@passion_pi/fetch

Power by these stander API fetch URL URLSearchParams Headers Request Response AbortController.

Based on fetch API, support middleware, URLSearchParams and AbortController by default.

When you use fetch, it's maybe like this in every request:

``typescript
const promise = fetch("/api/xxx?name=Ash&name=Bob", {
method: "post",
headers: {
"Content-Type": "application/json",
Authorization: "Bearer Your token",
},
body: JSON.stringify({ a: 1 }),
}).then((res) => res.json());

try {
const val = await promise;
console.log(val);
} catch (err) {
console.error(err);
}
// Want to abort the request? You need to write more code!
`

This package will help you to simplify the code above.

`typescript
import { createFetch, jwt, json } from "@passion_pi/fetch";

// Will add Content-Type: application/json header
// Will add Authorization: Bearer Your token header
const myFetch = createFetch(json(), jwt({ token: () => "Your token" }));

const promise = myFetch<{ message: string }>({
url: "/api/xxx",
search: { name: ["Ash", "Bob"] },
method: "post",
body: { a: 1 },
});

// Want to abort the request? Just like this:
// promise.abort();
const [err, val] = await promise;
if (err) {
console.error(err);
} else {
console.log(val); // { message: 'some message from backend' }
}
`

There are only 2 main different in with fetch API:

1. fetch(input: URL, options: RequestInit) -> myFetch({ url, search, ...options }: Payload) will auto parse url + search to URL and options to RequestInit.

2. myFetch will return Promise<[Error, null, Meta]> or Promise<[null, T, Meta]> instead of Promise.

There are some features in this package:

- Middleware support like koa middleware
- search, same param with URLSearchParams and support Record type.
- body will be stringified to json if Content-Type is application/json and body is object.
- response will be parsed to json or text if Content-Type is application/json or text/plain
- abort method integrate by default

Want to write middleware? Just like this:

`typescript
import { createFetch, json, Middleware } from "@passion_pi/fetch";

const logUrl: Middleware = async (context, next) => {
const { url } = context;
console.log("Your request url is:", url.toString());
return next();
};
const getData: Middleware = async (context, next) => {
const [err, val, meta] = await next();
if (err) {
return [err, null, meta];
}
if (typeof val == "object") {
// if you want to get data field in response value
return [null, Reflect.get(val || {}, "data"), meta];
}
return [null, val, meta];
};
const getBlob: Middleware = async (context, next) => {
const { headers } = context;

const [err, val, meta] = await next();
if (err) {
return [err, null, meta];
}
if (headers.get("responseType") === "blob") {
return [null, await meta.response.clone().blob(), meta];
}
return [null, val, meta];
};

const myFetch = createFetch(json(), logUrl, getData, getBlob);
``