core: admin can remove contestant before contest start (#1196)

packages/hydrooj/src/model/contest.ts

@@ -939,6 +939,12 @@ export async function attend(domainId: string, tid: ObjectId, uid: number, paylo
     return {};
 }
 
+export async function cancelAttend(domainId: string, tid: ObjectId, uid: number) {
+    await document.deleteMultiStatus(domainId, document.TYPE_CONTEST, { docId: tid, uid });
+    await document.inc(domainId, document.TYPE_CONTEST, tid, 'attend', -1);
+    return {};
+}
+
 export function getMultiStatus(domainId: string, query: any) {
     return document.getMultiStatus(domainId, document.TYPE_CONTEST, query);
 }
@@ -1148,6 +1154,7 @@ global.Hydro.model.contest = {
     getListStatus,
     getMultiStatus,
     attend,
+    cancelAttend,
     edit,
     del,
     get,