Add support for raw map[string]any type to riverjson encoding.

CHANGELOG.md

@@ -7,6 +7,10 @@ internal API changes are not present.
 Main (unreleased)
 -----------------
 
+### Features
+
+- Add support for raw map[string]any type to riverjson encoding. (@wildum)
+
 v0.3.0 (2023-10-26)
 -------------------
 

encoding/riverjson/riverjson.go

@@ -17,7 +17,7 @@ import (
 var goRiverDefaulter = reflect.TypeOf((*value.Defaulter)(nil)).Elem()
 
 // MarshalBody marshals the provided Go value to a JSON representation of
-// River. MarshalBody panics if not given a struct with River tags.
+// River. MarshalBody panics if not given a struct with River tags or a map[string]any.
 func MarshalBody(val interface{}) ([]byte, error) {
 	rv := reflect.ValueOf(val)
 	return json.Marshal(encodeStructAsBody(rv))
@@ -33,30 +33,50 @@ func encodeStructAsBody(rv reflect.Value) jsonBody {
 
 	if rv.Kind() == reflect.Invalid {
 		return []jsonStatement{}
-	} else if rv.Kind() != reflect.Struct {
-		panic(fmt.Sprintf("river/encoding/riverjson: can only encode struct values to bodies, got %s", rv.Kind()))
-	}
-
-	fields := rivertags.Get(rv.Type())
-	defaults := reflect.New(rv.Type()).Elem()
-	if defaults.CanAddr() && defaults.Addr().Type().Implements(goRiverDefaulter) {
-		defaults.Addr().Interface().(value.Defaulter).SetToDefault()
 	}
 
 	body := []jsonStatement{}
 
-	for _, field := range fields {
-		fieldVal := reflectutil.Get(rv, field)
-		fieldValDefault := reflectutil.Get(defaults, field)
+	switch rv.Kind() {
+	case reflect.Struct:
+		fields := rivertags.Get(rv.Type())
+		defaults := reflect.New(rv.Type()).Elem()
+		if defaults.CanAddr() && defaults.Addr().Type().Implements(goRiverDefaulter) {
+			defaults.Addr().Interface().(value.Defaulter).SetToDefault()
+		}
 
-		var isEqual = fieldVal.Comparable() && fieldVal.Equal(fieldValDefault)
-		var isZero = fieldValDefault.IsZero() && fieldVal.IsZero()
+		for _, field := range fields {
+			fieldVal := reflectutil.Get(rv, field)
+			fieldValDefault := reflectutil.Get(defaults, field)
 
-		if field.IsOptional() && (isEqual || isZero) {
-			continue
+			isEqual := fieldVal.Comparable() && fieldVal.Equal(fieldValDefault)
+			isZero := fieldValDefault.IsZero() && fieldVal.IsZero()
+
+			if field.IsOptional() && (isEqual || isZero) {
+				continue
+			}
+
+			body = append(body, encodeFieldAsStatements(nil, field, fieldVal)...)
 		}
 
-		body = append(body, encodeFieldAsStatements(nil, field, fieldVal)...)
+	case reflect.Map:
+		if rv.Type().Key().Kind() != reflect.String {
+			panic("river/encoding/riverjson: unsupported map type; expected map[string]T, got " + rv.Type().String())
+		}
+
+		iter := rv.MapRange()
+		for iter.Next() {
+			mapKey, mapValue := iter.Key(), iter.Value()
+
+			body = append(body, jsonAttr{
+				Name:  mapKey.String(),
+				Type:  "attr",
+				Value: buildJSONValue(value.FromRaw(mapValue)),
+			})
+		}
+
+	default:
+		panic(fmt.Sprintf("river/encoding/riverjson: can only encode struct or map values to bodies, got %s", rv.Kind()))
 	}
 
 	return body

encoding/riverjson/riverjson_test.go

@@ -333,3 +333,22 @@ func TestMapBlocks(t *testing.T) {
 	require.NoError(t, err)
 	require.JSONEq(t, expect, string(bb))
 }
+
+func TestRawMap(t *testing.T) {
+	val := map[string]any{"field": "value", "anotherField": 3}
+
+	expect := `[{
+		"name": "field",
+		"type": "attr",
+		"value": { "type": "string", "value": "value" }
+	},
+	{
+		"name": "anotherField",
+		"type": "attr",
+		"value": { "type": "number", "value": 3 }
+	}]`
+
+	bb, err := riverjson.MarshalBody(val)
+	require.NoError(t, err)
+	require.JSONEq(t, expect, string(bb))
+}