terraform/helper/hilmapstructure/hilmapstructure.go

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package hilmapstructure
import (
"fmt"
"reflect"
"github.com/mitchellh/mapstructure"
)
var hilMapstructureDecodeHookEmptySlice []interface{}
var hilMapstructureDecodeHookStringSlice []string
var hilMapstructureDecodeHookEmptyMap map[string]interface{}
// WeakDecode behaves in the same way as mapstructure.WeakDecode but has a
// DecodeHook which defeats the backward compatibility mode of mapstructure
// which WeakDecodes []interface{}{} into an empty map[string]interface{}. This
// allows us to use WeakDecode (desirable), but not fail on empty lists.
func WeakDecode(m interface{}, rawVal interface{}) error {
config := &mapstructure.DecoderConfig{
DecodeHook: func(source reflect.Type, target reflect.Type, val interface{}) (interface{}, error) {
sliceType := reflect.TypeOf(hilMapstructureDecodeHookEmptySlice)
stringSliceType := reflect.TypeOf(hilMapstructureDecodeHookStringSlice)
mapType := reflect.TypeOf(hilMapstructureDecodeHookEmptyMap)
if (source == sliceType || source == stringSliceType) && target == mapType {
return nil, fmt.Errorf("Cannot convert a []interface{} into a map[string]interface{}")
}
return val, nil
},
WeaklyTypedInput: true,
Result: rawVal,
}
decoder, err := mapstructure.NewDecoder(config)
if err != nil {
return err
}
return decoder.Decode(m)
}