable-type-checked.ts#L11

So because you're misusing the config - you never disable type-aware parsing for JS files. You've disabled all the rules but the parser is still generating types for JS files. Hence the parser is erroring on a JS file because it's not included in a tsconfig.

Docs on correct use of the config
https://typescript-eslint.io/users/configs#disable-type-checked
Or alternately (as mentioned on discord) using the extends prop provided by our config util:
https://typescript-eslint.io/packages/typescript-eslint#flat-config-extends

---

So yeah - the message is wrong - it should say Parsing error: "parserOptions.projects" has been provided ...
But the error itself is correct.