Fixed #43

src/Locale.ts

@@ -3,14 +3,25 @@ import { RuleType, LanguageType } from "./Types";
 
 const TRANSLATIONS: Partial<Record<LanguageType, Record<string, string>>> = {};
 
-export const setLocales = (json: any) => {
-  if (Array.isArray(json)) {
-    const locales = json as ILocale[];
+export const setLocales = (values: ILocale[] | ILocale) => {
+  if (Array.isArray(values)) {
+    const locales = values as ILocale[];
     for (const item of locales) {
-      TRANSLATIONS[item.key] = item.values;
+      mergeTranslations(item);
     }
   } else {
-    const locale = json as ILocale;
+    const locale = values as ILocale;
+    mergeTranslations(locale);
+  }
+};
+
+const mergeTranslations = (locale: ILocale) => {
+  if (TRANSLATIONS[locale.key]) {
+    TRANSLATIONS[locale.key] = {
+      ...TRANSLATIONS[locale.key],
+      ...locale.values,
+    };
+  } else {
     TRANSLATIONS[locale.key] = locale.values;
   }
 };
@@ -24,6 +35,10 @@ export const addCustomLocale = (
   ruleName: string,
   translation: string
 ) => {
+  if (!TRANSLATIONS[locale]) {
+    TRANSLATIONS[locale] = {};
+  }
+
   const root = TRANSLATIONS[locale];
 
   if (root) {
@@ -37,7 +52,7 @@ export const getMessage = (
   rule: RuleType,
   params: any[],
   language: LanguageType,
-  customTranslations: Record<string, string>
+  customTranslations: Record<string, string> = {}
 ) => {
   const defaultTranslations = TRANSLATIONS[language];
   if (defaultTranslations === undefined) {

src/ruleManager.ts

@@ -1,5 +1,5 @@
 import { RULE_FUNCTION_MAPS } from "./Constants";
-import { addCustomLocale, getLoadedLocales } from "./Locale";
+import { addCustomLocale } from "./Locale";
 import { LanguageType, RuleFunction } from "./Types";
 
 export const DEFINED_RULES: Record<string, RuleFunction> = {
@@ -15,8 +15,7 @@ export const register = (
     throw new Error(`The rule name is already defined: ${name}`);
   }
 
-  const activeLocales = getLoadedLocales();
-  for (const locale of activeLocales) {
+  for (const locale of Object.keys(translations)) {
     const message = translations[locale as LanguageType];
     if (message === undefined) {
       throw new Error(

tests/index.test.ts

@@ -9,6 +9,7 @@ import {
   register,
   en,
   tr,
+  az,
 } from "../index";
 
 const EXISTS_RULE_TRANSLATIONS = {
@@ -245,6 +246,36 @@ describe("validate() function ", () => {
     );
   });
 
+  test("should be able to register a rule before setLocales", async () => {
+    const isNullable = (value: any) => {
+      if (value === null || value === "null") {
+        return true;
+      }
+      return false;
+    };
+
+    register("nullable", isNullable, {
+      en: "The {0} field must be null or empty.",
+      tr: "The {0} field must be null or empty.",
+      az: "AZ: The {0} field must be null or empty!",
+    });
+
+    setLocales(az);
+
+    const data = {
+      email: "user@example.com",
+    };
+    const rules = {
+      email: "nullable",
+    };
+
+    const results = await validate(data, rules, { language: "az" });
+    expect(results.isValid).toBe(false);
+    expect(results.errors.email[0].message).toBe(
+      "AZ: The {0} field must be null or empty!"
+    );
+  });
+
   test("should not be able to register the same rule twice", async () => {
     expect(() =>
       register("exists", () => false, EXISTS_RULE_TRANSLATIONS)