Cherry pick of a06d506 (#35172) into release-10.11 (#35332)

Automatic Merge

server/channels/app/group.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 
 	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/public/utils"
 	"github.com/mattermost/mattermost/server/v8/channels/store"
 )
 
@@ -25,7 +26,10 @@ func (a *App) GetGroup(id string, opts *model.GetGroupOpts, viewRestrictions *mo
 	}
 
 	if opts != nil && opts.IncludeMemberIDs {
-		users, err := a.Srv().Store().Group().GetMemberUsers(id)
+		perPage := 100
+		users, err := utils.Pager(func(page int) ([]*model.User, error) {
+			return a.Srv().Store().Group().GetMemberUsersPage(id, page, perPage, viewRestrictions)
+		}, perPage)
 		if err != nil {
 			return nil, model.NewAppError("GetGroup", "app.member_count", nil, "", http.StatusInternalServerError).Wrap(err)
 		}

server/channels/app/group_test.go

@@ -12,27 +12,82 @@ import (
 	"github.com/mattermost/mattermost/server/public/model"
 )
 
+// TestGetGroup tests basic group retrieval and verifies that ViewUsersRestrictions
+// are properly applied when fetching member IDs to prevent guest users from
+// enumerating user IDs they shouldn't have access to.
 func TestGetGroup(t *testing.T) {
 	mainHelper.Parallel(t)
-	th := Setup(t)
+	th := Setup(t).InitBasic()
 	defer th.TearDown()
-	group := th.CreateGroup()
 
-	group, err := th.App.GetGroup(group.Id, nil, nil)
+	t.Run("basic retrieval", func(t *testing.T) {
-	require.Nil(t, err)
+		group := th.CreateGroup()
-	require.NotNil(t, group)
 
-	nilGroup, err := th.App.GetGroup(model.NewId(), nil, nil)
+		g, err := th.App.GetGroup(group.Id, nil, nil)
-	require.NotNil(t, err)
+		require.Nil(t, err)
-	require.Nil(t, nilGroup)
+		require.NotNil(t, g)
 
-	group, err = th.App.GetGroup(group.Id, &model.GetGroupOpts{IncludeMemberCount: false}, nil)
+		nilGroup, err := th.App.GetGroup(model.NewId(), nil, nil)
-	require.Nil(t, err)
+		require.NotNil(t, err)
-	require.Nil(t, group.MemberCount)
+		require.Nil(t, nilGroup)
+	})
 
-	group, err = th.App.GetGroup(group.Id, &model.GetGroupOpts{IncludeMemberCount: true}, nil)
+	t.Run("include member count", func(t *testing.T) {
-	require.Nil(t, err)
+		group := th.CreateGroup()
-	require.NotNil(t, group.MemberCount)
+
+		g, err := th.App.GetGroup(group.Id, &model.GetGroupOpts{IncludeMemberCount: false}, nil)
+		require.Nil(t, err)
+		require.Nil(t, g.MemberCount)
+
+		g, err = th.App.GetGroup(group.Id, &model.GetGroupOpts{IncludeMemberCount: true}, nil)
+		require.Nil(t, err)
+		require.NotNil(t, g.MemberCount)
+	})
+
+	t.Run("member IDs respect view restrictions", func(t *testing.T) {
+		user1 := th.CreateUser()
+		user2 := th.CreateUser()
+		user3 := th.CreateUser()
+
+		team := th.CreateTeam()
+		channel := th.CreateChannel(th.Context, team)
+
+		th.LinkUserToTeam(user1, team)
+		th.AddUserToChannel(user1, channel)
+
+		id := model.NewId()
+		groupWithUserIds := &model.GroupWithUserIds{
+			Group: model.Group{
+				DisplayName:    "dn_" + id,
+				Name:           model.NewPointer("name" + id),
+				Source:         model.GroupSourceCustom,
+				AllowReference: true,
+			},
+			UserIds: []string{user1.Id, user2.Id, user3.Id},
+		}
+		group, err := th.App.CreateGroupWithUserIds(groupWithUserIds)
+		require.Nil(t, err)
+
+		opts := &model.GetGroupOpts{IncludeMemberIDs: true}
+
+		g, appErr := th.App.GetGroup(group.Id, opts, nil)
+		require.Nil(t, appErr)
+		assert.Len(t, g.MemberIDs, 3)
+
+		g, appErr = th.App.GetGroup(group.Id, opts, &model.ViewUsersRestrictions{Channels: []string{channel.Id}})
+		require.Nil(t, appErr)
+		assert.Len(t, g.MemberIDs, 1)
+		assert.Contains(t, g.MemberIDs, user1.Id)
+
+		g, appErr = th.App.GetGroup(group.Id, opts, &model.ViewUsersRestrictions{Teams: []string{team.Id}})
+		require.Nil(t, appErr)
+		assert.Len(t, g.MemberIDs, 1)
+		assert.Contains(t, g.MemberIDs, user1.Id)
+
+		g, appErr = th.App.GetGroup(group.Id, opts, &model.ViewUsersRestrictions{Channels: []string{}, Teams: []string{}})
+		require.Nil(t, appErr)
+		assert.Empty(t, g.MemberIDs)
+	})
 }
 
