feat: support flat config with FlatESLint

[KTibow]

Versions:

• prettier-eslint version: latest (using prettier-eslint-cli)
• node version: v21.1.0
• pnpm version: 8.7.4

Have you followed the debugging tips?
Yes

Relevant code

<h1 class="var-crsv mb-6 mt-12 text-center text-5xl">more pages</h1>

What I did:
Ran pnpm dlx prettier-eslint-cli src/routes/more/+page.svelte --write --log-level debug

What happened:
It did not sort the unocss rules, even though my ESlint config (flat) has unocss enabled, and eslint --fix src/routes/more/+page.svelte works fine

Logs:

prettier-eslint [DEBUG]: getting eslint config for file at "/home/kendell/Documents/Projects/SchoolHub/src/routes/more/+page.svelte"
prettier-eslint [DEBUG]: Unable to find config
prettier-eslint [DEBUG]: turning off unfixable rules
prettier-eslint [DEBUG]: The tabWidth rule is not configured, let prettier decide
prettier-eslint [DEBUG]: The singleQuote rule is not configured, let prettier decide
prettier-eslint [DEBUG]: The trailingComma rule is not configured, let prettier decide
prettier-eslint [DEBUG]: The bracketSpacing rule is not configured, let prettier decide
prettier-eslint [DEBUG]: The semi rule is not configured, let prettier decide
prettier-eslint [DEBUG]: The useTabs rule is not configured, let prettier decide
prettier-eslint [DEBUG]: The bracketSameLine rule is not configured, let prettier decide
prettier-eslint [DEBUG]: The arrowParens rule is not configured, let prettier decide
prettier-eslint [DEBUG]: inferred options: Object {
  "eslintConfig": Object {
    "fix": true,
    "globals": Object {},
    "rules": Object {
      "accessor-pairs": Array [
        "off",
      ],
      "array-callback-return": Array [
        "off",
      ],
      "block-scoped-var": Array [
        "off",
      ],
      "callback-return": Array [
        "off",
      ],
      "camelcase": Array [
        "off",
      ],
      "class-methods-use-this": Array [
        "off",
      ],
      "complexity": Array [
        "off",
      ],
      "consistent-return": Array [
        "off",
      ],
      "consistent-this": Array [
        "off",
      ],
      "constructor-super": Array [
        "off",
      ],
      "default-case": Array [
        "off",
      ],
      "default-case-last": Array [
        "off",
      ],
      "default-param-last": Array [
        "off",
      ],
      "for-direction": Array [
        "off",
      ],
      "func-name-matching": Array [
        "off",
      ],
      "func-names": Array [
        "off",
      ],
      "func-style": Array [
        "off",
      ],
      "getter-return": Array [
        "off",
      ],
      "global-require": Array [
        "off",
      ],
      "grouped-accessor-pairs": Array [
        "off",
      ],
      "guard-for-in": Array [
        "off",
      ],
      "handle-callback-err": Array [
        "off",
      ],
      "id-blacklist": Array [
        "off",
      ],
      "id-denylist": Array [
        "off",
      ],
      "id-length": Array [
        "off",
      ],
      "id-match": Array [
        "off",
      ],
      "init-declarations": Array [
        "off",
      ],
      "line-comment-position": Array [
        "off",
      ],
      "max-classes-per-file": Array [
        "off",
      ],
      "max-depth": Array [
        "off",
      ],
      "max-len": Array [
        "off",
      ],
      "max-lines": Array [
        "off",
      ],
      "max-lines-per-function": Array [
        "off",
      ],
      "max-nested-callbacks": Array [
        "off",
      ],
      "max-params": Array [
        "off",
      ],
      "max-statements": Array [
        "off",
      ],
      "max-statements-per-line": Array [
        "off",
      ],
      "new-cap": Array [
        "off",
      ],
      "no-alert": Array [
        "off",
      ],
      "no-array-constructor": Array [
        "off",
      ],
      "no-async-promise-executor": Array [
        "off",
      ],
      "no-await-in-loop": Array [
        "off",
      ],
      "no-bitwise": Array [
        "off",
      ],
      "no-buffer-constructor": Array [
        "off",
      ],
      "no-caller": Array [
        "off",
      ],
      "no-case-declarations": Array [
        "off",
      ],
      "no-catch-shadow": Array [
        "off",
      ],
      "no-class-assign": Array [
        "off",
      ],
      "no-compare-neg-zero": Array [
        "off",
      ],
      "no-cond-assign": Array [
        "off",
      ],
      "no-console": Array [
        "off",
      ],
      "no-const-assign": Array [
        "off",
      ],
      "no-constant-binary-expression": Array [
        "off",
