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

typescript async-await
Sedric Heidarizarei picture Sedric Heidarizarei · Apr 22, 2017 · Viewed 67.3k times · Source

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?

Answer

unional picture unional · Apr 22, 2017

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

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