 func TestGetGroupByRemoteID(t *testing.T) {

server/public/utils/page.go

@@ -0,0 +1,43 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package utils
+
+// Pager fetches all items from a paginated API.
+// Pager is a generic function that fetches and aggregates paginated data.
+// It takes a fetch function and a perPage parameter as arguments.
+//
+// The fetch function is responsible for retrieving a slice of items of type T
+// for a given page number. It returns the fetched items and an error, if any.
+// Ideally a developer may want to use a closure to create a fetch function.
+//
+// The perPage parameter specifies the number of items to fetch per page.
+//
+// Example usage:
+//
+//	items, err := Pager(fetchFunc, 10)
+//	if err != nil {
+//	    // handle error
+//	}
+//	// process items
+func Pager[T any](fetch func(page int) ([]T, error), perPage int) ([]T, error) {
+	var list []T
+	var page int
+
+	for {
+		fetched, err := fetch(page)
+		if err != nil {
+			return list, err
+		}
+
+		list = append(list, fetched...)
+
+		if len(fetched) < perPage {
+			break
+		}
+
+		page++
+	}
+
+	return list, nil
+}

server/public/utils/page_test.go

@@ -0,0 +1,69 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package utils
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPager(t *testing.T) {
+	tests := []struct {
+		name      string
+		fetch     func(page int) ([]int, error)
+		perPage   int
+		expected  []int
+		expectErr bool
+	}{
+		{
+			name: "successful fetch",
+			fetch: func(page int) ([]int, error) {
+				if page > 2 {
+					return nil, nil
+				}
+				return []int{page*10 + 1, page*10 + 2, page*10 + 3}, nil
+			},
+			perPage:  3,
+			expected: []int{1, 2, 3, 11, 12, 13, 21, 22, 23},
+		},
+		{
+			name: "fetch with error",
+			fetch: func(page int) ([]int, error) {
+				if page == 1 {
+					return nil, errors.New("fetch error")
+				}
+				return []int{page*10 + 1, page*10 + 2, page*10 + 3}, nil
+			},
+			perPage:   3,
+			expected:  []int{1, 2, 3},
+			expectErr: true,
+		},
+		{
+			name: "fetch with fewer items than perPage",
+			fetch: func(page int) ([]int, error) {
+				if page > 0 {
+					return []int{11, 12}, nil
+				}
+				return []int{page*10 + 1, page*10 + 2, page*10 + 3}, nil
+			},
+			perPage:  3,
+			expected: []int{1, 2, 3, 11, 12},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := Pager(tt.fetch, tt.perPage)
+			if tt.expectErr {
+				assert.Error(t, err)
+				assert.Equal(t, tt.expected, result)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.expected, result)
+			}
+		})
+	}
+}