@flizpay-de/eslint/base.js

Shared ESLint flat-config for FlizPay projects

import { FlatCompat } from "@eslint/eslintrc";
import { dirname } from "node:path";
import { fileURLToPath } from "node:url";

import tsPlugin from "@typescript-eslint/eslint-plugin";
import tsParser from "@typescript-eslint/parser";

const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
const compat = new FlatCompat({ baseDirectory: __dirname });

// Base config and rules
export default [
  {
    ignores: [
      "/*", // ignore every top-level entry
      "!/src/**", // …except anything that lives in /src
    ],
  },
  ...compat.config({
    plugins: ["sonarjs", "import", "promise", "security"],
    rules: {
      /* ------------- Core JS ------------- */

      // Disallow use of console.* except console.error
      "no-console": ["error", { allow: ["error"] }],

      /* ------------- API design rules ------------- */

      // Limit a function to at most 2 positional parameters
      "max-params": ["error", 2],

      /* ------------- Maintainability thresholds ------------- */

      // Discourage legacy enums in favor of union types
      "no-restricted-syntax": [
        "error",
        {
          selector: "TSEnumDeclaration",
          message: "Prefer union types over enums",
        },
      ],

      /* ------------- SonarJS / Security / Promise ------------- */

      // Reduce copy‑paste by warning on duplicate string literals
      "sonarjs/no-duplicate-string": "warn",

      // Ensure promises either return a value or explicitly void
      "promise/always-return": "error",

      /* ------------- Import hygiene & sorting ------------- */

      // Prevent missing, extraneous or duplicate dependencies
      "import/no-extraneous-dependencies": ["error", { devDependencies: true }],
    },
  }),
  {
    /* ------------- Core TS rules ------------- */
    files: ["**/*.ts", "**/*.tsx"],
    languageOptions: {
      parser: tsParser,
      parserOptions: {
        sourceType: "module",
        ecmaVersion: "latest",
        //  project: ['./tsconfig.json'],   // ← uncomment if you need it
      },
    },
    plugins: {
      "@typescript-eslint": tsPlugin, // ← register the object exactly once
    },
    rules: {
      // Flag unused variables / args unless they start with "_"
      "@typescript-eslint/no-unused-vars": [
        "error",
        {
          vars: "all",
          args: "all",
          ignoreRestSiblings: true,
          varsIgnorePattern: "^_",
          argsIgnorePattern: "^_",
          caughtErrors: "all",
          caughtErrorsIgnorePattern: "^_",
          destructuredArrayIgnorePattern: "^_",
        },
      ],
      // Enforce named interface for destructured parameter types
      "@typescript-eslint/consistent-type-definitions": ["error", "interface"],
      // Defer unused‑var detection to the TypeScript‑aware version
      "no-unused-vars": "off",
      // 🚫 forbid   const fn = ({x}: {x: string}) => {}
      // ✅ allow     const fn = ({x}: MyProps) => {}
      "no-restricted-syntax": [
        "error",
        {
          selector: "ObjectPattern > TSTypeAnnotation > TSTypeLiteral",
          message:
            "Inline object type literals are not allowed in parameters – use a named interface or type alias instead.",
        },
      ],
    },
  },
];