feat: lazy load discord groups page (#2291)

* feat: added pagination for lazy loading in the /groups route to load the discord groups asynchrounously instead of all at once

* feat: Implement pagination for lazy loading in

- Added feature-flag-based () lazy loading to .
- Introduced support for , , and __TEXT	__DATA	__OBJC	others	dec	hex query parameters for pagination.
- Validated query parameters and returned structured pagination metadata (, __TEXT	__DATA	__OBJC	others	dec	hex, , ).
- Updated response structure to include enriched group membership information.
- Modified test cases in :
  - Added tests for cursor-based lazy loading behavior.
  - Handled scenarios with and without cursors.
  - Verified error handling for database query failures.

* fix: test cases

* fix: correct paginated group roles endpoint and dynamic link generation

- Fixed incorrect  and  link generation in the  endpoint.
  - Ensured  dynamically includes the correct path ().
  - Dynamically constructed  and  links using  and .

- Refactored  function:
  - Simplified conditional logic for  feature flag.
  - Added error handling for invalid page and size parameters.

- Removed hardcoding of URLs in response links to make them adaptive to the environment.

- Improved logging for easier debugging when issues arise.

- Added handling to ensure old behavior (non-dev mode) works as expected.

* chore remove test from here as moving tests in a different PR

* fix: failing tests

Author: Achintya-Chatterjee

controllers/discordactions.js

@@ -119,26 +119,52 @@ const deleteGroupRole = async (req, res) => {
 };
 
 /**
- * Gets all group-roles
+ * Fetches all group roles or provides paginated results when ?dev=true is passed.
  *
- * @param res {Object} - Express response object
+ * @param {Object} req - Express request object.
+ * @param {Object} res - Express response object.
  */
-
-const getAllGroupRoles = async (req, res) => {
+const getPaginatedAllGroupRoles = async (req, res) => {
   try {
-    const { groups } = await discordRolesModel.getAllGroupRoles();
+    const { page = 0, size = 10, dev } = req.query;
+    const limit = parseInt(size, 10) || 10;
+    const offset = parseInt(page, 10) * limit;
+
+    if (limit < 1 || limit > 100) {
+      return res.boom.badRequest("Invalid size. Must be between 1 and 100.");
+    }
+
     const discordId = req.userData?.discordId;
+    if (dev === "true") {
+      const { roles, total } = await discordRolesModel.getPaginatedGroupRolesByPage({ offset, limit });
+      const groupsWithMembershipInfo = await discordRolesModel.enrichGroupDataWithMembershipInfo(discordId, roles);
+
+      const nextPage = offset + limit < total ? parseInt(page, 10) + 1 : null;
+      const prevPage = page > 0 ? parseInt(page, 10) - 1 : null;
+
+      const baseUrl = `${req.baseUrl}${req.path}`;
+      const next = nextPage !== null ? `${baseUrl}?page=${nextPage}&size=${limit}&dev=true` : null;
+      const prev = prevPage !== null ? `${baseUrl}?page=${prevPage}&size=${limit}&dev=true` : null;
+
+      return res.json({
+        message: "Roles fetched successfully!",
+        groups: groupsWithMembershipInfo,
+        links: { next, prev },
+      });
+    }
+
+    const { groups } = await discordRolesModel.getAllGroupRoles();
     const groupsWithMembershipInfo = await discordRolesModel.enrichGroupDataWithMembershipInfo(discordId, groups);
+
     return res.json({
       message: "Roles fetched successfully!",
       groups: groupsWithMembershipInfo,
     });
   } catch (err) {
-    logger.error(`Error while getting roles: ${err}`);
+    logger.error(`Error while fetching paginated group roles: ${err}`);
     return res.boom.badImplementation(INTERNAL_SERVER_ERROR);
   }
 };
-
 const getGroupsRoleId = async (req, res) => {
   try {
     const { discordId } = req.userData;
@@ -534,7 +560,7 @@ const getUserDiscordInvite = async (req, res) => {
 module.exports = {
   getGroupsRoleId,
   createGroupRole,
-  getAllGroupRoles,
+  getPaginatedAllGroupRoles,
   addGroupRoleToMember,
   deleteRole,
   updateDiscordImageForVerification,

