ui: add constant to error page

packages/hydrooj/package.json

@@ -1,6 +1,6 @@
 {
     "name": "hydrooj",
-    "version": "3.1.21",
+    "version": "3.1.22",
     "bin": "bin/hydrooj.js",
     "main": "src/loader",
     "module": "src/loader",

packages/hydrooj/src/service/bus.ts

@@ -64,9 +64,14 @@ export interface EventMap extends Record<string, any> {
     'handler/create': (thisArg: Handler) => VoidReturn
     'handler/init': (thisArg: Handler) => VoidReturn
     'handler/before-prepare/UserRegister': (thisArg: UserRegisterHandler) => VoidReturn
+    'handler/before-prepare': (thisArg: Handler) => VoidReturn
     'handler/before/UserRegister': (thisArg: UserRegisterHandler) => VoidReturn
+    'handler/before': (thisArg: Handler) => VoidReturn
     'handler/after/UserRegister': (thisArg: UserRegisterHandler) => VoidReturn
+    'handler/after': (thisArg: Handler) => VoidReturn
     'handler/finish/UserRegister': (thisArg: UserRegisterHandler) => VoidReturn
+    'handler/finish': (thisArg: Handler) => VoidReturn
+    'handler/error': (thisArg: Handler) => VoidReturn
     'handler/solution/get': (thisArg: ProblemSolutionHandler) => VoidReturn
 
     'discussion/before-add': (payload: Partial<DiscussionDoc>) => VoidReturn

packages/hydrooj/src/service/server.ts

@@ -725,6 +725,8 @@ async function handle(ctx, HandlerClass, checker) {
         await bail('handler/finish', h);
     } catch (e) {
         try {
+            await bail(`handler/error/${HandlerClass.name.replace(/Handler$/, '')}`, h);
+            await bail('handler/error', h);
             await h.onerror(e);
         } catch (err) {
             h.response.code = 500;