FbtTranslations: add support for modifying registered translations

CHANGELOG.md

@@ -51,6 +51,9 @@ List of changes for each released npm package version.
   <summary>
     Unreleased changes that have landed in master. Click to see more.
   </summary>
+
+  - [feat] Add a new `FbtTranslations.getRegisteredTranslations` function
+  - [feat] Add a new `FbtTranslations.mergeTranslations` function
 </details>
 
 - 0.16.5:

runtime/nonfb/FbtTranslations.js

@@ -14,7 +14,7 @@ import type {FbtRuntimeCallInput, FbtTranslatedInput} from 'FbtHooks';
 
 const FbtHooks = require('FbtHooks');
 
-let translatedFbts = null;
+let translatedFbts: TranslationDict = {};
 
 type TranslationStr = string;
 
@@ -30,7 +30,7 @@ const FbtTranslations = {
     const {args, options} = input;
     const hashKey = options?.hk;
     const {locale} = FbtHooks.getViewerContext();
-    const table = translatedFbts?.[locale];
+    const table = translatedFbts[locale];
     if (__DEV__) {
       if (!table && locale !== DEFAULT_SRC_LOCALE) {
         console.warn('Translations have not been provided');
@@ -49,6 +49,19 @@ const FbtTranslations = {
   registerTranslations(translations: TranslationDict): void {
     translatedFbts = translations;
   },
+
+  getRegisteredTranslations(): TranslationDict {
+    return translatedFbts;
+  },
+
+  mergeTranslations(newTranslations: TranslationDict): void {
+    Object.keys(newTranslations).forEach(locale => {
+      translatedFbts[locale] = Object.assign(
+        translatedFbts[locale] ?? {},
+        newTranslations[locale],
+      );
+    });
+  },
 };
 
 module.exports = FbtTranslations;

runtime/nonfb/__tests__/FbtTranslations-test.js

@@ -0,0 +1,61 @@
+// @flow
+
+import FbtTranslations from '../FbtTranslations'
+
+it('can register and get back translations', () => {
+  FbtTranslations.registerTranslations({ 'en_US': { c1: "aaa" } });
+  expect(FbtTranslations.getRegisteredTranslations()).toMatchInlineSnapshot(`
+    Object {
+      "en_US": Object {
+        "c1": "aaa",
+      },
+    }
+  `);
+})
+
+it('merges translations with the same locale as expected', () => {
+  FbtTranslations.registerTranslations({ 'en_US': { c1: "aaa" } });
+  FbtTranslations.mergeTranslations({ 'en_US': { c2: "bbb" } });
+  expect(FbtTranslations.getRegisteredTranslations()).toMatchInlineSnapshot(`
+    Object {
+      "en_US": Object {
+        "c1": "aaa",
+        "c2": "bbb",
+      },
+    }
+  `);
+})
+
+it('merges translations with different locales as expected', () => {
+  FbtTranslations.registerTranslations({ 'en_US': { c1: "aaa" } });
+  FbtTranslations.mergeTranslations({
+    'es_MX': { c1: "bbb" },
+    'cs_CZ': { c1: "ccc" },
+  });
+  expect(FbtTranslations.getRegisteredTranslations()).toMatchInlineSnapshot(`
+    Object {
+      "cs_CZ": Object {
+        "c1": "ccc",
+      },
+      "en_US": Object {
+        "c1": "aaa",
+      },
+      "es_MX": Object {
+        "c1": "bbb",
+      },
+    }
+  `);
+})
+
+it('merges translations with the same hash as expected', () => {
+  FbtTranslations.registerTranslations({ 'en_US': { c1: "aaa", c2: "bbb" } });
+  FbtTranslations.mergeTranslations({ 'en_US': { c1: "ccc" } });
+  expect(FbtTranslations.getRegisteredTranslations()).toMatchInlineSnapshot(`
+    Object {
+      "en_US": Object {
+        "c1": "ccc",
+        "c2": "bbb",
+      },
+    }
+  `);
+})