Fix for map[interface{}]interface{} to JSON conversion (#87)

conversions.go

@@ -5,6 +5,7 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"net/url"
 	"strconv"
 )
@@ -47,13 +48,74 @@ func SetURLValuesSliceKeySuffix(s string) error {
 // JSON converts the contained object to a JSON string
 // representation
 func (m Map) JSON() (string, error) {
+	for k, v := range m {
+		m[k] = cleanUp(v)
+	}
+
 	result, err := json.Marshal(m)
 	if err != nil {
 		err = errors.New("objx: JSON encode failed with: " + err.Error())
 	}
 	return string(result), err
 }
 
+func cleanUpInterfaceArray(in []interface{}) []interface{} {
+	result := make([]interface{}, len(in))
+	for i, v := range in {
+		result[i] = cleanUp(v)
+	}
+	return result
+}
+
+func cleanUpInterfaceMap(in map[interface{}]interface{}) Map {
+	result := Map{}
+	for k, v := range in {
+		result[fmt.Sprintf("%v", k)] = cleanUp(v)
+	}
+	return result
+}
+
+func cleanUpStringMap(in map[string]interface{}) Map {
+	result := Map{}
+	for k, v := range in {
+		result[k] = cleanUp(v)
+	}
+	return result
+}
+
+func cleanUpMSIArray(in []map[string]interface{}) []Map {
+	result := make([]Map, len(in))
+	for i, v := range in {
+		result[i] = cleanUpStringMap(v)
+	}
+	return result
+}
+
+func cleanUpMapArray(in []Map) []Map {
+	result := make([]Map, len(in))
+	for i, v := range in {
+		result[i] = cleanUpStringMap(v)
+	}
+	return result
+}
+
+func cleanUp(v interface{}) interface{} {
+	switch v := v.(type) {
+	case []interface{}:
+		return cleanUpInterfaceArray(v)
+	case []map[string]interface{}:
+		return cleanUpMSIArray(v)
+	case map[interface{}]interface{}:
+		return cleanUpInterfaceMap(v)
+	case Map:
+		return cleanUpStringMap(v)
+	case []Map:
+		return cleanUpMapArray(v)
+	default:
+		return v
+	}
+}
+
 // MustJSON converts the contained object to a JSON string
 // representation and panics if there is an error
 func (m Map) MustJSON() string {

conversions_test.go

@@ -18,6 +18,20 @@ func TestConversionJSON(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, jsonString, result)
 	assert.Equal(t, jsonString, o.MustJSON())
+
+	i := objx.Map{
+		"a": map[interface{}]interface{}{"b": objx.Map{"c": map[interface{}]interface{}{"d": "e"}},
+			"f": []objx.Map{{"g": map[interface{}]interface{}{"h": "i"}}},
+			"j": []map[string]interface{}{{"k": map[interface{}]interface{}{"l": "m"}}},
+			"n": []interface{}{objx.Map{"o": "p"}},
+		},
+	}
+
+	jsonString = `{"a":{"b":{"c":{"d":"e"}},"f":[{"g":{"h":"i"}}],"j":[{"k":{"l":"m"}}],"n":[{"o":"p"}]}}`
+	result, err = i.JSON()
+	require.NoError(t, err)
+	assert.Equal(t, jsonString, result)
+	assert.Equal(t, jsonString, i.MustJSON())
 }
 
 func TestConversionJSONWithError(t *testing.T) {