Implement leaderboard ranking based on total points

src/lib/leaderboard/leaderboard.ts

@@ -0,0 +1,38 @@
+import type {
+  LeaderboardEntry,
+  Member,
+} from "./types";
+
+export function generateLeaderboard(
+  members: Member[],
+): LeaderboardEntry[] {
+  const sortedMembers = [...members].sort(
+    (a, b) => b.totalPoints - a.totalPoints,
+  );
+
+  const leaderboard: LeaderboardEntry[] = [];
+
+  let currentRank = 1;
+  let previousPoints: number | null = null;
+
+  for (const member of sortedMembers) {
+    if (
+      previousPoints !== null &&
+      member.totalPoints < previousPoints
+    ) {
+      currentRank++;
+    }
+
+    leaderboard.push({
+      rank: currentRank,
+      id: member.id,
+      name: member.name,
+      domain: member.domain,
+      totalPoints: member.totalPoints,
+    });
+
+    previousPoints = member.totalPoints;
+  }
+
+  return leaderboard;
+}

src/lib/leaderboard/seedData.ts

@@ -0,0 +1,40 @@
+import type { Member } from "./types";
+
+export const members: Member[] = [
+  {
+    id: 1,
+    name: "Alice",
+    domain: "Tech",
+    totalPoints: 200,
+  },
+  {
+    id: 2,
+    name: "Bob",
+    domain: "Design",
+    totalPoints: 150,
+  },
+  {
+    id: 3,
+    name: "Charlie",
+    domain: "Content",
+    totalPoints: 150,
+  },
+  {
+    id: 4,
+    name: "David",
+    domain: "Tech",
+    totalPoints: 100,
+  },
+  {
+    id: 5,
+    name: "Eva",
+    domain: "Design",
+    totalPoints: 100,
+  },
+  {
+    id: 6,
+    name: "Frank",
+    domain: "Marketing",
+    totalPoints: 60,
+  },
+];

src/lib/leaderboard/service.ts

@@ -0,0 +1,6 @@
+import { generateLeaderboard } from "./leaderboard";
+import { members } from "./seedData";
+
+export async function runLeaderboard() {
+  return generateLeaderboard(members);
+}

src/lib/leaderboard/test.ts

@@ -0,0 +1,11 @@
+import { runLeaderboard } from "./service";
+
+const leaderboard = await runLeaderboard();
+
+console.log(
+  JSON.stringify(
+    leaderboard,
+    null,
+    2,
+  ),
+);

src/lib/leaderboard/types.ts

@@ -0,0 +1,14 @@
+export type Member = {
+  id: number;
+  name: string;
+  domain: string;
+  totalPoints: number;
+};
+
+export type LeaderboardEntry = {
+  rank: number;
+  id: number;
+  name: string;
+  domain: string;
+  totalPoints: number;
+};