fix: make surveyCode uniqueness checks async (#94)

* fix: async helper functions

* chore: referral code -> survey code

Author: natalierobbins

server/src/database/survey/survey.controller.ts

@@ -20,11 +20,11 @@ export async function getParentSurveyCode(
  * @returns Array<string> - The generated child survey codes
  * @throws {Error} - Throws SURVEY_CODE_GENERATION_ERROR if unable to generate unique codes after 3 retries
  */
-export function generateUniqueChildSurveyCodes(): Array<string> {
+export async function generateUniqueChildSurveyCodes(): Promise<Array<string>> {
 	for (let retries = 0; retries < 3; retries++) {
-		const codes = Array.from({ length: 3 }, () =>
-			generateUniqueReferralCode()
-		);
+		const codes = await Promise.all(Array.from({ length: 3 }, () =>
+			generateUniqueSurveyCode()
+		));
 		// Enforce uniqueness within the array
 		if (isUniqueSurveyCodeArray(codes)) {
 			return codes;
@@ -51,11 +51,11 @@ function isUniqueSurveyCodeArray(codes: Array<string>): boolean {
  * @returns string - A unique 6-character alphanumeric code in uppercase
  * @throws {Error} - Throws SURVEY_CODE_GENERATION_ERROR if unable to generate unique code after 3 retries
  */
-export function generateUniqueReferralCode(): string {
+export async function generateUniqueSurveyCode(): Promise<string> {
 	for (let retries = 0; retries < 3; retries++) {
 		const code = Math.random().toString(36).substring(2, 8).toUpperCase();
 		// Enforce individual code uniqueness
-		if (isUniqueSurveyCode(code)) {
+		if (await isUniqueSurveyCode(code)) {
 			return code;
 		}
 	}
@@ -69,9 +69,9 @@ export function generateUniqueReferralCode(): string {
  * @param code - The survey code to check for uniqueness
  * @returns boolean - true if the code is unique, false if it already exists
  */
-function isUniqueSurveyCode(code: string): boolean {
+async function isUniqueSurveyCode(code: string): Promise<boolean> {
 	return (
-		Survey.findOne({ surveyCode: code }) === null &&
-		Survey.findOne({ childSurveyCodes: { $in: [code] } }) === null
+		await Survey.findOne({ surveyCode: code }) === null &&
+		await Survey.findOne({ childSurveyCodes: { $in: [code] } }) === null
 	);
 }

server/src/routes/v2/surveys.ts

@@ -5,7 +5,7 @@ import express, { NextFunction, Response } from 'express';
 import Survey, { ISurvey } from '@/database/survey/mongoose/survey.model';
 import {
 	generateUniqueChildSurveyCodes,
-	generateUniqueReferralCode,
+	generateUniqueSurveyCode,
 	getParentSurveyCode
 } from '@/database/survey/survey.controller';
 import {
@@ -209,7 +209,7 @@ router.post(
 			const surveyData: ISurvey = req.body;
 
 			// Generate unique child survey codes for the new survey
-			surveyData.childSurveyCodes = generateUniqueChildSurveyCodes();
+			surveyData.childSurveyCodes = await generateUniqueChildSurveyCodes();
 
 			// Resolve parent survey code
 			if (surveyData.surveyCode) {
@@ -230,7 +230,7 @@ router.post(
 			} else if (req.query.new === 'true') {
 				// If `new` query parameter is true, generate new survey code and set parent to seed
 				surveyData.parentSurveyCode = SYSTEM_SURVEY_CODE;
-				surveyData.surveyCode = generateUniqueReferralCode();
+				surveyData.surveyCode = await generateUniqueSurveyCode();
 			} else {
 				const err = errors.NO_SURVEY_CODE_PROVIDED;
 				return res.status(err.status).json({