feat: add locale code validation

Author: AleksandrSl

cmp/compiler/src/plugin/transform/utils.test.ts

@@ -3,7 +3,10 @@
  */
 import { describe, expect, it } from "vitest";
 import IntlMessageFormat from "intl-messageformat";
-import { escapeTextForICU } from "./utils";
+import { parse } from "@babel/parser";
+import traverse from "@babel/traverse";
+import * as t from "@babel/types";
+import { escapeTextForICU, isReactComponent } from "./utils";
 
 describe("escapeTextForICU", () => {
   it.each([

cmp/compiler/src/translation-server/cli.ts

@@ -51,6 +51,7 @@ import { logger } from "../utils/logger";
 import { startOrGetTranslationServer } from "./translation-server";
 import { createLingoConfig } from "../utils/config-factory";
 import { type LocaleCode } from "lingo.dev/spec";
+import { parseLocaleOrThrow } from "../utils/is-valid-locale";
 
 interface CLIOptions {
   port?: number;
@@ -87,13 +88,15 @@ function parseCliArgs(): CLIOptions {
     allowPositionals: false,
   });
 
+  const parsedSourceLocale = parseLocaleOrThrow(values["source-locale"]);
+  const parsedTargetLocales = values["target-locales"]
+    ?.split(",")
+    .map((s) => parseLocaleOrThrow(s));
+
   return {
     port: values.port ? parseInt(values.port, 10) : undefined,
-    // TODO (AleksandrSl 04/12/2025): Validation for LocaleCode is needed
-    sourceLocale: values["source-locale"] as LocaleCode,
-    targetLocales: values["target-locales"]
-      ?.split(",")
-      .map((s) => s.trim()) as LocaleCode[],
+    sourceLocale: parsedSourceLocale,
+    targetLocales: parsedTargetLocales,
     lingoDir: values["lingo-dir"],
     sourceRoot: values["source-root"],
     models: values.models ? parseModelsString(values.models) : undefined,

cmp/compiler/src/translation-server/translation-server.ts

@@ -30,6 +30,7 @@ import {
 import type { TranslationServerEvent } from "./ws-events";
 import { createEvent } from "./ws-events";
 import type { LocaleCode } from "lingo.dev/spec";
+import { parseLocaleOrThrow } from "../utils/is-valid-locale";
 
 export interface TranslationServerOptions {
   /**
@@ -607,20 +608,16 @@ export class TranslationServer {
       const postMatch = url.pathname.match(/^\/translations\/([^/]+)$/);
       if (postMatch && req.method === "POST") {
         const [, locale] = postMatch;
-        // TODO (AleksandrSl 14/12/2025): Validate localeCode
-        await this.handleBatchTranslationRequest(
-          locale as LocaleCode,
-          req,
-          res,
-        );
+
+        await this.handleBatchTranslationRequest(locale, req, res);
         return;
       }
 
       // Translation dictionary endpoint: GET /translations/:locale
       const dictMatch = url.pathname.match(/^\/translations\/([^/]+)$/);
       if (dictMatch && req.method === "GET") {
         const [, locale] = dictMatch;
-        await this.handleDictionaryRequest(locale as LocaleCode, res);
+        await this.handleDictionaryRequest(locale, res);
         return;
       }
 
@@ -653,11 +650,13 @@ export class TranslationServer {
    * Handle batch translation request
    */
   private async handleBatchTranslationRequest(
-    locale: LocaleCode,
+    locale: string,
     req: http.IncomingMessage,
     res: http.ServerResponse,
   ): Promise<void> {
     try {
+      const parsedLocale = parseLocaleOrThrow(locale);
+
       // Read request body
       let body = "";
       this.logger.debug("Reading request body...");
@@ -703,7 +702,7 @@ export class TranslationServer {
       try {
         // Translate using the stored service
         const result = await this.translationService.translate(
-          locale,
+          parsedLocale,
           this.metadata,
           hashes,
         );
@@ -743,10 +742,12 @@ export class TranslationServer {
    * Handle request for full translation dictionary
    */
   private async handleDictionaryRequest(
-    locale: LocaleCode,
+    locale: string,
     res: http.ServerResponse,
   ): Promise<void> {
     try {
+      const parsedLocale = parseLocaleOrThrow(locale);
+
       if (!this.translationService) {
         throw new Error("Translation service not initialized");
       }
@@ -765,7 +766,7 @@ export class TranslationServer {
 
       // Translate all hashes
       const result = await this.translationService.translate(
-        locale,
+        parsedLocale,
         this.metadata,
         allHashes,
       );

cmp/compiler/src/utils/is-valid-locale.ts

@@ -0,0 +1,20 @@
+import { isValidLocale as _isValidLocale } from "lingo.dev/locale-codes";
+import type { LocaleCode } from "lingo.dev/spec";
+
+export function isValidLocale(locale: string): locale is LocaleCode {
+  return _isValidLocale(locale);
+}
+
+export function parseLocale(
+  locale: string | undefined,
+): LocaleCode | undefined {
+  return locale && isValidLocale(locale) ? locale : undefined;
+}
+
+export function parseLocaleOrThrow(locale: string | undefined): LocaleCode {
+  if (locale && isValidLocale(locale)) {
+    return locale;
+  } else {
+    throw new Error(`Invalid locale: ${locale}`);
+  }
+}