[MM-60603] Don't follow threads when marking them as read on focus (#28263)

* [MM-60603] Don't follow threads when marking them as read on focus

* Fix tests

* Fix lint

* Fix the original bug in the API call

server/channels/app/user.go

@@ -2831,13 +2831,10 @@ func (a *App) UpdateThreadReadForUser(c request.CTX, currentSessionId, userID, t
 		return nil, err
 	}
 
-	opts := store.ThreadMembershipOpts{
-		Following:       true,
-		UpdateFollowing: true,
-	}
-	membership, storeErr := a.Srv().Store().Thread().MaintainMembership(userID, threadID, opts)
-	if storeErr != nil {
-		return nil, model.NewAppError("UpdateThreadReadForUser", "app.user.update_thread_read_for_user.app_error", nil, "", http.StatusInternalServerError).Wrap(storeErr)
+	// If the thread doesn't have a membership, we shouldn't try to mark it as unread
+	membership, err := a.GetThreadMembershipForUser(userID, threadID)
+	if err != nil {
+		return nil, err
 	}
 
 	previousUnreadMentions := membership.UnreadMentions

server/channels/app/user_test.go

@@ -8,7 +8,6 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
-	"net/http"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -1930,7 +1929,7 @@ func TestPatchUser(t *testing.T) {
 }
 
 func TestUpdateThreadReadForUser(t *testing.T) {
-	t.Run("Ensure thread membership is created and followed", func(t *testing.T) {
+	t.Run("Ensure thread membership exists before updating read", func(t *testing.T) {
 		th := Setup(t).InitBasic()
 		defer th.TearDown()
 		th.App.UpdateConfig(func(cfg *model.Config) {
@@ -1947,48 +1946,13 @@ func TestUpdateThreadReadForUser(t *testing.T) {
 		require.Zero(t, threads.Total)
 
 		_, appErr = th.App.UpdateThreadReadForUser(th.Context, "currentSessionId", th.BasicUser.Id, th.BasicChannel.TeamId, rootPost.Id, replyPost.CreateAt)
-		require.Nil(t, appErr)
-
-		threads, appErr = th.App.GetThreadsForUser(th.BasicUser.Id, th.BasicTeam.Id, model.GetUserThreadsOpts{})
-		require.Nil(t, appErr)
-		assert.NotZero(t, threads.Total)
-
-		threadMembership, appErr := th.App.GetThreadMembershipForUser(th.BasicUser.Id, rootPost.Id)
-		require.Nil(t, appErr)
-		require.NotNil(t, threadMembership)
-		assert.True(t, threadMembership.Following)
-
-		_, appErr = th.App.GetThreadMembershipForUser(th.BasicUser.Id, "notfound")
 		require.NotNil(t, appErr)
-		assert.Equal(t, http.StatusNotFound, appErr.StatusCode)
-	})
 
-	t.Run("Ensure no panic on error", func(t *testing.T) {
-		th := SetupWithStoreMock(t)
-		defer th.TearDown()
-
-		mockStore := th.App.Srv().Store().(*storemocks.Store)
-		mockUserStore := storemocks.UserStore{}
-		mockUserStore.On("Count", mock.Anything).Return(int64(10), nil)
-		mockUserStore.On("Get", mock.Anything, "user1").Return(&model.User{Id: "user1"}, nil)
-
-		mockThreadStore := storemocks.ThreadStore{}
-		mockThreadStore.On("MaintainMembership", "user1", "postid", mock.Anything).Return(nil, errors.New("error"))
-
-		var err error
-		th.App.ch.srv.userService, err = users.New(users.ServiceConfig{
-			UserStore:    &mockUserStore,
-			SessionStore: &storemocks.SessionStore{},
-			OAuthStore:   &storemocks.OAuthStore{},
-			ConfigFn:     th.App.ch.srv.platform.Config,
-			LicenseFn:    th.App.ch.srv.License,
-		})
+		_, err := th.App.Srv().Store().Thread().MaintainMembership(th.BasicUser.Id, rootPost.Id, store.ThreadMembershipOpts{Following: true, UpdateFollowing: true})
 		require.NoError(t, err)
-		mockStore.On("User").Return(&mockUserStore)
-		mockStore.On("Thread").Return(&mockThreadStore)
 
-		_, err = th.App.UpdateThreadReadForUser(th.Context, "currentSessionId", "user1", "team1", "postid", 100)
-		require.Error(t, err)
+		_, appErr = th.App.UpdateThreadReadForUser(th.Context, "currentSessionId", th.BasicUser.Id, th.BasicChannel.TeamId, rootPost.Id, replyPost.CreateAt)
+		require.Nil(t, appErr)
 	})
 }