eslint-config-standardize/lib/eslintrc-ts.json

My personal configuration based on StandardJS, ready for JavaScript and TypeScript

{
  "parser": "@typescript-eslint/parser",
  "parserOptions": { "warnOnUnsupportedTypeScriptVersion": false },
  "plugins": ["@typescript-eslint"],
  "settings": {
    "import/extensions": [
      ".js",
      ".jsx",
      ".mjs",
      ".android.js",
      ".ios.js",
      ".web.js",
      ".ts",
      ".tsx",
      ".d.ts"
    ],
    "import/resolver": {
      "node": {
        "extensions": [
          ".js",
          ".jsx",
          ".mjs",
          ".android.js",
          ".ios.js",
          ".web.js",
          ".ts",
          ".tsx",
          ".d.ts"
        ]
      }
    },
    "import/parsers": { "@typescript-eslint/parser": [".ts", ".tsx", ".d.ts"] }
  },
  "rules": {
    "camelcase": "off",
    "no-use-before-define": "off",
    "@typescript-eslint/naming-convention": [
      "warn",
      {
        "selector": ["typeLike", "enum"],
        "format": ["PascalCase", "UPPER_CASE"],
        "leadingUnderscore": "forbid",
        "trailingUnderscore": "allow"
      },
      {
        "selector": ["function", "method"],
        "format": ["camelCase"],
        "leadingUnderscore": "allow",
        "trailingUnderscore": "allow"
      },
      {
        "selector": ["accessor", "classMethod", "classProperty", "parameterProperty"],
        "format": ["camelCase"],
        "modifiers": ["private"],
        "leadingUnderscore": "require",
        "trailingUnderscore": "allow"
      },
      {
        "selector": "classMethod",
        "format": null,
        "filter": { "regex": "^UNSAFE_[a-z]", "match": true }
      }
    ],
    "@typescript-eslint/no-use-before-define": [
      "error",
      {
        "classes": true,
        "enums": true,
        "functions": false,
        "typedefs": false,
        "variables": false
      }
    ]
  },
  "overrides": [
    {
      "files": ["**/*.ts", "**/*.tsx"],
      "rules": {
        "default-param-last": "off",
        "no-array-constructor": "off",
        "no-dupe-class-members": "off",
        "no-duplicate-imports": "off",
        "no-redeclare": "off",
        "no-undef": "off",
        "no-unused-expressions": "off",
        "no-unused-vars": "off",
        "import/export": "off",
        "import/named": "off",
        "import/no-named-as-default": "off",
        "@typescript-eslint/adjacent-overload-signatures": "error",
        "@typescript-eslint/ban-types": "error",
        "@typescript-eslint/consistent-type-assertions": [
          "error",
          { "assertionStyle": "as", "objectLiteralTypeAssertions": "allow-as-parameter" }
        ],
        "@typescript-eslint/default-param-last": "error",
        "@typescript-eslint/member-delimiter-style": [
          "error",
          {
            "multiline": { "delimiter": "none" },
            "singleline": { "delimiter": "semi", "requireLast": false }
          }
        ],
        "@typescript-eslint/no-array-constructor": "error",
        "@typescript-eslint/no-dupe-class-members": "error",
        "@typescript-eslint/no-duplicate-imports": "error",
        "@typescript-eslint/no-for-in-array": "error",
        "@typescript-eslint/no-inferrable-types": "error",
        "@typescript-eslint/no-misused-new": "error",
        "@typescript-eslint/no-parameter-properties": "error",
        "@typescript-eslint/no-redeclare": "error",
        "@typescript-eslint/no-unused-expressions": [
          "error",
          { "allowShortCircuit": true, "allowTernary": true, "allowTaggedTemplates": true }
        ],
        "@typescript-eslint/no-var-requires": "error",
        "@typescript-eslint/prefer-namespace-keyword": "error"
      }
    }
  ]
}