add types to a javascript when using typescript - 07-12-21
Today I had a .js file that I needed to import into the rest of a TypeScript app but could not convert it to a .ts file. To get around this limitation I added an accompanying .d.ts file.
countryConfig.js
const countries = [
{
code: 'de',
domainExtension: '.de'
},
...
];
exports.countries = countries;
countryConfig.d.ts
interface Country {
code: string;
domainExtension: string;
}
export const countries: Array<Country>;
app.ts
import countries from './countryConfig'
...
source: https://www.typescriptlang.org/docs/handbook/declaration-files/templates/module-d-ts.html