Merge instead for extend

README.md

@@ -69,7 +69,7 @@ export function extend(language: string, tokens: Record<string, any>): void;
 export function extendFromSystemPath(path: string): Promise<void>;
 ```
 
-> **Note**
+> [!NOTE]
 > Local lang must be updated otherwise `getTokenSync()` will throws. Make sure to use `await i18n.getLocalLang()` before any synchronous usage.
 
 ## Generate documentation

index.js

@@ -8,6 +8,7 @@ import { pathToFileURL } from "node:url";
 // Import Third-party Depedencies
 import cacache from "cacache";
 import lodashGet from "lodash.get";
+import deepmerge from "deepmerge";
 
 // Import Internals
 import { CACHE_PATH, CURRENT_LANG } from "./src/constants.js";
@@ -88,7 +89,7 @@ export function getTokenSync(token, ...params) {
 
 export function extend(extendLanguage, opts = {}) {
   if (extendLanguage in languages) {
-    Object.assign(languages[extendLanguage], opts);
+    languages[extendLanguage] = deepmerge(languages[extendLanguage], opts);
   }
   else {
     languages[extendLanguage] = opts;

package.json

@@ -41,6 +41,7 @@
   },
   "dependencies": {
     "cacache": "^18.0.0",
+    "deepmerge": "^4.3.1",
     "lodash.get": "^4.4.2"
   }
 }

test/i18n.js

@@ -140,6 +140,17 @@ describe("extend", () => {
     );
   });
 
+  it("should deeply extend the properties", async() => {
+    i18n.extend("english", { contributor: { name: "Fraxken" } });
+    i18n.extend("english", { contributor: { email: "gentilhomme.thomas@gmail.com" } });
+    await i18n.setLocalLang("english");
+
+    assert.deepEqual(
+      await i18n.getToken("contributor"),
+      { name: "Fraxken", email: "gentilhomme.thomas@gmail.com" }
+    );
+  });
+
   it("should add a new language if it doesn't exist", async() => {
     i18n.extend("spanish", { welcome: "Bienvenido" });