Next.js 15でESLint 9 / Flat Configに移行する

pnpm lint:next                         

> mysite@ lint:next /Users/mh4gf/ghq/github.com/MH4GF/mysite
> next lint

=============

WARNING: You are currently running a version of TypeScript which is not officially supported by @typescript-eslint/typescript-estree.

You may find that it works just fine, or you may not.

SUPPORTED TYPESCRIPT VERSIONS: >=4.7.4 <5.5.0

YOUR TYPESCRIPT VERSION: 5.6.3

Please only submit bug reports when using the officially supported version.

=============
Error while loading rule '@typescript-eslint/await-thenable': You have used a rule which requires parserServices to be generated. You must therefore provide a value for the "parserOptions.project" property for @typescript-eslint/parser.
Note: detected a parser other than @typescript-eslint/parser. Make sure the parser is configured to forward "parserOptions.project" to @typescript-eslint/parser.
Occurred while linting /Users/mh4gf/ghq/github.com/MH4GF/mysite/app/(pages)/[slug]/_features/Content.tsx
 ELIFECYCLE  Command failed with exit code 1.

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const compat = new FlatCompat({
  baseDirectory: __dirname,
  recommendedConfig: js.configs.recommended,
  allConfig: js.configs.all,
});

pnpm lint:next

> mysite@ lint:next /Users/mh4gf/ghq/github.com/MH4GF/mysite
> next lint


./app/_components/ui/command.tsx
28:11  Error: An interface declaring no members is equivalent to its supertype.  @typescript-eslint/no-empty-object-type

./app/_features/command/items/CommandLinkItem.tsx
19:5  Error: Expected an assignment or function call and instead saw an expression.  @typescript-eslint/no-unused-expressions

./app/_features/command/items/SearchGroup.tsx
39:9  Warning: Unused eslint-disable directive (no problems were reported from 'import/no-unresolved').

./app/_features/markdownRenderer/elements/Paragraph.tsx
23:3  Error: Include a description after the "@ts-expect-error" directive to explain why the @ts-expect-error is necessary. The description must be 10 characters or longer.  @typescript-eslint/ban-ts-comment

./app/_features/richLinkCard/__tests__/getOGP.test.ts
1:1  Warning: Unused eslint-disable directive (no problems were reported from 'import/no-unresolved').

./app/_features/viewTransition/isSameOrigin.ts
8:28  Error: Unexpected constant truthiness on the left-hand side of a `||` expression.  no-constant-binary-expression

info  - Need to disable some ESLint rules? Learn more here: https://nextjs.org/docs/basic-features/eslint#disabling-rules
 ELIFECYCLE  Command failed with exit code 1.

pnpm lint:next

> mysite@ lint:next /Users/mh4gf/ghq/github.com/MH4GF/mysite
> next lint

✔ No ESLint warnings or errors