Adding function to parse language for ICU to address #35 (#63)

* Adding function to parse language for ICU * Adding missing semicolon
i18next · Apr 3, 2023 · 9615bc9 · 9615bc9
1 parent 6d65e18
commit 9615bc9
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Showing 4 changed files with 36 additions and 9 deletions.
diff --git a/README.md b/README.md
@@ -52,7 +52,11 @@ i18next.use(ICU).init(i18nextOptions);
 
   // Will be run when parser throws an error. Can return any string, which can be used as a fallback, in case of broken translation.
   // If omitted, the default swallows the error and returns the unsubstituted string (res)
-  parseErrorHandler: (err, key, res, options) => {}
+  parseErrorHandler: (err, key, res, options) => {},
+
+  // Transform the language code prior to ICU locale parsing, useful for supporting psuedo-locales like en-ZZ
+  // If omitted, the default leaves the language code as is
+  parseLngForICU: (lng) => lng,
 }
 ```
 

diff --git a/index.d.ts b/index.d.ts
@@ -25,6 +25,7 @@ declare module "i18next-icu" {
     bindI18n?: string;
     bindI18nStore?: string;
     parseErrorHandler?: (err: Error, key: string, res: string, options: Object) => string;
+    parseLngForICU?: (lng: string) => string;
   }
 
   export interface IcuInstance<TOptions = IcuConfig> extends ThirdPartyModule {
@@ -34,7 +35,7 @@ declare module "i18next-icu" {
   }
 
   interface IcuConstructor {
-    new (config?: IcuConfig): IcuInstance;
+    new(config?: IcuConfig): IcuInstance;
     type: "i18nFormat";
   }
 

diff --git a/src/index.js b/src/index.js
@@ -7,9 +7,12 @@ function getDefaults() {
     memoizeFallback: false,
     bindI18n: '',
     bindI18nStore: '',
-    parseErrorHandler: (err, key, res, options) => { 
-      return res 
-    }
+    parseErrorHandler: (err, key, res, options) => {
+      return res;
+    },
+    parseLngForICU: (lng) => {
+      return lng;
+    },
   };
 }
 
@@ -27,7 +30,7 @@ class ICU {
     this.formats = this.options.formats;
 
     if (i18next) {
-      const { bindI18n, bindI18nStore, memoize } = this.options; 
+      const { bindI18n, bindI18nStore, memoize } = this.options;
 
       i18next.IntlMessageFormat = IntlMessageFormat;
       i18next.ICU = this;
@@ -36,7 +39,7 @@ class ICU {
         if (bindI18n) {
           i18next.on(bindI18n, () => this.clearCache())
         }
-  
+
         if (bindI18nStore) {
           i18next.store.on(bindI18nStore, () => this.clearCache())
         }
@@ -59,17 +62,18 @@ class ICU {
 
     try {
       if (!fc) {
+        const transformedLng = this.options.parseLngForICU(lng);
         // without ignoreTag, react-i18next <Trans> translations with <0></0> placeholders
         // will fail to parse, as IntlMessageFormat expects them to be defined in the
         // options passed to fc.format() as { 0: (children) => string }
         // but the replacement of placeholders is done in react-i18next
-        fc = new IntlMessageFormat(res, lng, this.formats, { ignoreTag: true });
+        fc = new IntlMessageFormat(res, transformedLng, this.formats, { ignoreTag: true });
         if (this.options.memoize && (this.options.memoizeFallback || !info || hadSuccessfulLookup)) utils.setPath(this.mem, memKey, fc);
       }
 
       return fc.format(options);
     } catch (err) {
-      return this.options.parseErrorHandler(err, key,res, options);
+      return this.options.parseErrorHandler(err, key, res, options);
     }
   }
 

diff --git a/test/icu.spec.js b/test/icu.spec.js
@@ -166,6 +166,24 @@ describe("icu format", () => {
       i18next.addResourceBundle("en", "translation", { key: "value" });
       expect(spy).toHaveBeenCalledTimes(2);
     });
+
+    it("should transform the language code", () => {
+      i18next.use(ICU).init({
+        lng: "invalid-icu-language",
+        resources: {
+          "invalid-icu-language": {
+            translation: {
+              key: "Hello {who}",
+            }
+          }
+        },
+        i18nFormat: {
+          parseLngForICU: (lng) => "en-US",
+        },
+      });
+
+      expect(i18next.t("key", { who: 'world' })).toEqual("Hello world");
+    });
   });
 
   describe("with missing keys", () => {