Cannot get Array.prototype.includes to work in Typescript 2.0

Question

I am using typescript@next (version 2.1.0-dev.20160812 to be specific).

I am getting errors when trying to use Arrays.prototype.includes.

For instance this code

let myItems: Array<string>;
let exists: boolean = myItems.includes('blah');

Generates the following error:

Property 'includes' does not exist on type 'string[]'.at line 124 col 26

This is my tsconfig.json:

{
  "compileOnSave": true,
  "compilerOptions": {
    "module": "es6",
    "target": "es6",
    "moduleResolution": "node",
    "allowSyntheticDefaultImports": true,
    "noImplicitAny": true,
    "sourceMap": true,
    "outDir": "ts-build",
    "jsx": "preserve"
  },
  "exclude": [
    "node_modules"
  ]
}

Answer 1

I fixed this by adding lib:["es2016", "dom"] to the compiler options in tsconfig.json

Answer 2

You can add "es2016.array.include" to the compilerOptions

Answer 3

I added lib:["es2017", "dom"] to compilerOptions in tsconfig.json. For more clarification, check out this github issue