Merge pull request #1 from Pexeso/usenumber

Add setting for unmarshalling JSON with UseNumber

Author: stetra

orderedmap.go

@@ -46,6 +46,7 @@ type OrderedMap struct {
 	keys       []string
 	values     map[string]interface{}
 	escapeHTML bool
+	useNumber bool
 }
 
 func New() *OrderedMap {
@@ -60,6 +61,10 @@ func (o *OrderedMap) SetEscapeHTML(on bool) {
 	o.escapeHTML = on
 }
 
+func (o *OrderedMap) SetUseNumber(on bool) {
+	o.useNumber = on
+}
+
 func (o *OrderedMap) Get(key string) (interface{}, bool) {
 	val, exists := o.values[key]
 	return val, exists
@@ -125,13 +130,34 @@ func (o *OrderedMap) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
+func unmarshalJSONUseNumber(s string, v interface{}) error {
+	r := strings.NewReader(s)
+	decoder := json.NewDecoder(r)
+	decoder.UseNumber()
+	err := decoder.Decode(v)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func mapStringToOrderedMap(s string, o *OrderedMap) error {
 	// parse string into map
 	m := map[string]interface{}{}
-	err := json.Unmarshal([]byte(s), &m)
-	if err != nil {
-		return err
+
+	if o.useNumber {
+		err := unmarshalJSONUseNumber(s, &m)
+		if err != nil {
+			return err
+		}
+	} else {
+		err := json.Unmarshal([]byte(s), &m)
+		if err != nil {
+			return err
+		}
 	}
+
 	// Get the order of the keys
 	orderedKeys := []KeyIndex{}
 	for k, _ := range m {
@@ -194,6 +220,7 @@ func mapStringToOrderedMap(s string, o *OrderedMap) error {
 					// this may be recursive it values in the map are also maps
 					if hasValidJson {
 						newMap := New()
+						newMap.SetUseNumber(o.useNumber) // Preserve number setting
 						err := mapStringToOrderedMap(valueStr, newMap)
 						if err != nil {
 							return err

orderedmap_test.go

@@ -400,6 +400,50 @@ func TestUnmarshalJSONStruct(t *testing.T) {
 	}
 }
 
+func TestRemarshalJSONWithoutUseNumber(t *testing.T) {
+	// 9007199254740993 is the smallest integer which cannot be represented exactly as a float64
+	const input = `{"data":{"x":9007199254740993}}`
+	const expected = `{"data":{"x":9007199254740992}}`
+
+	o := New()
+	o.SetUseNumber(false)
+
+	err := json.Unmarshal([]byte(input), &o)
+	if err != nil {
+		t.Fatalf("JSON unmarshal error: %v", err)
+	}
+
+	marshalled, err := json.Marshal(o)
+	if err != nil {
+		t.Errorf("Marshal failed: %v", err)
+	}
+
+	if string(marshalled) != expected {
+		t.Errorf("unexpected value: %s instead of %s", marshalled, expected)
+	}
+}
+
+func TestRemarshalJSONUseNumber(t *testing.T) {
+	const input = `{"data":{"x":9007199254740993}}`
+
+	o := New()
+	o.SetUseNumber(true)
+
+	err := json.Unmarshal([]byte(input), &o)
+	if err != nil {
+		t.Fatalf("JSON unmarshal error: %v", err)
+	}
+
+	marshalled, err := json.Marshal(o)
+	if err != nil {
+		t.Errorf("Marshal failed: %v", err)
+	}
+
+	if string(marshalled) != input {
+		t.Errorf("unexpected value: %s instead of %s", marshalled, input)
+	}
+}
+
 func TestOrderedMap_SortKeys(t *testing.T) {
 	s := `
 {