func sortMergeListsByNameMap(s map[string]interface{}, t reflect.Type) (map[string]interface{}, error) {
newS := map[string]interface{}{}
for k, v := range s {
fieldType, fieldPatchStrategy, fieldPatchMergeKey, err := forkedjson.LookupPatchMetadata(t, k)
if err != nil {
return nil, err
}
// If v is a map or a merge slice, recurse.
if typedV, ok := v.(map[string]interface{}); ok {
var err error
v, err = sortMergeListsByNameMap(typedV, fieldType)
if err != nil {
return nil, err
}
} else if typedV, ok := v.([]interface{}); ok {
if fieldPatchStrategy == "merge" {
var err error
v, err = sortMergeListsByNameArray(typedV, fieldType.Elem(), fieldPatchMergeKey)
if err != nil {
return nil, err
}
}
}
newS[k] = v
}
return newS, nil
}
// Merge fields from a patch map into the original map. Note: This may modify
// both the original map and the patch because getting a deep copy of a map in
// golang is highly non-trivial.
func mergeMap(original, patch map[string]interface{}, t reflect.Type) (map[string]interface{}, error) {
// If the map contains "$patch: replace", don't merge it, just use the
// patch map directly. Later on, can add a non-recursive replace that only
// affects the map that the $patch is in.
if v, ok := patch[specialKey]; ok {
if v == "replace" {
delete(patch, specialKey)
return patch, nil
}
return nil, fmt.Errorf("unknown patch type found: %s", v)
}
// nil is an accepted value for original to simplify logic in other places.
// If original is nil, create a map so if patch requires us to modify the
// map, it'll work.
if original == nil {
original = map[string]interface{}{}
}
// Start merging the patch into the original.
for k, patchV := range patch {
// If the value of this key is null, delete the key if it exists in the
// original. Otherwise, skip it.
if patchV == nil {
if _, ok := original[k]; ok {
delete(original, k)
}
continue
}
_, ok := original[k]
if !ok {
// If it's not in the original document, just take the patch value.
original[k] = patchV
continue
}
// If the data type is a pointer, resolve the element.
if t.Kind() == reflect.Ptr {
t = t.Elem()
}
// If they're both maps or lists, recurse into the value.
// First find the fieldPatchStrategy and fieldPatchMergeKey.
fieldType, fieldPatchStrategy, fieldPatchMergeKey, err := forkedjson.LookupPatchMetadata(t, k)
if err != nil {
return nil, err
}
originalType := reflect.TypeOf(original[k])
patchType := reflect.TypeOf(patchV)
if originalType == patchType {
if originalType.Kind() == reflect.Map && fieldPatchStrategy != "replace" {
typedOriginal := original[k].(map[string]interface{})
typedPatch := patchV.(map[string]interface{})
var err error
original[k], err = mergeMap(typedOriginal, typedPatch, fieldType)
if err != nil {
return nil, err
}
continue
}
if originalType.Kind() == reflect.Slice && fieldPatchStrategy == "merge" {
elemType := fieldType.Elem()
typedOriginal := original[k].([]interface{})
typedPatch := patchV.([]interface{})
var err error
original[k], err = mergeSlice(typedOriginal, typedPatch, elemType, fieldPatchMergeKey)
if err != nil {
return nil, err
}
continue
}
}
// If originalType and patchType are different OR the types are both
// maps or slices but we're just supposed to replace them, just take
// the value from patch.
original[k] = patchV
}
return original, nil
}