Merge pull request #23 from iawia002/maps

maps: add a helper function to set the value of a nested field for the map

maps/maps.go

@@ -0,0 +1,30 @@
+package maps
+
+import (
+	"strings"
+)
+
+// SetNestedField sets the value of a nested field (eg: a.b.c) for the source map.
+//
+// eg:
+//
+//	src := make(map[string]interface{})
+//	SetNestedField(src, "a.b", 1)
+//
+// src: map[a:map[b:1]]
+func SetNestedField(src map[string]interface{}, key string, value interface{}) {
+	setValueRecursively(src, strings.Split(key, "."), value)
+}
+
+func setValueRecursively(src map[string]interface{}, keys []string, value interface{}) {
+	if len(keys) == 1 {
+		src[keys[0]] = value
+		return
+	}
+
+	currentKey := keys[0]
+	if _, ok := src[currentKey].(map[string]interface{}); !ok {
+		src[currentKey] = make(map[string]interface{})
+	}
+	setValueRecursively(src[currentKey].(map[string]interface{}), keys[1:], value)
+}

maps/maps_test.go

@@ -0,0 +1,69 @@
+package maps
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestSetNestedField(t *testing.T) {
+	tests := []struct {
+		name   string
+		src    map[string]interface{}
+		key    string
+		value  interface{}
+		wanted map[string]interface{}
+	}{
+		{
+			name: "normal test",
+			src: map[string]interface{}{
+				"aa": 1,
+			},
+			key:   "bb.cc",
+			value: 1,
+			wanted: map[string]interface{}{
+				"aa": 1,
+				"bb": map[string]interface{}{
+					"cc": 1,
+				},
+			},
+		},
+		{
+			name: "normal test 2",
+			src: map[string]interface{}{
+				"aa": 1,
+				"bb": map[string]interface{}{},
+			},
+			key:   "bb.cc",
+			value: 1,
+			wanted: map[string]interface{}{
+				"aa": 1,
+				"bb": map[string]interface{}{
+					"cc": 1,
+				},
+			},
+		},
+		{
+			name: "override test",
+			src: map[string]interface{}{
+				"aa": 1,
+				"bb": 1,
+			},
+			key:   "bb.cc",
+			value: 1,
+			wanted: map[string]interface{}{
+				"aa": 1,
+				"bb": map[string]interface{}{
+					"cc": 1,
+				},
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			SetNestedField(tt.src, tt.key, tt.value)
+			if !reflect.DeepEqual(tt.src, tt.wanted) {
+				t.Errorf("SetNestedField() = %v, want %v", tt.src, tt.wanted)
+			}
+		})
+	}
+}