accounting: fix panic in core/stats-reset with unknown group - fixes #6327

This also adds tests for the rc commands for stats groups

fs/accounting/stats_groups.go

@@ -2,6 +2,7 @@ package accounting
 
 import (
 	"context"
+	"fmt"
 	"sync"
 
 	"github.com/rclone/rclone/fs/rc"
@@ -190,6 +191,9 @@ func rcResetStats(ctx context.Context, in rc.Params) (rc.Params, error) {
 
 	if group != "" {
 		stats := groups.get(group)
+		if stats == nil {
+			return rc.Params{}, fmt.Errorf("group %q not found", group)
+		}
 		stats.ResetErrors()
 		stats.ResetCounters()
 	} else {

fs/accounting/stats_groups_test.go

@@ -7,8 +7,10 @@ import (
 	"testing"
 	"time"
 
+	"github.com/rclone/rclone/fs/rc"
 	"github.com/rclone/rclone/fstest/testy"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestStatsGroupOperations(t *testing.T) {
@@ -117,6 +119,89 @@ func TestStatsGroupOperations(t *testing.T) {
 			t.Errorf("HeapObjects = %d, expected %d", end.HeapObjects, start.HeapObjects)
 		}
 	})
+
+	testGroupStatsInfo := NewStatsGroup(ctx, "test-group")
+	testGroupStatsInfo.Deletes(1)
+	GlobalStats().Deletes(41)
+
+	t.Run("core/group-list", func(t *testing.T) {
+		call := rc.Calls.Get("core/group-list")
+		require.NotNil(t, call)
+		got, err := call.Fn(ctx, rc.Params{})
+		require.NoError(t, err)
+		require.Equal(t, rc.Params{
+			"groups": []string{
+				"test-group",
+			},
+		}, got)
+	})
+
+	t.Run("core/stats", func(t *testing.T) {
+		call := rc.Calls.Get("core/stats")
+		require.NotNil(t, call)
+		gotNoGroup, err := call.Fn(ctx, rc.Params{})
+		require.NoError(t, err)
+		gotGroup, err := call.Fn(ctx, rc.Params{"group": "test-group"})
+		require.NoError(t, err)
+		assert.Equal(t, int64(42), gotNoGroup["deletes"])
+		assert.Equal(t, int64(1), gotGroup["deletes"])
+	})
+
+	t.Run("core/transferred", func(t *testing.T) {
+		call := rc.Calls.Get("core/transferred")
+		require.NotNil(t, call)
+		gotNoGroup, err := call.Fn(ctx, rc.Params{})
+		require.NoError(t, err)
+		gotGroup, err := call.Fn(ctx, rc.Params{"group": "test-group"})
+		require.NoError(t, err)
+		assert.Equal(t, rc.Params{
+			"transferred": []TransferSnapshot{},
+		}, gotNoGroup)
+		assert.Equal(t, rc.Params{
+			"transferred": []TransferSnapshot{},
+		}, gotGroup)
+	})
+
+	t.Run("core/stats-reset", func(t *testing.T) {
+		call := rc.Calls.Get("core/stats-reset")
+		require.NotNil(t, call)
+
+		assert.Equal(t, int64(41), GlobalStats().deletes)
+		assert.Equal(t, int64(1), testGroupStatsInfo.deletes)
+
+		_, err := call.Fn(ctx, rc.Params{"group": "test-group"})
+		require.NoError(t, err)
+
+		assert.Equal(t, int64(41), GlobalStats().deletes)
+		assert.Equal(t, int64(0), testGroupStatsInfo.deletes)
+
+		_, err = call.Fn(ctx, rc.Params{})
+		require.NoError(t, err)
+
+		assert.Equal(t, int64(0), GlobalStats().deletes)
+		assert.Equal(t, int64(0), testGroupStatsInfo.deletes)
+
+		_, err = call.Fn(ctx, rc.Params{"group": "not-found"})
+		require.ErrorContains(t, err, `group "not-found" not found`)
+
+	})
+
+	testGroupStatsInfo = NewStatsGroup(ctx, "test-group")
+
+	t.Run("core/stats-delete", func(t *testing.T) {
+		call := rc.Calls.Get("core/stats-delete")
+		require.NotNil(t, call)
+
+		assert.Equal(t, []string{"test-group"}, groups.names())
+
+		_, err := call.Fn(ctx, rc.Params{"group": "test-group"})
+		require.NoError(t, err)
+
+		assert.Equal(t, []string{}, groups.names())
+
+		_, err = call.Fn(ctx, rc.Params{"group": "not-found"})
+		require.NoError(t, err)
+	})
 }
 
 func percentDiff(start, end uint64) uint64 {