Improve retry failure handling

Fixes #1388

src/apiutils.nim

@@ -182,10 +182,12 @@ template fetchImpl(result, fetchBody) {.dirty.} =
 
 template retry(bod) {.dirty.} =
   var session: Session
+  var retrySuccess = false
   for i in 0 ..< maxRetries:
     try:
       session = nil
       bod
+      retrySuccess = true
       break
     except RateLimitError:
       let api = if session.isNil: req.cookie.endpoint
@@ -199,6 +201,8 @@ template retry(bod) {.dirty.} =
       session = nil
       if retryDelayMs > 0:
         await sleepAsync(retryDelayMs)
+  if not retrySuccess:
+    raise rateLimitError()
 
 proc fetch*(req: ApiReq): Future[JsonNode] {.async.} =
   retry:

src/redis_cache.nim

@@ -144,9 +144,10 @@ proc getCachedUsername*(userId: string): Future[string] {.async.} =
   else:
     let user = await getGraphUserById(userId)
     result = user.username
-    await setEx(key, baseCacheTime, result)
-    if result.len > 0 and user.id.len > 0:
-      await all(cacheUserId(result, user.id), cache(user))
+    if result.len > 0:
+      await setEx(key, baseCacheTime, result)
+      if user.id.len > 0:
+        await all(cacheUserId(result, user.id), cache(user))
 
 # proc getCachedTweet*(id: int64): Future[Tweet] {.async.} =
 #   if id == 0: return