feat(api): add error_type field and HTTP status codes for errors

- Add optional error_type parameter to respJsonError template for reliable
  client-side error detection
- Add httpCode parameter to return proper HTTP status codes
- Use HTTP 404 for not_found errors (tweet/user not found)
- Use "not_found" error_type for tweet and user not found errors

This allows clients to:
1. Check error_type === 'not_found' instead of parsing error messages
2. Rely on HTTP status codes for proper REST semantics

Example error response:
HTTP/1.1 404 Not Found
{
  "code": -1,
  "error": "Tweet not found",
  "error_type": "not_found"
}

Author: swkatmask

src/jsons/status.nim

@@ -60,7 +60,7 @@ proc createJsonApiStatusRouter*(cfg: Config) =
         var error = "Tweet not found"
         if conv != nil and conv.tweet != nil and conv.tweet.tombstone.len > 0:
           error = conv.tweet.tombstone
-        respJsonError error
+        respJsonError(error, "not_found", Http404)
 
       respJsonSuccess formatConversationAsJson(conv)
 

src/jsons/timeline.nim

@@ -121,7 +121,7 @@ proc createJsonApiTimelineRouter*(cfg: Config) =
       if username.len > 0:
         respJsonSuccess formatUserName(username)
       else:
-        respJsonError "User not found"
+        respJsonError("User not found", "not_found", Http404)
 
     get "/api/@name/profile":
       cond @"name" notin ["pic", "gif", "video", "search", "settings", "login",
@@ -135,7 +135,7 @@ proc createJsonApiTimelineRouter*(cfg: Config) =
         query.fromUser = names
 
       var profile = await fetchProfile("", query, skipRail = false)
-      if profile.user.username.len == 0: respJsonError "User not found"
+      if profile.user.username.len == 0: respJsonError("User not found", "not_found", Http404)
 
       respJsonSuccess formatProfileAsJson(profile)
 
@@ -160,6 +160,6 @@ proc createJsonApiTimelineRouter*(cfg: Config) =
         respJsonSuccess formatTimelineAsJson(timeline)
       else:
         var profile = await fetchProfile(after, query, skipRail = true)
-        if profile.tweets.content.len == 0: respJsonError "User not found"
+        if profile.tweets.content.len == 0: respJsonError("User not found", "not_found", Http404)
         profile.tweets.beginning = true
         respJsonSuccess formatTimelineAsJson(profile.tweets)

src/routes/router_utils.nim

@@ -53,12 +53,14 @@ template respJsonSuccess*(data: JsonNode) =
   }
   resp $successResponse, "application/json"
 
-template respJsonError*(message: string) =
-  let errorResponse = %*{
+template respJsonError*(message: string, errorType: string = "", httpCode: HttpCode = Http200) =
+  var errorResponse = %*{
     "code": -1,
     "error": message
   }
-  resp $errorResponse, "application/json"
+  if errorType.len > 0:
+    errorResponse["error_type"] = %errorType
+  resp httpCode, $errorResponse, "application/json"
 
 template respJsonNull*() =
   let nullResponse = newJNull()