With the following code snippet I'm getting the following error: TypeScript error: 'route' implicitly has type 'any' because it does not have a type annotation and is referenced directly or indirectly in its own initializer. TS7022
const store = configureStore()
const renderWithRouter = (
ui: any,
{
route = '/', /* ERROR HERE */
history = createMemoryHistory({ initialEntries: [route] }),
} = {},
) => {
return {
...render(
<Provider store={store}><Router history={history}>{ui}</Router></Provider>,
),
history,
}
}
export default renderWithRouter
I was working in a completely section of the code and had to upgrade a package, and then all of a sudden this started complaining. (The packages were react-router-dom and @types/react-router-dom).
I'm not exactly sure how to get past this, and furthermore I'm a little confused by what's going on with the second parameter in the function. it looks like they were trying to identify a default empty parameter, however they've filled in values on the left hand side for route and history.
edit: I have resolved the issue by adding the following:
interface IRenderParams {
route: string | undefined;
history: MemoryHistory<any>
}
...
{
route = '/', /* ERROR HERE */
history = createMemoryHistory({ initialEntries: [route] }),
} = {} as IRenderParams
...
This resolves the issue, however, I still am not sure exactly why is this defined like this.
The error message you received is due to the fact that the route parameter is implicitly typed as any because it is used in the initialization of the history parameter, which has a specific type. This is because the type of route is not explicitly defined.
To fix this issue, you can explicitly define the type of the route parameter like so:
const renderWithRouter = ( ui: any, { route = '/', history = createMemoryHistory({ initialEntries: [route] }), }: { route?: string, history?: MemoryHistory<any> } = {}, ) => { return { ...render( <Provider store={store}><Router history={history}>{ui}</Router></Provider>, ), history, } }This will provide a default value for route as '/' and a type definition for the second parameter, including the type definition for the route parameter.
Regarding the second parameter, it is using destructuring with default values to define a default parameter for the function. If the function is called without the second parameter, it will default to an empty object {}. If the second parameter is passed, it will be destructured to extract the route and history parameters, and if they are not provided, they will default to the values on the right-hand side of the assignment.
By adding the as IRenderParams assertion, you are essentially telling TypeScript that the default parameter should be considered as an object of type IRenderParams. This allows you to avoid explicitly defining the types of the destructured properties. However, it's generally recommended to explicitly define the types whenever possible to make the code more readable and easier to maintain.