fix(datastore): allow non-empty values in the slice

datastore/datastore.go

@@ -682,7 +682,7 @@ func putMutations(keys []*Key, src interface{}) ([]*pb.Mutation, error) {
  v := reflect.ValueOf(src)
  var multiArgType multiArgType
 
- // If kind is of type slice, return error
+ // If kind is not of type slice, return error
  if kind := v.Kind(); kind != reflect.Slice {
  return nil, fmt.Errorf("%w: dst: expected slice got %v", ErrInvalidEntityType, kind.String())
  }

datastore/save.go

@@ -288,11 +288,17 @@ func saveSliceProperty(props *[]Property, name string, opts saveOpts, v reflect.
  return err
  }
  for _, p := range elemProps {
- v, ok := values[p.Name]
- if !ok {
- return fmt.Errorf("datastore: unexpected property %q in elem %d of slice", p.Name, i)
+ if len(values) != 0 {
+ v, ok := values[p.Name]
+ if !ok {
+ return fmt.Errorf("datastore: unexpected property %q in elem %d of slice", p.Name, i)
+ }
+ values[p.Name] = append(v, p.Value)
+ } else {
+ // This is the first non-empty element
+ values[p.Name] = []interface{}{p.Value}
+ headProps = elemProps
  }
- values[p.Name] = append(v, p.Value)
  }
  }
 

datastore/util_test.go

@@ -689,6 +689,25 @@ var testCases = []testCase{
  "",
  "",
  },
+ {
+ "omit empty, fields populated, 1st, 2nd and 4th elements in slice are empty",
+ &Omit{
+ A: "a",
+ B: 10,
+ C: true,
+ F: []int{0, 0, 11, 0, 12, 0},
+ S: S{St: "string"},
+ },
+ &PropertyList{
+ Property{Name: "A", Value: "a", NoIndex: false},
+ Property{Name: "Bb", Value: int64(10), NoIndex: false},
+ Property{Name: "C", Value: true, NoIndex: true},
+ Property{Name: "F", Value: []interface{}{int64(11), int64(12)}, NoIndex: false},
+ Property{Name: "St", Value: "string", NoIndex: false},
+ },
+ "",
+ "",
+ },
  {
  "omit empty does not propagate",
  &NoOmits{