fix: return empty if the key-value is empty value

PR-URL: https://github.com/koajs/locales/pull/17
Reviewed-By: fengmk2 <fengmk2@gmail.com>
Reviewed-By: dead-horse <heyiyu.deadhorse@gmail.com>

index.js

@@ -1,6 +1,4 @@
-/**!
- * koa-locales - index.js
- *
+/**
  * Copyright(c) koajs and other contributors.
  * MIT Licensed
  *
@@ -87,7 +85,11 @@ module.exports = function (app, options) {
     const locale = this.__getLocale();
     const resource = resources[locale] || {};
 
-    const text = resource[key] || key;
+    let text = resource[key];
+    if (text === undefined) {
+      text = key;
+    }
+
     debug('%s: %j => %j', locale, key, text);
     if (!text) {
       return '';

test/index.test.js

@@ -36,6 +36,7 @@ describe('koa-locales.test.js', function () {
         empty: '',
         notexists_key: 'key not exists',
         empty_string: '',
+        empty_value: 'emptyValue',
         novalue: 'key %s ok',
         arguments3: '1 2 3',
         arguments4: '1 2 3 4',
@@ -76,6 +77,7 @@ describe('koa-locales.test.js', function () {
         empty: '',
         notexists_key: 'key not exists',
         empty_string: '',
+        empty_value: 'emptyValue',
         novalue: 'key %s ok',
         arguments3: '1 2 3',
         arguments4: '1 2 3 4',
@@ -101,6 +103,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: '',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -125,6 +128,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: 'emptyValue',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -150,6 +154,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: '',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -174,6 +179,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: 'emptyValue',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -201,6 +207,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: '',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -232,6 +239,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: '',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -255,6 +263,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: '',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -278,6 +287,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: '',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -303,6 +313,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: 'emptyValue',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -328,6 +339,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: 'emptyValue',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -355,6 +367,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: '',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -382,6 +395,7 @@ describe('koa-locales.test.js', function () {
           empty: '',
           notexists_key: 'key not exists',
           empty_string: '',
+          empty_value: 'emptyValue',
           novalue: 'key %s ok',
           arguments3: '1 2 3',
           arguments4: '1 2 3 4',
@@ -423,6 +437,7 @@ function createApp(options) {
       empty: this[fname](),
       notexists_key: this[fname]('key not exists'),
       empty_string: this[fname](''),
+      empty_value: this[fname]('emptyValue'),
       novalue: this[fname]('key %s ok'),
       arguments3: this[fname]('%s %s %s', 1, 2, 3),
       arguments4: this[fname]('%s %s %s %s', 1, 2, 3, 4),
@@ -435,3 +450,4 @@ function createApp(options) {
 
   return app;
 }
+

test/locales/zh-CN.js

@@ -2,6 +2,7 @@
 
 module.exports = {
   Email: '邮箱',
+  emptyValue: '',
   'Hello %s, how are you today?': '%s，今天过得如何？',
   model: {
     user: {

test/locales/zh_TW.json

@@ -1,5 +1,6 @@
 {
   "Email": "郵箱",
+  "emptyValue": "",
   "Hello %s, how are you today?": "%s，今天過得如何？",
   "model": {
     "user": {