eslint.config.mjs

// SPDX-FileCopyrightText: 2024 Gnuxie <Gnuxie@protonmail.com>
//
// SPDX-License-Identifier: CC0-1.0

import eslint from "@eslint/js";
import tseslint from "typescript-eslint";
import tsplugin from "@typescript-eslint/eslint-plugin";

// this configuration file stilli includes random shite from these directories
// and I do not understand why. It is one of the most frustraiting things
// my guess is that there is some hidden ambient config that is included
// full of eslint defaults that we can't intercept??
// I don't know, but it's one of the most frustraiting things ever.
const ignores = [
  "**/docs/**",
  "**/.husky/**",
  "**/coverage/**",
  "**/dist/**",
  "**/lib/**",
];

const rulesFromMPS = {
  "@typescript-eslint/explicit-function-return-type": "off",
  "@typescript-eslint/no-unused-vars": ["error", { argsIgnorePattern: "^_" }],
  // we implement a lot of interfaces that return promises with synchronous functions.
  "require-await": "off",
  "@typescript-eslint/require-await": "off",
  // we need never because our code can be wrong!
  "@typescript-eslint/restrict-template-expressions": [
    "error",
    { allowNever: true },
  ],
  // stylistic recommendation that doesn't play well with event emitter interfaces.
  "@typescript-eslint/unified-signatures": "off",
  // There are some compelling arguments for including this rule,
  // but other than using namespaces, we don't have granular enough modules
  // to be able to depend on their behaviour. This should be revisited.
  "@typescript-eslint/no-extraneous-class": "off",
  // We want to be able to create infinite loops.
  "@typescript-eslint/no-unnecessary-condition": [
    "error",
    { allowConstantLoopConditions: true },
  ],
};

export default tseslint.config({
  // This is a typescript-eslint configurartion for typescript files.
  // This will not work against js files.
  files: ["src/**/*.ts", "src/**/*.tsx", "test/**/*.ts", "test/**/*.tsx"],
  extends: [eslint.configs.recommended, ...tseslint.configs.strictTypeChecked],
  languageOptions: {
    parserOptions: {
      project: ["./tsconfig.json", "./test/tsconfig.json"],
    },
  },
  // This is needed in order to specify the desired behavior for its rules
  plugins: {
    "@typescript-eslint": tsplugin,
  },
  rules: {
    // Place to specify ESLint rules. Can be used to overwrite rules specified from the extended configs
    // e.g. "@typescript-eslint/explicit-function-return-type": "off",
    ...rulesFromMPS,

    // There is too much ambient `any` from the `matrix-bot-sdk` in our project to be able to use no-unsafe-*.
    // We would really love to be able to set this to `error`.
    "@typescript-eslint/no-unsafe-argument": "off",
    "@typescript-eslint/no-unsafe-member-access": "off",
    "@typescript-eslint/no-unsafe-assignment": "off",
    "@typescript-eslint/no-unsafe-return": "off",
    "@typescript-eslint/no-unsafe-call": "off",

    // We make the mistake of using `unknown` for caught and wrapped exceptions
    // in matrix-protection-suite...
    // which causes problems when we unwrap them.
    // We should probably change `Result` to throw when exception doesn't
    // implement error.
    "@typescript-eslint/only-throw-error": "off",

    "@typescript-eslint/unbound-method": ["error", { ignoreStatic: true }],

    "no-constant-condition": ["error", { checkLoops: "allExceptWhileTrue" }],
  },
  ignores: [...ignores, "**/*.js", "**/*.jsx"],
});