fetchStatus: check the fetch error

src/masto/base.ts

@@ -1,19 +1,20 @@
 import { createCacheBucket } from "~platform/cache";
+import { MastoHttpError, MastoTimeoutError, MastoUnexpectedError } from "masto";
 
-export const CACHE_BUCKET_NAME = "mastodon"
+export const CACHE_BUCKET_NAME = "mastodon";
 
 export const cacheBucket = /* @__PURE__ */ createCacheBucket(CACHE_BUCKET_NAME);
 
-export function toSmallCamelCase<T>(object: T) :T {
+export function toSmallCamelCase<T>(object: T): T {
   if (!object || typeof object !== "object") {
     return object;
   } else if (Array.isArray(object)) {
-    return object.map(toSmallCamelCase) as T
+    return object.map(toSmallCamelCase) as T;
   }
 
   const result = {} as Record<keyof any, unknown>;
   for (const k in object) {
-    const value = toSmallCamelCase(object[k])
+    const value = toSmallCamelCase(object[k]);
     const nk =
       typeof k === "string"
         ? k.replace(/_(.)/g, (_, match) => match.toUpperCase())
@@ -23,3 +24,61 @@ export function toSmallCamelCase<T>(object: T) :T {
 
   return result as T;
 }
+
+function contentTypeOf(headers: Headers) {
+  const raw = headers.get("Content-Type")?.replace(/\s*;.*$/, "");
+  if (!raw) {
+    return;
+  }
+
+  return raw;
+}
+
+/**
+ * Wrpas the error reason into masto's errors:
+ * {@link MastoHttpError} if the reason is a {@link Response},
+ * {@link MastoTimeoutError} if the reason is a timeout error.
+ *
+ * @throws If the reason is unexpected, {@link MastoUnexpectedError} will be thrown.
+ */
+export async function wrapsError(reason: Response): Promise<MastoHttpError>;
+export async function wrapsError(reason: {
+  name: "TimeoutError";
+}): Promise<MastoTimeoutError>;
+export async function wrapsError<T>(reason: T): Promise<T>;
+
+export async function wrapsError(reason: unknown) {
+  if (reason instanceof Response) {
+    const contentType = contentTypeOf(reason.headers);
+    if (!contentType) {
+      throw new MastoUnexpectedError(
+        "The server returned data with an unknown encoding. The server may be down",
+      );
+    }
+
+    const data = await reason.json();
+    const {
+      error: message,
+      errorDescription,
+      details,
+      ...additionalProperties
+    } = data;
+
+    return new MastoHttpError(
+      {
+        statusCode: reason.status,
+        message,
+        description: errorDescription,
+        details,
+        additionalProperties,
+      },
+      { cause: reason },
+    );
+  }
+
+  if (reason && (reason as { name?: string }).name === "TimeoutError") {
+    return new MastoTimeoutError("Request timed out", { cause: reason });
+  }
+
+  return reason;
+}

src/masto/statuses.ts

@@ -1,12 +1,7 @@
 import { CachedFetch } from "~platform/cache";
-import { cacheBucket, toSmallCamelCase } from "./base";
-import {
-  isAccountKey,
-  type RemoteServer,
-} from "../accounts/stores";
-import type { mastodon } from "masto";
-
-
+import { cacheBucket, toSmallCamelCase, wrapsError } from "./base";
+import { isAccountKey, type RemoteServer } from "../accounts/stores";
+import { type mastodon } from "masto";
 
 export const fetchStatus = /* @__PURE__ */ new CachedFetch(
   cacheBucket,
@@ -23,8 +18,15 @@ export const fetchStatus = /* @__PURE__ */ new CachedFetch(
     };
   },
   async (response) => {
-    return toSmallCamelCase(
-      await response.json(),
-    ) as unknown as mastodon.v1.Status;
+    try {
+      if (!response.ok) {
+        throw response;
+      }
+      return toSmallCamelCase(
+        await response.json(),
+      ) as unknown as mastodon.v1.Status;
+    } catch (reason) {
+      throw wrapsError(reason);
+    }
   },
 );