      ],
      "no-constant-condition": Array [
        "off",
      ],
      "no-constructor-return": Array [
        "off",
      ],
      "no-continue": Array [
        "off",
      ],
      "no-control-regex": Array [
        "off",
      ],
      "no-debugger": Array [
        "off",
      ],
      "no-delete-var": Array [
        "off",
      ],
      "no-dupe-args": Array [
        "off",
      ],
      "no-dupe-class-members": Array [
        "off",
      ],
      "no-dupe-else-if": Array [
        "off",
      ],
      "no-dupe-keys": Array [
        "off",
      ],
      "no-duplicate-case": Array [
        "off",
      ],
      "no-duplicate-imports": Array [
        "off",
      ],
      "no-empty": Array [
        "off",
      ],
      "no-empty-character-class": Array [
        "off",
      ],
      "no-empty-function": Array [
        "off",
      ],
      "no-empty-pattern": Array [
        "off",
      ],
      "no-empty-static-block": Array [
        "off",
      ],
      "no-eq-null": Array [
        "off",
      ],
      "no-eval": Array [
        "off",
      ],
      "no-ex-assign": Array [
        "off",
      ],
      "no-extend-native": Array [
        "off",
      ],
      "no-fallthrough": Array [
        "off",
      ],
      "no-func-assign": Array [
        "off",
      ],
      "no-global-assign": Array [
        "off",
      ],
      "no-implicit-globals": Array [
        "off",
      ],
      "no-implied-eval": Array [
        "off",
      ],
      "no-import-assign": Array [
        "off",
      ],
      "no-inline-comments": Array [
        "off",
      ],
      "no-inner-declarations": Array [
        "off",
      ],
      "no-invalid-regexp": Array [
        "off",
      ],
      "no-invalid-this": Array [
        "off",
      ],
      "no-irregular-whitespace": Array [
        "off",
      ],
      "no-iterator": Array [
        "off",
      ],
      "no-label-var": Array [
        "off",
      ],
      "no-labels": Array [
        "off",
      ],
      "no-lone-blocks": Array [
        "off",
      ],
      "no-loop-func": Array [
        "off",
      ],
      "no-loss-of-precision": Array [
        "off",
      ],
      "no-magic-numbers": Array [
        "off",
      ],
      "no-misleading-character-class": Array [
        "off",
      ],
      "no-mixed-operators": Array [
        "off",
      ],
      "no-mixed-requires": Array [
        "off",
      ],
      "no-mixed-spaces-and-tabs": Array [
        "off",
      ],
      "no-multi-assign": Array [
        "off",
      ],
      "no-multi-str": Array [
        "off",
      ],
      "no-native-reassign": Array [
        "off",
      ],
      "no-negated-condition": Array [
        "off",
      ],
      "no-negated-in-lhs": Array [
        "off",
      ],
      "no-nested-ternary": Array [
        "off",
      ],
      "no-new": Array [
        "off",
      ],
      "no-new-func": Array [
        "off",
      ],
      "no-new-native-nonconstructor": Array [
        "off",
      ],
      "no-new-object": Array [
        "off",
      ],
      "no-new-require": Array [
        "off",
      ],
      "no-new-symbol": Array [
        "off",
      ],
      "no-new-wrappers": Array [
        "off",
      ],
      "no-nonoctal-decimal-escape": Array [
        "off",
      ],
      "no-obj-calls": Array [
        "off",
      ],
      "no-object-constructor": Array [
        "off",
      ],
      "no-octal": Array [
        "off",
      ],
      "no-octal-escape": Array [
        "off",
      ],
      "no-param-reassign": Array [
        "off",
      ],
      "no-path-concat": Array [
        "off",
      ],
      "no-plusplus": Array [
        "off",
      ],
      "no-process-env": Array [
        "off",
      ],
      "no-process-exit": Array [
        "off",
      ],
      "no-promise-executor-return": Array [
        "off",
      ],
      "no-proto": Array [
        "off",
      ],
      "no-prototype-builtins": Array [
        "off",
      ],
      "no-redeclare": Array [
        "off",
      ],
      "no-restricted-exports": Array [
        "off",
      ],
      "no-restricted-globals": Array [
        "off",
      ],
      "no-restricted-imports": Array [
        "off",
      ],
      "no-restricted-modules": Array [
        "off",
      ],
      "no-restricted-properties": Array [
        "off",
      ],
      "no-restricted-syntax": Array [
        "off",
      ],
      "no-return-assign": Array [
        "off",
      ],
      "no-return-await": Array [
        "off",
      ],
      "no-script-url": Array [
        "off",
      ],
      "no-self-assign": Array [
