E0284: missing TypeScript type

In TypeScript, you can annotate the type of a variable by writing : after its name in its declaration. It is a syntax error to omit the type after ::

function api(endpoint: ): Promise<any> {
  // ...
}

To fix this error, write a type after the ::

function api(endpoint: string): Promise<any> {
  // ...
}

Alternatively, remove the ::

function api(endpoint): Promise<any> {
  // ...
}

Introduced in quick-lint-js version 2.9.0.

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