Howto Fix TypeScript Error “Did you intend to use it as a type annotation?”

The most obvious way to try to assign a type to a TypeScript object is wrong and syntactically it renames the value of a key.

Wrong:

handleStuff: ({ file: File }) => void;

Error:

/app # npx tsc --noEmit && eslint ./**/*.ts{,x}
components/MyComponent.tsx:37:27 - error TS2842: 'File' is an unused renaming of 'file'. Did you intend to use it as a type annotation?

37   handleStuff: ({ file: File }) => void;
                             ~~~~

  components/MyComponent.tsx:37:33
    37   handleStuff: ({ file: File }) => void;
                                       ~
    We can only write a type for 'file' by adding a type for the entire parameter here.

Good:

handleStuff: ({ file }: { file: File }) => void;

Or you can define a separate type.

No error. That’s all.

Howto Fix TypeScript Error “Did you intend to use it as a type annotation?”

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