Add startDatabase.js to .gitignore exceptions

Co-authored-by: imnasnainaec <6411521+imnasnainaec@users.noreply.github.com>

Author: Copilot

.gitignore

@@ -35,6 +35,7 @@ scripts/*.js
 !scripts/frontendScripts.js
 !scripts/jestTest.js
 !scripts/setupMongo.js
+!scripts/startDatabase.js
 *.log
 *-debug.log*
 *-error.log*

scripts/startDatabase.js

@@ -0,0 +1,67 @@
+"use strict";
+
+const { spawn, spawnSync } = require("child_process");
+const { ensureDir } = require("fs-extra");
+
+const dbPath = "./mongo_database";
+const replSetName = "rs0";
+const maxAttempts = 30;
+const retryInterval = 1000; // ms
+
+async function waitForMongo() {
+  for (let i = 0; i < maxAttempts; i++) {
+    const result = spawnSync("mongosh", [
+      "--eval",
+      "db.adminCommand('ping')",
+      "--quiet",
+    ]);
+    if (result.status === 0) {
+      return true;
+    }
+    await new Promise((resolve) => setTimeout(resolve, retryInterval));
+  }
+  return false;
+}
+
+async function initReplicaSet() {
+  const result = spawnSync(
+    "mongosh",
+    ["--eval", "try { rs.status() } catch(e) { rs.initiate() }", "--quiet"],
+    { stdio: "inherit" }
+  );
+  return result.status === 0;
+}
+
+async function main() {
+  await ensureDir(dbPath);
+
+  const mongod = spawn("mongod", [`--dbpath=${dbPath}`, "--replSet", replSetName], {
+    stdio: "inherit",
+  });
+
+  mongod.on("error", (err) => {
+    console.error(`mongod error: ${err.message}`);
+    process.exit(1);
+  });
+
+  const ready = await waitForMongo();
+  if (ready) {
+    await initReplicaSet();
+  } else {
+    console.error("MongoDB did not start in time");
+  }
+
+  process.on("SIGINT", () => {
+    mongod.kill("SIGINT");
+  });
+  process.on("SIGTERM", () => {
+    mongod.kill("SIGTERM");
+  });
+
+  await new Promise((resolve) => mongod.on("close", (code) => resolve(code)));
+}
+
+main().catch((err) => {
+  console.error(err);
+  process.exit(1);
+});