From d1a7d93be22d1b3cffef42651a4eceefbe03f8d3 Mon Sep 17 00:00:00 2001
From: Wojciech Maj <kontakt@wojtekmaj.pl>
Date: Tue, 3 Nov 2020 13:08:23 +0100
Subject: [PATCH] Support synchronous and static languageFiles

---
 README.md             | 27 ++++++++++++++++++++-------
 src/useTranslation.js | 18 ++++++++++++++++--
 2 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/README.md b/README.md
index 0d30b1b..284792d 100644
--- a/README.md
+++ b/README.md
@@ -89,13 +89,26 @@ If `<html lang="…">` attribute is not provided the following happens:
 
 Wrap your app in `<TProvider />`.
 
-Define `languageFiles` prop that contains an object of functions that return promises:
-
-```js
-{
-  'de-DE': () => import('./myLanguageFile.json'),
-}
-```
+Define `languageFiles` prop that contains an object of:
+
+* functions that return promises:
+    ```js
+    {
+      'de-DE': () => import('./myLanguageFile.json'),
+    }
+    ```
+* functions that return language files:
+    ```js
+    {
+      'de-DE': () => myLanguageFile,
+    }
+    ```
+* language files:
+    ```js
+    {
+      'de-DE': myLanguageFile,
+    }
+    ```
 
 ### Usage of the `T` component:
 
diff --git a/src/useTranslation.js b/src/useTranslation.js
index 67d2129..83a844c 100644
--- a/src/useTranslation.js
+++ b/src/useTranslation.js
@@ -2,8 +2,22 @@ import { useContext, useState, useEffect } from 'react';
 
 import { Context } from './TProvider';
 
+function resolveLanguageFile(getterOrLanguageFile) {
+  if (!(getterOrLanguageFile instanceof Function)) {
+    return Promise.resolve(getterOrLanguageFile);
+  }
+
+  const promiseOrLanguageFile = getterOrLanguageFile();
+
+  if (!(promiseOrLanguageFile instanceof Promise)) {
+    return Promise.resolve(promiseOrLanguageFile);
+  }
+
+  return promiseOrLanguageFile;
+}
+
 function getTranslatedString(string, languageFiles, locale) {
-  return languageFiles[locale]()
+  return resolveLanguageFile(languageFiles[locale])
     .then((languageFile) => {
       if (typeof languageFile[string] === 'string') {
         return languageFile[string];
@@ -13,7 +27,7 @@ function getTranslatedString(string, languageFiles, locale) {
     })
     .catch(() => {
       // eslint-disable-next-line no-console
-      console.error(`Unable to load locale: ${locale}`);
+      console.error(`Failed to load locale: ${locale}`);
       return string;
     });
 }
-- 
2.51.2