test: add stable leaderboard regression coverage

package.json

@@ -29,7 +29,8 @@
     "start": "npm run build && NODE_ENV=development webpack-dev-server --host 0.0.0.0 --open --hot --config build/webpack.config.js",
     "build": "npm --prefix admin run build && NODE_ENV=production webpack --config build/webpack.config.js",
     "serve": "cd src/server && NODE_ENV=development node app.js",
-    "lint": "eslint ."
+    "lint": "eslint .",
+    "test": "node --test \"test/**/*.test.js\""
   },
   "husky": {
     "hooks": {

test/README.md

@@ -0,0 +1,26 @@
+# Regression tests
+
+This directory holds automated regression tests for stable leaderboard behavior.
+
+`leaderboard-e2e.test.js` starts the current server code against a fixed Rocket.Chat snapshot and verifies that `/stats`, `/rank`, and selected `/contributor` and `/rank?username=` responses still match the checked-in expected output.
+
+Node version used:
+
+- Node.js `v25.4.0`
+
+Fixtures:
+
+- `../contrib/rocketchat/gsoc/2025/gsoc2025final.json` is the canonical snapshot used as the fixed leaderboard input.
+- `fixtures/gsoc2025final.expected.json` is the checked-in golden output generated from the current stable ranking logic and used for regression comparisons.
+
+Run from the repo root:
+
+```bash
+npm i
+npm --prefix src/server install
+npm test
+```
+
+Note: `npm i` at the repo root installs only root dependencies. The regression test boots `src/server/app.js`, so `src/server` dependencies must also be installed before running `npm test`.
+
+The test itself uses the env/path override support already available in the upstream dotenv-based server setup (`CONFIG_PATH`, `DATA_PATH`, `LOG_PATH`, `ADMINDATA_PATH`, `CONFIG_BACKUP_PATH`, `SERVER_PORT`) and does not require additional source changes under `src/server`.

test/fixtures/gsoc2025final.config.json

@@ -0,0 +1,12 @@
+{
+    "organization": "RocketChat",
+    "organizationHomepage": "https://rocket.chat/",
+    "organizationGithubUrl": "https://github.com/RocketChat",
+    "authToken": "",
+    "adminPassword": "123456",
+    "delay": "10",
+    "serverPort": "62050",
+    "contributors": [],
+    "startDate": "2024-12-01",
+    "includedRepositories": []
+}