        "off",
      ],
      "no-self-compare": Array [
        "off",
      ],
      "no-sequences": Array [
        "off",
      ],
      "no-setter-return": Array [
        "off",
      ],
      "no-shadow": Array [
        "off",
      ],
      "no-shadow-restricted-names": Array [
        "off",
      ],
      "no-sparse-arrays": Array [
        "off",
      ],
      "no-sync": Array [
        "off",
      ],
      "no-tabs": Array [
        "off",
      ],
      "no-template-curly-in-string": Array [
        "off",
      ],
      "no-ternary": Array [
        "off",
      ],
      "no-this-before-super": Array [
        "off",
      ],
      "no-throw-literal": Array [
        "off",
      ],
      "no-undef": Array [
        "off",
      ],
      "no-undefined": Array [
        "off",
      ],
      "no-underscore-dangle": Array [
        "off",
      ],
      "no-unexpected-multiline": Array [
        "off",
      ],
      "no-unmodified-loop-condition": Array [
        "off",
      ],
      "no-unreachable": Array [
        "off",
      ],
      "no-unreachable-loop": Array [
        "off",
      ],
      "no-unsafe-finally": Array [
        "off",
      ],
      "no-unsafe-negation": Array [
        "off",
      ],
      "no-unsafe-optional-chaining": Array [
        "off",
      ],
      "no-unused-expressions": Array [
        "off",
      ],
      "no-unused-private-class-members": Array [
        "off",
      ],
      "no-unused-vars": Array [
        "off",
      ],
      "no-use-before-define": Array [
        "off",
      ],
      "no-useless-backreference": Array [
        "off",
      ],
      "no-useless-call": Array [
        "off",
      ],
      "no-useless-catch": Array [
        "off",
      ],
      "no-useless-concat": Array [
        "off",
      ],
      "no-useless-constructor": Array [
        "off",
      ],
      "no-useless-escape": Array [
        "off",
      ],
      "no-void": Array [
        "off",
      ],
      "no-warning-comments": Array [
        "off",
      ],
      "no-with": Array [
        "off",
      ],
      "prefer-named-capture-group": Array [
        "off",
      ],
      "prefer-promise-reject-errors": Array [
        "off",
      ],
      "prefer-reflect": Array [
        "off",
      ],
      "prefer-regex-literals": Array [
        "off",
      ],
      "prefer-rest-params": Array [
        "off",
      ],
      "prefer-spread": Array [
        "off",
      ],
      "radix": Array [
        "off",
      ],
      "require-atomic-updates": Array [
        "off",
      ],
      "require-await": Array [
        "off",
      ],
      "require-jsdoc": Array [
        "off",
      ],
      "require-unicode-regexp": Array [
        "off",
      ],
      "require-yield": Array [
        "off",
      ],
      "sort-keys": Array [
        "off",
      ],
      "symbol-description": Array [
        "off",
      ],
      "use-isnan": Array [
        "off",
      ],
      "valid-typeof": Array [
        "off",
      ],
      "vars-on-top": Array [
        "off",
      ],
    },
    "useEslintrc": false,
  },
  "eslintPath": "/home/kendell/Documents/Projects/SchoolHub/node_modules/.pnpm/eslint@8.55.0/node_modules/eslint/lib/api.js",
  "filePath": "/home/kendell/Documents/Projects/SchoolHub/src/routes/more/+page.svelte",
  "logLevel": "debug",
  "prettierLast": false,
  "prettierOptions": Object {
    "arrowParens": undefined,
    "bracketSpacing": undefined,
    "filepath": "/home/kendell/Documents/Projects/SchoolHub/src/routes/more/+page.svelte",
    "insertPragma": undefined,
    "plugins": Array [
      "prettier-plugin-svelte",
    ],
    "printWidth": 100,
    "proseWrap": undefined,
    "requirePragma": undefined,
    "semi": undefined,
    "singleQuote": undefined,
    "useTabs": undefined,
  },
  "prettierPath": "/home/kendell/Documents/Projects/SchoolHub/node_modules/.pnpm/prettier@3.1.1/node_modules/prettier/index.cjs",
  "text": "
<h1 class=\"var-crsv mb-6 mt-12 text-center text-5xl\">more pages</h1>
",
}
prettier-eslint [DEBUG]: calling prettier on text

Suggested solution:
Fix the bug? Not sure what to say

[JounQin]

Online reproduction required.

[KTibow]

Minimal repro: https://github.com/KTibow/prettier-eslint-repro

[JounQin]

Related codes:

prettier-eslint/src/utils.js

Line 407 in d4d55fd

return new ESLint(eslintOptions);

We need to construct new FlatESLint for flat config instead.

PR welcome if you're interested, otherwise I may help to add this feature later when I'm free.

[github-actions]

Stale issue

[KTibow]

Nope

[github-actions]

Stale issue

[KTibow]

Nope