fix: extend linting

Mainly base our linting on `standard` and
`@typescript-eslint/recommended`.

.eslintrc.js

@@ -1,61 +1,55 @@
-module.exports = {
-  root: true,
+const defaultSettings = {
+  env: { es6: true, node: true },
+  extends: ["standard", "prettier"],
+  parser: "babel-eslint",
   rules: {
-    indent: "off",
-    "no-unused-vars": "off",
-    semi: [2, "always"],
-    "keyword-spacing": [2, { before: true, after: true }],
-    "space-before-blocks": [2, "always"],
-    "no-mixed-spaces-and-tabs": [2, "smart-tabs"],
-    "no-cond-assign": 0,
-    "no-empty": 0,
-    "object-shorthand": [2, "always"],
-    "no-const-assign": 2,
-    "no-class-assign": 2,
-    "no-this-before-super": 2,
-    "no-var": 2,
-    "no-unreachable": 2,
-    "valid-typeof": 2,
-    "quote-props": [2, "as-needed"],
-    "one-var": [2, "never"],
-    "prefer-arrow-callback": 2,
-    "prefer-const": [2, { destructuring: "all" }],
-    "arrow-spacing": 2,
-    "no-inner-declarations": 0,
-    "require-atomic-updates": "off",
-    quotes: "off",
-    "@typescript-eslint/quotes": ["error", "double"],
-    "@typescript-eslint/no-use-before-define": "off",
-    "@typescript-eslint/explicit-function-return-type": "off",
-    "@typescript-eslint/no-explicit-any": "off",
-    "@typescript-eslint/explicit-member-accessibility": "off",
-    "@typescript-eslint/no-object-literal-type-assertion": "off",
-    "@typescript-eslint/no-unused-vars": "off",
-    "@typescript-eslint/prefer-interface": "off",
-    "@typescript-eslint/no-non-null-assertion": "off",
-  },
-  env: {
-    es6: true,
-    browser: true,
-    node: true,
-    jest: true,
+    "no-unused-vars": [
+      "error",
+      {
+        args: "none",
+        ignoreRestSiblings: true,
+        vars: "all",
+        varsIgnorePattern: "^_+$",
+      },
+    ],
   },
+};
+
+const testSettings = {
+  env: { ...defaultSettings.env, jest: true },
+  files: ["tests/**/*.{js,jsx,mjs,ts,tsx}", "**/*.test.{js,jsx,mjs,ts,tsx}"],
+  rules: { ...defaultSettings.rules, "import/first": "off" },
+};
+
+const typescriptSettings = {
+  files: ["src/**/*.{ts,tsx}"],
   extends: [
-    "eslint:recommended",
     "plugin:@typescript-eslint/recommended",
-    // keep at the end
-    "plugin:prettier/recommended",
+    "prettier/@typescript-eslint",
   ],
+  parser: "@typescript-eslint/parser",
   parserOptions: {
-    ecmaVersion: 9,
-    sourceType: "module",
+    ecmaFeatures: { jsx: true },
+    ecmaVersion: 2020,
+    project: "./tsconfig.json",
+    warnOnUnsupportedTypeScriptVersion: false,
   },
-  overrides: [
-    {
-      files: ["*.js"],
-      rules: {
-        "@typescript-eslint/no-var-requires": "off",
+  plugins: ["@typescript-eslint"],
+  rules: {
+    ...defaultSettings.rules,
+    "@typescript-eslint/member-delimiter-style": [
+      "error",
+      {
+        multiline: { delimiter: "comma", requireLast: true },
+        singleline: { delimiter: "comma", requireLast: false },
       },
-    },
-  ],
+    ],
+    "@typescript-eslint/explicit-function-return-type": "off",
+    "@typescript-eslint/no-unused-vars": "error",
+  },
+};
+
+module.exports = {
+  ...defaultSettings,
+  overrides: [testSettings, typescriptSettings],
 };

jsconfig.json

@@ -0,0 +1,7 @@
+{
+  "compilerOptions": {
+    "allowSyntheticDefaultImports": true,
+    "target": "esnext"
+  },
+  "include": ["src/**/*", "test/**/*"]
+}