fix: merge custom block locale messages

src/composer.ts

@@ -80,7 +80,8 @@ import {
   isRegExp,
   isBoolean,
   isPlainObject,
-  makeSymbol
+  makeSymbol,
+  isObject
 } from './utils'
 
 // extend VNode interface
@@ -269,7 +270,7 @@ function getLocaleMessages<
   const { messages, __i18n } = options
 
   // prettier-ignore
-  let ret = isPlainObject(messages)
+  const ret = isPlainObject(messages)
     ? messages
     : isArray(__i18n)
       ? {}
@@ -278,7 +279,7 @@ function getLocaleMessages<
   // merge locale messages of i18n custom block
   if (isArray(__i18n)) {
     __i18n.forEach(raw => {
-      ret = Object.assign(ret, isString(raw) ? JSON.parse(raw) : raw)
+      deepCopy(isString(raw) ? JSON.parse(raw) : raw, ret)
     })
     return ret
   }
@@ -291,6 +292,27 @@ function getLocaleMessages<
   return ret
 }
 
+const hasOwnProperty = Object.prototype.hasOwnProperty
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function hasOwn(obj: object | Array<any>, key: string): boolean {
+  return hasOwnProperty.call(obj, key)
+}
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function deepCopy(source: any, destination: any): void {
+  for (const key in source) {
+    if (hasOwn(source, key)) {
+      if (!isObject(source[key])) {
+        destination[key] = destination[key] != null ? destination[key] : {}
+        destination[key] = source[key]
+      } else {
+        destination[key] = destination[key] != null ? destination[key] : {}
+        deepCopy(source[key], destination[key])
+      }
+    }
+  }
+}
+
 export function addPreCompileMessages<Message = VueMessageType>(
   messages: LocaleMessages<Message>,
   functions: MessageFunctions<Message>

test/composer.test.ts

@@ -972,6 +972,61 @@ describe('__i18n', () => {
       }
     })
   })
+
+  test('merge locale messages', () => {
+    const msgFn = () => 'ふー'
+    const options = {
+      __i18n: [
+        JSON.stringify({ en: { hello: 'Hello,world!' } }),
+        JSON.stringify({ ja: { hello: 'こんにちは、世界！' } })
+      ],
+      messages: {
+        en: { foo: 'foo' },
+        ja: { foo: msgFn }
+      }
+    }
+    const { messages } = createComposer(
+      options as ComposerOptions<VueMessageType>
+    )
+    expect(messages.value.en).toEqual({
+      hello: 'Hello,world!',
+      foo: 'foo'
+    })
+    expect(messages.value.ja).toEqual({
+      hello: 'こんにちは、世界！',
+      foo: msgFn
+    })
+  })
+
+  test('function + locale messages', () => {
+    const functions = Object.create(null)
+    const msg1 = () => {}
+    const msg2 = () => {}
+    functions[generateFormatCacheKey('en', 'hello', 'hello,world')] = msg1
+    functions[
+      generateFormatCacheKey('ja', 'hello.hello', 'こんにちは、世界')
+    ] = msg2
+    const options = {
+      __i18n: () => ({ functions }),
+      messages: {
+        en: { foo: 'foo' },
+        ja: { foo: 'ふー' }
+      }
+    }
+    const { messages } = createComposer(
+      options as ComposerOptions<VueMessageType>
+    )
+    expect(messages.value.en).toEqual({
+      hello: msg1,
+      foo: 'foo'
+    })
+    expect(messages.value.ja).toEqual({
+      hello: {
+        hello: msg2
+      },
+      foo: 'ふー'
+    })
+  })
 })
 
 describe('__transrateVNode', () => {