ts An async function or method in ES5/ES3 requires the 'Promise' constructor

Hello I'm Using async/await in my TypeScript Project, But I Get this log:

[ts] An async function or method in ES5/ES3 requires the 'Promise' constructor. Make sure you have a declaration for the 'Promise' constructor or include 'ES2015' in your --lib option.

How Can I Solve That?

As the error message says, add lib: es2015 to your tsconfig.json

// tsconfig.json
{
  "compilerOptions": {
    "lib": [ "es2015" ]
  }
}

UPDATE: if this doesn't work for you, try this:

JetBrains IDE such as WebStorm, use its own implementation by default. Make sure you configure it to use TypeScript language service instead.

For Visual Studio, the project files and tsconfig.json are mutually exclusive. You will need to configure your project directly.

https://github.com/Microsoft/TypeScript/issues/3983#issuecomment-123861491

Try this package which contains type definitions for es6-promise

npm install --save @types/es6-promise

If you are on VS, delete the tsconfig.json and right click the project in Solution Explorer, then click on Properties->TypeScript Build in General change the followings

• ECMAScript version: ECMAScript 6

• Module System: ES2015

For me the error occurred in my testing files inside src/tests folder. Since I use ts-node for testing the .ts files directly, I excluded src/tests/* in my tsconfig.json. As soon as I deleted the line the error was gone (which makes sense in the end).

Just in case someone else is struggling with this in his testing files.

EDIT: Of course you need to configure your --lib option correctly as outlined in the accepted answer. My tsconfig.json --lib option works as following:

"lib": [
    "es2018",
    "dom"
]