2 posts tagged with "types"

Linting with type information, also called "typed linting" or "type-aware linting", is the act of writing lint rules that use type information to understand your code. Typed linting rules as provided by typescript-eslint are the most powerful JavaScript/TypeScript linting in common use today.

In this blog post, we'll give a high-level overview of how linting with type information works, why it's so much more powerful than traditional linting, and some of the useful rules you can enable that use it.

import and export statements are core features of the JavaScript language. They were added as part of the ECMAScript Modules (ESM) specification, and now are generally available in most mainstream JavaScript environments, including all evergreen browsers and Node.js.

When writing TypeScript code with ESM, it can sometimes be desirable to import or export a type only in the type system. Code may wish to refer to a type, but not actually import or export a corresponding value.

Type-only imports and exports are not emitted as runtime code when code is transpiled to JavaScript. This brings up two questions:

• Why would you want to use these type-only imports and exports?
• How can you enforce a project use them whenever necessary?

Let's dig in!