middlewares/validators/discordactions.js

@@ -39,9 +39,31 @@ const validateUpdateUsersNicknameStatusBody = async (req, res, next) => {
     res.boom.badRequest(error);
   }
 };
+/**
+ * Middleware: Validates lazy loading parameters in the request.
+ *
+ * @param {Object} req - Express request object.
+ * @param {Object} res - Express response object.
+ * @param {Function} next - Express next middleware function.
+ */
+const validateLazyLoadingParams = async (req, res, next) => {
+  const schema = Joi.object({
+    page: Joi.number().integer().min(0).optional(),
+    size: Joi.number().integer().min(1).max(100).optional(),
+    dev: Joi.string().valid("true").optional(),
+  });
+
+  try {
+    req.query = await schema.validateAsync(req.query);
+    next();
+  } catch (error) {
+    res.boom.badRequest(error.message);
+  }
+};
 
 module.exports = {
   validateGroupRoleBody,
   validateMemberRoleBody,
+  validateLazyLoadingParams,
   validateUpdateUsersNicknameStatusBody,
 };

models/discordactions.js

@@ -102,6 +102,33 @@ const deleteRoleFromDatabase = async (roleId, discordId) => {
   return false;
 };
 
+/**
+ * Fetches paginated group roles by page and size.
+ *
+ * @param {Object} options - Pagination options
+ * @param {number} options.offset - Number of items to skip
+ * @param {number} options.limit - Maximum number of roles to fetch
+ * @returns {Promise<Object>} - Paginated roles and total count
+ */
+const getPaginatedGroupRolesByPage = async ({ offset, limit }) => {
+  try {
+    const snapshot = await discordRoleModel.orderBy("date", "desc").offset(offset).limit(limit).get();
+
+    const roles = snapshot.docs.map((doc) => ({
+      id: doc.id,
+      ...doc.data(),
+    }));
+
+    const totalSnapshot = await discordRoleModel.get();
+    const total = totalSnapshot.size;
+
+    return { roles, total };
+  } catch (err) {
+    logger.error(`Error in getPaginatedGroupRolesByPage: ${err.message}`);
+    throw new Error("Database error while paginating group roles");
+  }
+};
+
 /**
  *
  * @param roleData { Object }: Data of the new role
@@ -1085,6 +1112,7 @@ module.exports = {
   createNewRole,
   removeMemberGroup,
   getGroupRolesForUser,
+  getPaginatedGroupRolesByPage,
   getAllGroupRoles,
   getGroupRoleByName,
   updateGroupRole,

routes/discordactions.js

@@ -3,7 +3,6 @@ const authenticate = require("../middlewares/authenticate");
 const {
   createGroupRole,
   getGroupsRoleId,
-  getAllGroupRoles,
   addGroupRoleToMember,
   deleteRole,
   updateDiscordImageForVerification,
@@ -16,11 +15,13 @@ const {
   syncDiscordGroupRolesInFirestore,
   setRoleToUsersWith31DaysPlusOnboarding,
   deleteGroupRole,
+  getPaginatedAllGroupRoles,
 } = require("../controllers/discordactions");
 const {
   validateGroupRoleBody,
   validateMemberRoleBody,
   validateUpdateUsersNicknameStatusBody,
+  validateLazyLoadingParams,
 } = require("../middlewares/validators/discordactions");
 const checkIsVerifiedDiscord = require("../middlewares/verifydiscord");
 const checkCanGenerateDiscordLink = require("../middlewares/checkCanGenerateDiscordLink");
@@ -33,7 +34,7 @@ const { authorizeAndAuthenticate } = require("../middlewares/authorizeUsersAndSe
 const router = express.Router();
 
 router.post("/groups", authenticate, checkIsVerifiedDiscord, validateGroupRoleBody, createGroupRole);
-router.get("/groups", authenticate, checkIsVerifiedDiscord, getAllGroupRoles);
+router.get("/groups", authenticate, checkIsVerifiedDiscord, validateLazyLoadingParams, getPaginatedAllGroupRoles);
 router.delete("/groups/:groupId", authenticate, checkIsVerifiedDiscord, authorizeRoles([SUPERUSER]), deleteGroupRole);
 router.post("/roles", authenticate, checkIsVerifiedDiscord, validateMemberRoleBody, addGroupRoleToMember);
 router.get("/invite", authenticate, getUserDiscordInvite);