Usage

Install

npm install --save-dev eslint typescript @apify/eslint-config-ts @typescript-eslint/eslint-plugin @typescript-eslint/parser 

Usage with React

To make use of React types such as state, children etc. install:

npm i --save-dev @types/react

Edit .eslintrc

Add (or replace @apify/eslint-config package)

{
  "extends": "@apify/eslint-config-ts"
}

NOTE (from https://eslint.org/docs/developer-guide/shareable-configs):

When using scoped modules it is not possible to omit the eslint-config- prefix. Doing so would result in package naming conflicts, and thus in resolution errors in most of cases. For example a package named @scope/eslint-config-myconfig vs @scope/my-config, since both are valid scoped package names, the configuration should be specified as:

{
    "extends": "@scope/eslint-config-myconfig"
}

Create tsconfig.json

Create tsconfig.json file in the root of the project and add:

{}

List of all options https://www.typescriptlang.org/tsconfig

Example minimal setup (used on Web)

{
    "compilerOptions": {
        "skipLibCheck": true,
        "esModuleInterop": true,
        "jsx": "preserve",
        "noUnusedLocals": true,
        "noUnusedParameters": true
    },
    "exclude": [
        "node_modules",
    ],
    "include": [
        "**/*.ts",
        "**/*.tsx"
    ]
}

skipLibCheck: Skips typechecking of 3rd party libraries declaration files (extension .d.ts) since they may have different tsconfig

esModuleInterop: Allows eg "import React from 'react'" instead of "import * as React from 'react'"

jsx: Allows use of JSX tags

noUnusedLocals: Error on unused variables

noUnusedParameters: Error on unused function params

Edit lint npm script

Edit lint npm script to include .ts, .tsx files and to run typescript validation

"eslint --ext .js,.jsx,.ts,.tsx ; tsc --noemit"