First commit

packages/lynqchat-js/src/lib/error.ts

@@ -0,0 +1,6 @@
+export default class lynqError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = "lynqError";
+  }
+}

packages/lynqchat-js/src/lib/fetch.ts

@@ -0,0 +1,56 @@
+import lynqError from "./error";
+
+export default async function lynqFetch(
+  origin: string,
+  retryCount: number,
+  waitingTime: number,
+  endpoint: string,
+  init?: RequestInit,
+) {
+  const waiting = (ms: number) =>
+    new Promise<void>(resolve => setTimeout(resolve, ms));
+  
+  let lastError;
+
+  for (let i = 0; i < retryCount; i++) {
+    try {
+      if (init?.signal?.aborted) {
+        throw new DOMException("Aborted", "AbortError");
+      }
+      
+      const req = await fetch(new URL(`/api/${endpoint}`, origin), init);
+
+      if (
+        Math.floor(req.status / 200) === 1 ||
+        Math.floor(req.status / 300) === 1
+      ) {
+        return req;
+      }
+      
+      if (Math.floor(req.status / 400) === 1)
+        throw new lynqError(`Client error: HTTP${req.status} - ${req.statusText}`);
+      
+      lastError = new Error(`Request failed: HTTP${req.status} - ${req.statusText}`);
+    } catch (err) {
+      if (err instanceof DOMException && err.name === "AbortError") {
+        throw err;
+      }
+      
+      if (
+        err instanceof lynqError &&
+        err.name === "Client error" &&
+        err.message.startsWith("HTTP4")
+      )
+        throw err;
+
+      lastError = err;
+    }
+
+    if (i < retryCount - 1) {
+      const waitTime = waitingTime * 2 ** i;
+      await waiting(waitTime);
+    }
+  }
+
+  throw lastError ?? new Error("Unknown Error");
+}