web_lib

Common web application libraries
git clone https://radroots.dev/git/web_lib.git
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fetch.ts (1239B)

      1 export type HttpFetch = (input: RequestInfo | URL, init?: RequestInit) => Promise<Response>;
      2 
      3 export type FetchJsonErrorKind = "http" | "network" | "parse";
      4 
      5 export type FetchJsonError = {
      6     ok: false;
      7     kind: FetchJsonErrorKind;
      8     url: string;
      9     message: string;
     10     status?: number;
     11     status_text?: string;
     12 };
     13 
     14 export type FetchJsonResult<T> = { ok: true; data: T } | FetchJsonError;
     15 
     16 export async function fetch_json<T>(fetch_fn: HttpFetch, url: string): Promise<FetchJsonResult<T>> {
     17     let res: Response;
     18     try {
     19         res = await fetch_fn(url);
     20     } catch (error) {
     21         const message = error instanceof Error ? error.message : "network_error";
     22         return { ok: false, kind: "network", url, message };
     23     }
     24 
     25     if (!res.ok) {
     26         return {
     27             ok: false,
     28             kind: "http",
     29             url,
     30             message: res.statusText || "http_error",
     31             status: res.status,
     32             status_text: res.statusText
     33         };
     34     }
     35 
     36     try {
     37         const data: T = await res.json();
     38         return { ok: true, data };
     39     } catch (error) {
     40         const message = error instanceof Error ? error.message : "parse_error";
     41         return { ok: false, kind: "parse", url, message };
     42     }
     43 }