[Improve] renders study list and Fixed eslint error

.eslintrc.js

@@ -27,6 +27,7 @@ module.exports = {
   plugins: [
     'react',
   ],
+  ignorePatterns: ['build/', 'node_modules/'],
   rules: {
     indent: ['error', 2],
     'no-trailing-spaces': 'error',

src/reducers/slice.js

@@ -50,16 +50,10 @@ const { actions, reducer } = createSlice({
   },
 
   reducers: {
-    setStudyGroups(state, { payload: { groups, tag } }) {
+    setStudyGroups(state, { payload: groups }) {
       return {
         ...state,
-        groups: tag ? groups.reduce((studies, group) => {
-          if (group.tags.includes(tag)) {
-            return [...studies, group];
-          }
-
-          return studies;
-        }, []) : groups,
+        groups,
       };
     },
 
@@ -167,9 +161,9 @@ export const {
 } = actions;
 
 export const loadStudyGroups = (tag) => async (dispatch) => {
-  const groups = await getStudyGroups();
+  const groups = await getStudyGroups(tag);
 
-  dispatch(setStudyGroups({ groups, tag }));
+  dispatch(setStudyGroups(groups));
 };
 
 export const loadStudyGroup = (id) => async (dispatch) => {

src/reducers/slice.test.js

@@ -72,34 +72,17 @@ describe('reducer', () => {
   });
 
   describe('setStudyGroups', () => {
-    context('with tag', () => {
-      it('get study groups list with tags filtered', () => {
-        const initialState = {
-          groups: [],
-        };
-
-        const state = reducer(
-          initialState,
-          setStudyGroups({ groups: STUDY_GROUPS, tag: 'JavaScript' }),
-        );
-
-        expect(state.groups).toHaveLength(1);
-      });
-    });
-
-    context('without tag', () => {
-      it("get study groups list doesn't tags filtered", () => {
-        const initialState = {
-          groups: [],
-        };
+    it('get study groups list', () => {
+      const initialState = {
+        groups: [],
+      };
 
-        const state = reducer(
-          initialState,
-          setStudyGroups({ groups: STUDY_GROUPS, tag: '' }),
-        );
+      const state = reducer(
+        initialState,
+        setStudyGroups(STUDY_GROUPS),
+      );
 
-        expect(state.groups).toHaveLength(2);
-      });
+      expect(state.groups).toHaveLength(2);
     });
   });
 
@@ -315,10 +298,7 @@ describe('async actions', () => {
 
       const actions = store.getActions();
 
-      expect(actions[0]).toEqual(setStudyGroups({
-        groups: [],
-        tag: undefined,
-      }));
+      expect(actions[0]).toEqual(setStudyGroups([]));
     });
   });
 

src/services/api.js

@@ -1,7 +1,15 @@
 import { db, auth } from './firebase';
 
-export const getStudyGroups = async () => {
-  const response = await db.collection('groups').get();
+const branchGetGroups = (tag) => {
+  if (tag) {
+    return db.collection('groups').where('tags', 'array-contains', tag).get();
+  }
+
+  return db.collection('groups').get();
+};
+
+export const getStudyGroups = async (tag) => {
+  const response = await branchGetGroups(tag);
 
   const groups = response.docs.map((doc) => ({
     ...doc.data(),