forgive my ignorance but I am trying to implement a fetch in TypeScript and I have been going through the examples but cannot get it to compile. I am new to TypeScript and Promise and I found this example:
How to use fetch in typescript
And I am trying to implement this:
private api<T>(url: string): Promise<T> {
return fetch(url)
.then(response => {
if (!response.ok) {
throw new Error(response.statusText)
}
return response.json<T>()
})
}
However the compiler shows the error:
[ts] Expected 0 type arguments, but got 1.
I am not sure what the problem is but basically I am trying to implement a class which wraps the API calls to return an array of items and I have experimented with async/await and nothing seems to quite work. Any help would be greatly appreciated.
Seems that signature is not there anymore, Instead use this code:
response.json().then(data => data as T);
Yeah, that will return you a strong typed data. Below the complete code snipped.
private api<T>(url: string): Promise<T> {
return fetch(url)
.then(response => {
if (!response.ok) {
throw new Error(response.statusText)
}
return response.json().then(data => data as T);
})
}
Got the same error with Express when I forgot this import:
import { Request, Response } from 'express';
The complete example becomes:
// controllers/my-controller.ts
import { Request, Response } from 'express';
export const someMethod = async (req: Request, res: Response) => {
// ...
}
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With