.eslintrc.json

{
  "env": {
    "browser": false,
    "es6": true,
    "node": true
  },
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "project": "tsconfig.json",
    "sourceType": "module"
  },
  "overrides": [
    {
      "files": ["**/*.ts"] //ignore .js files
    }
  ],
  "plugins": ["@typescript-eslint", "jest"],
  "extends": [
    "eslint:recommended",
    "plugin:@typescript-eslint/eslint-recommended",
    "plugin:@typescript-eslint/recommended",
    "prettier"
  ],
  "rules": {
    "quotes": ["error", "double"],
    "object-curly-spacing": ["error", "always"],
    "@typescript-eslint/explicit-function-return-type": "error",
    "no-var": "error",
    "padding-line-between-statements": [
      "error",
      { "blankLine": "always", "prev": "block-like", "next": "function" }
    ],
    "space-infix-ops": "error",
    "spaced-comment": "error",
    "arrow-spacing": "error",
    "@typescript-eslint/naming-convention": [
      "error",
      { "selector": "class", "format": ["StrictPascalCase"] },
      { "selector": "interface", "format": ["StrictPascalCase"] },
      {
        "selector": "classProperty",
        "format": ["camelCase"],
        "leadingUnderscore": "allow"
      },
      { "selector": "objectLiteralProperty", "format": null },
      {
        "selector": "default",
        "format": ["strictCamelCase"],
        "leadingUnderscore": "allow"
      } //this must be the last rule
    ]
  }
}