Web: improve WhatsApp error formatting

src/web/session.ts

@@ -186,14 +186,88 @@ export function getStatusCode(err: unknown) {
   );
 }
 
+function safeStringify(value: unknown, limit = 800): string {
+  try {
+    const seen = new WeakSet<object>();
+    const raw = JSON.stringify(
+      value,
+      (_key, v) => {
+        if (typeof v === "bigint") return v.toString();
+        if (typeof v === "function") return `[Function ${(v as Function).name || "anonymous"}]`;
+        if (typeof v === "object" && v) {
+          if (seen.has(v)) return "[Circular]";
+          seen.add(v);
+        }
+        return v;
+      },
+      2,
+    );
+    if (!raw) return String(value);
+    return raw.length > limit ? `${raw.slice(0, limit)}…` : raw;
+  } catch {
+    return String(value);
+  }
+}
+
+function extractBoomDetails(err: unknown): {
+  statusCode?: number;
+  error?: string;
+  message?: string;
+} | null {
+  if (!err || typeof err !== "object") return null;
+  const output = (err as { output?: unknown })?.output as
+    | { statusCode?: unknown; payload?: unknown }
+    | undefined;
+  if (!output || typeof output !== "object") return null;
+  const payload = (output as { payload?: unknown }).payload as
+    | { error?: unknown; message?: unknown; statusCode?: unknown }
+    | undefined;
+  const statusCode =
+    typeof (output as { statusCode?: unknown }).statusCode === "number"
+      ? ((output as { statusCode?: unknown }).statusCode as number)
+      : typeof payload?.statusCode === "number"
+        ? (payload.statusCode as number)
+        : undefined;
+  const error = typeof payload?.error === "string" ? payload.error : undefined;
+  const message =
+    typeof payload?.message === "string" ? payload.message : undefined;
+  if (!statusCode && !error && !message) return null;
+  return { statusCode, error, message };
+}
+
 export function formatError(err: unknown): string {
   if (err instanceof Error) return err.message;
   if (typeof err === "string") return err;
-  const status = getStatusCode(err);
+  if (!err || typeof err !== "object") return String(err);
+
+  // Baileys frequently wraps errors under `error` with a Boom-like shape.
+  const boom =
+    extractBoomDetails(err) ??
+    extractBoomDetails((err as { error?: unknown })?.error) ??
+    extractBoomDetails((err as { lastDisconnect?: { error?: unknown } })?.lastDisconnect?.error);
+
+  const status = boom?.statusCode ?? getStatusCode(err);
   const code = (err as { code?: unknown })?.code;
-  if (status || code)
-    return `status=${status ?? "unknown"} code=${code ?? "unknown"}`;
-  return String(err);
+
+  const messageCandidates = [
+    boom?.message,
+    typeof (err as { message?: unknown })?.message === "string"
+      ? ((err as { message?: unknown }).message as string)
+      : undefined,
+    typeof (err as { error?: { message?: unknown } })?.error?.message === "string"
+      ? ((err as { error?: { message?: unknown } }).error?.message as string)
+      : undefined,
+  ].filter((v): v is string => Boolean(v && v.trim().length > 0));
+  const message = messageCandidates[0];
+
+  const pieces: string[] = [];
+  if (typeof status === "number") pieces.push(`status=${status}`);
+  if (boom?.error) pieces.push(boom.error);
+  if (message) pieces.push(message);
+  if (code !== undefined && code !== null) pieces.push(`code=${String(code)}`);
+
+  if (pieces.length > 0) return pieces.join(" ");
+  return safeStringify(err);
 }
 
 export async function webAuthExists() {