Added rank helpers for computing rank, hooked up to account migrator, with bonus tests

.eslintrc.json

@@ -35,6 +35,9 @@
     "import/order": "off",
     "simple-import-sort/sort": "error",
 
+    // unary operators are ok
+    "no-plusplus": "off",
+
     // Using a type system makes it safe enough to spread props
     "react/jsx-props-no-spreading": "off",
 

packages/backend/package.json

@@ -12,7 +12,8 @@
     "typecheck": "yarn build",
     "precommit": "yarn lint-staged",
     "generate": "graphql-codegen --config=codegen.yml",
-    "lintfix": "eslint --fix"
+    "lintfix": "eslint --fix",
+    "test": "tsdx test --passWithNoTests"
   },
   "author": "",
   "license": "ISC",

packages/backend/src/handlers/actions/migrateSourceCredAccounts/handler.ts

@@ -10,9 +10,9 @@ import {
   Player_Constraint,
   Player_Insert_Input,
   Player_Update_Column,
-  PlayerRank_Enum,
 } from '../../../lib/autogen/hasura-sdk';
 import { client } from '../../../lib/hasuraClient';
+import { computeRank } from '../../../lib/rankHelpers';
 import { AddressBookEntry, SCAccountsData, SCAlias } from './types';
 
 const ACCOUNTS_FILE =
@@ -69,16 +69,6 @@ const parseAlias = (alias: SCAlias) => {
   }
 };
 
-const RANKS = [
-  PlayerRank_Enum.Diamond,
-  PlayerRank_Enum.Platinum,
-  PlayerRank_Enum.Gold,
-  PlayerRank_Enum.Silver,
-  PlayerRank_Enum.Bronze,
-];
-
-const NUM_PLAYERS_PER_RANK = 10;
-
 export const migrateSourceCredAccounts = async (
   _: Request,
   res: Response,
@@ -115,12 +105,14 @@ export const migrateSourceCredAccounts = async (
 
       const addressEntry =
         discordId && addressBook.find((adr) => adr.discordId === discordId);
+
+      const rank = computeRank(index);
       return {
         ethereum_address: addressEntry && addressEntry.address,
         scIdentityId: a.account.identity.id,
         username: a.account.identity.name.toLowerCase(),
         totalXp: a.totalCred,
-        rank: RANKS[Math.floor(index / NUM_PLAYERS_PER_RANK)],
+        rank,
         discordId,
         mergedIdentityIds,
         Accounts: {

packages/backend/src/lib/rankHelpers.ts

@@ -0,0 +1,32 @@
+import { PlayerRank_Enum } from './autogen/hasura-sdk';
+
+export const RANKS = [
+  PlayerRank_Enum.Diamond,
+  PlayerRank_Enum.Platinum,
+  PlayerRank_Enum.Gold,
+  PlayerRank_Enum.Silver,
+  PlayerRank_Enum.Bronze
+]
+
+export const PLAYERS_PER_RANK = [7, 7, 7, 14, 21];
+
+// A summation of PLAYERS_PER_RANK.
+// This is the first index for which players will NOT be ranked, e.g.
+// the 56th player will be Bronze, and the 57th player will not be ranked.
+export const RANKED_CAP: number = PLAYERS_PER_RANK.reduce((sum, rankCount) => {
+  return sum + rankCount;
+}, 0);
+
+// Computes the rank for the given index. This would be the index corresponding
+// to all players ordered by total_xp DESC.
+export function computeRank(totalRankIndex: number): PlayerRank_Enum | null {
+  if (totalRankIndex >= RANKED_CAP) return null;
+  let indexSum = 0;
+  for (let i = 0; i < PLAYERS_PER_RANK.length; i++) {
+    indexSum += PLAYERS_PER_RANK[i];
+    if (totalRankIndex < indexSum) {
+      return RANKS[i];
+    }
+  }
+  return null;
+}

packages/backend/tests/lib/rankHelpers.test.ts

@@ -0,0 +1,26 @@
+import { PlayerRank_Enum } from '../../src/lib/autogen/hasura-sdk';
+import { computeRank, RANKED_CAP } from '../../src/lib/rankHelpers';
+
+describe('RANKED_CAP', () => {
+  it('should equal 56', () => {
+    expect(RANKED_CAP).toBe(56);
+  });
+});
+
+describe('computeRank', () => {
+  it('index 6 should be diamond', () => {
+    expect(computeRank(6)).toBe(PlayerRank_Enum.Diamond)
+  });
+  it('index 7 should be platinum', () => {
+    expect(computeRank(7)).toBe(PlayerRank_Enum.Platinum)
+  });
+  it('index 21 should be silver', () => {
+    expect(computeRank(21)).toBe(PlayerRank_Enum.Silver)
+  });
+  it('index 55 should be bronze', () => {
+    expect(computeRank(55)).toBe(PlayerRank_Enum.Bronze)
+  });
+  it('index 56 should not be ranked', () => {
+    expect(computeRank(56)).toBeNull();
+  });
+})