WIP

internal/handlers/handler_test.go

@@ -580,15 +580,14 @@ func TestReadOnlyHandlers(t *testing.T) {
 			compareFunc: func(t testing.TB, expected, actual any) {
 				expectedDoc, actualDoc := expected.(types.Document), actual.(types.Document)
 
-				testutil.CompareByPath(t, expectedDoc, actualDoc, 1_000_000, "totalSize")
-				testutil.CompareByPath(t, expectedDoc, actualDoc, 1, "totalSizeMb")
+				testutil.CompareAndSetByPath(t, expectedDoc, actualDoc, 1_000_000, "totalSize")
+				testutil.CompareAndSetByPath(t, expectedDoc, actualDoc, 1, "totalSizeMb")
 
 				expectedDBs := testutil.GetByPath(t, expectedDoc, "databases").(types.Array)
 				actualDBs := testutil.GetByPath(t, actualDoc, "databases").(types.Array)
 				require.Equal(t, len(expectedDBs), len(actualDBs))
 				for i, actualDB := range actualDBs {
-					expectedDB := expectedDBs[i]
-					testutil.CompareByPath(t, expectedDB, actualDB, 200_000, "sizeOnDisk")
+					testutil.CompareAndSetByPath(t, expectedDBs[i], actualDB, 200_000, "sizeOnDisk")
 				}
 
 				assert.Equal(t, expectedDoc, actualDoc)

internal/types/array.go

@@ -19,7 +19,7 @@ import "fmt"
 // Array represents BSON array.
 type Array []any
 
-// Get returns the value at the given index.
+// Get returns a value at the given index.
 func (a Array) Get(index int) (any, error) {
 	if l := len(a); index < 0 || index >= l {
 		return nil, fmt.Errorf("types.Array.Get: index %d is out of bounds [0-%d)", index, l)
@@ -28,7 +28,7 @@ func (a Array) Get(index int) (any, error) {
 	return a[index], nil
 }
 
-// GetByPath returns Array or Object value by path - a sequence of indexes and keys.
+// GetByPath returns a value by path - a sequence of indexes and keys.
 func (a Array) GetByPath(path ...string) (any, error) {
 	return getByPath(a, path...)
 }

internal/types/document.go

@@ -181,7 +181,7 @@ func (d *Document) add(key string, value any) error {
 	return nil
 }
 
-// Get returns the value at the given key.
+// Get returns a value at the given key.
 func (d Document) Get(key string) (any, error) {
 	if value, ok := d.m[key]; ok {
 		return value, nil
@@ -190,7 +190,7 @@ func (d Document) Get(key string) (any, error) {
 	return nil, fmt.Errorf("types.Document.Get: key not found: %q", key)
 }
 
-// GetByPath returns Array or Object value by path - a sequence of indexes and keys.
+// GetByPath returns a value by path - a sequence of indexes and keys.
 func (d Document) GetByPath(path ...string) (any, error) {
 	return getByPath(d, path...)
 }

internal/types/path.go

@@ -19,7 +19,7 @@ import (
 	"strconv"
 )
 
-// getByPath returns Array or Object value by path - a sequence of indexes and keys.
+// getByPath returns a value by path - a sequence of indexes and keys.
 func getByPath(str any, path ...string) (any, error) {
 	for _, p := range path {
 		switch s := str.(type) {

internal/util/testutil/path.go

@@ -25,6 +25,7 @@ import (
 	"github.com/FerretDB/FerretDB/internal/types"
 )
 
+// GetByPath returns a value by path - a sequence of indexes and keys.
 func GetByPath(tb testing.TB, str any, path ...string) any {
 	tb.Helper()
 
@@ -43,6 +44,9 @@ func GetByPath(tb testing.TB, str any, path ...string) any {
 	return res
 }
 
+// SetByPath sets the value by path - a sequence of indexes and keys.
+//
+// The path must exist.
 func SetByPath(tb testing.TB, str any, value any, path ...string) {
 	tb.Helper()
 
@@ -56,29 +60,33 @@ func SetByPath(tb testing.TB, str any, value any, path ...string) {
 			index, err := strconv.Atoi(p)
 			require.NoError(tb, err)
 
-			if !last {
-				str, err = s.Get(index)
-			} else {
+			str, err = s.Get(index)
+			require.NoError(tb, err)
+
+			if last {
 				err = s.Set(index, value)
+				require.NoError(tb, err)
 			}
-			require.NoError(tb, err)
 
 		case types.Document:
 			var err error
-			if !last {
-				str, err = s.Get(p)
-			} else {
+			str, err = s.Get(p)
+			require.NoError(tb, err)
+
+			if last {
 				err = s.Set(p, value)
+				require.NoError(tb, err)
 			}
-			require.NoError(tb, err)
 
 		default:
 			tb.Fatalf("can't access %T by path %q", str, p)
 		}
 	}
 }
 
-func CompareByPath(tb testing.TB, expected, actual any, delta float64, path ...string) {
+// CompareAndSetByPath asserts that two values with the same path in two objects (documents or arrays)
+// are within a given delta, then updates the expected object with the actual value.
+func CompareAndSetByPath(tb testing.TB, expected, actual any, delta float64, path ...string) {
 	tb.Helper()
 
 	expectedV := GetByPath(tb, expected, path...)