fix case insensitive (#63)

config.go

@@ -149,17 +149,21 @@ func (c *Config) Watch(ctx context.Context) error { //nolint:cyclop,funlen,gocog
 						"provider", provider.watcher,
 					)
 
-					// Find the onChanges should be triggered.
-					oldValues := provider.values
+					// Both oldValues and newValues are merged to empty map to convert to lower case.
+					oldValues := make(map[string]any)
+					maps.Merge(oldValues, provider.values)
+					newValues := make(map[string]any)
+					maps.Merge(newValues, values)
 					provider.values = values
 
+					// Find the onChanges should be triggered.
 					onChanges := func() []func(*Config) {
 						c.onChangesMutex.RLock()
 						defer c.onChangesMutex.RUnlock()
 
 						var callbacks []func(*Config)
 						for path, onChanges := range c.onChanges {
-							if sub(oldValues, path, c.delimiter) != nil || sub(values, path, c.delimiter) != nil {
+							if sub(oldValues, path, c.delimiter) != nil || sub(newValues, path, c.delimiter) != nil {
 								callbacks = append(callbacks, onChanges...)
 							}
 						}

config_test.go

@@ -154,15 +154,15 @@ func TestConfig_Watch(t *testing.T) {
 		var value string
 		assert.NoError(t, config.Unmarshal("config", &value))
 		newValue.Store(value)
-	})
-	watcher.change(map[string]any{"config": "changed"})
+	}, "config")
+	watcher.change(map[string]any{"Config": "changed"})
 	assert.Equal(t, "changed", newValue.Load())
 }
 
 type mapWatcher chan map[string]any
 
 func (m mapWatcher) Load() (map[string]any, error) {
-	return map[string]any{"config": "string"}, nil
+	return map[string]any{"Config": "string"}, nil
 }
 
 func (m mapWatcher) Watch(ctx context.Context, fn func(map[string]any)) error {

internal/maps/merge.go

@@ -14,18 +14,20 @@ func Merge(dst, src map[string]any) {
 		// Ensure key is lower case since the path is case-insensitive.
 		key = strings.ToLower(key)
 
-		// Direct override if the dstVal is not map[string]any.
-		dstMap, succeed := dst[key].(map[string]any)
-		if !succeed {
+		// Direct override if the srcVal is not map[string]any.
+		srcMap, srcOk := srcVal.(map[string]any)
+		if !srcOk {
 			dst[key] = srcVal
 
 			continue
 		}
 
-		// Direct override if the srcVal is not map[string]any.
-		srcMap, succeed := srcVal.(map[string]any)
-		if !succeed {
-			dst[key] = srcVal
+		// Direct override if the dstVal is not map[string]any.
+		dstMap, dstOk := dst[key].(map[string]any)
+		if !dstOk {
+			values := make(map[string]any)
+			Merge(values, srcMap)
+			dst[key] = values
 
 			continue
 		}

internal/maps/merge_test.go

@@ -73,6 +73,12 @@ func TestMerge(t *testing.T) {
 			dst:         map[string]any{"a": 1},
 			expected:    map[string]any{"a": map[string]any{"x": 2}},
 		},
+		{
+			description: "mix case",
+			src:         map[string]any{"a": map[string]any{"X": 2}},
+			dst:         map[string]any{},
+			expected:    map[string]any{"a": map[string]any{"x": 2}},
+		},
 	}
 
 	for _, testcase := range testcases {