Smaller wrapper over fetch

api-fetch-helper.ts

export let API_BASE: string = '/api/v1/';

export type FetchBodyType = Blob | Int8Array | Int16Array | Int32Array | Uint8Array |
	Uint16Array | Uint32Array | Uint8ClampedArray | Float32Array | Float64Array |
	DataView | ArrayBuffer | FormData | string | null;

export type PayloadFn = (h: Headers) => FetchBodyType;

export type PayloadType = Blob | FormData | string | object | PayloadFn;

export const Fetch = async (url: string, method: string = 'GET', payload?: PayloadType): Promise<Response> => {
	const req: RequestInit = {
		method,
		credentials: 'same-origin',
		redirect: 'follow',
		cache: 'no-cache',
		referrerPolicy: 'origin-when-cross-origin',
		mode: !url.startsWith('/') ? 'cors' : undefined,
		headers: new Headers({
			Accept: 'application/json',
		}),
	};

	const h = (req.headers! as Headers);
	if (payload instanceof FormData || payload instanceof Blob) {
		req.body = payload;
	} else if (typeof payload === 'string') {
		req.body = payload;
	} else if (typeof payload === 'function') {
		req.body = payload(h);
	} else if(payload != null) {
		h.set('Content-Type', h.get('Accept') as string);
		req.body = JSON.stringify(payload);
	}

	return await fetch(new Request(url, req));
};

export const FetchJSON = async <T>(url: string, method: string = 'GET', payload?: PayloadType): Promise<T> => {
	const resp = await Fetch(url, method, payload);
	return (await resp.json()) as T;
};

export const Get = <T>(ep: string) => FetchJSON<T>(API_BASE + ep);
export const Post = <T>(ep: string, payload?: PayloadType) => FetchJSON<T>(API_BASE + ep, 'POST', payload);
export const Put = <T>(ep: string, payload?: PayloadType) => FetchJSON<T>(API_BASE + ep, 'PUT', payload);
export const Delete = <T>(ep: string, payload?: PayloadType) => FetchJSON<T>(API_BASE + ep, 'DELETE', payload);