From c5921bcaee0ff9bee2eac84b4a2c19005803ad1e Mon Sep 17 00:00:00 2001
From: Francisco Madeira <xico2k@gmail.com>
Date: Wed, 3 Jan 2024 09:47:43 +0000
Subject: [PATCH] fix: Not handling empty string translations. (#155)

---
 src/index.ts               | 23 ++++++++++++++++++-----
 test/fixtures/lang/pt.json |  3 ++-
 test/translate.test.ts     |  8 +++++++-
 3 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/src/index.ts b/src/index.ts
index 4c70d1a..25af773 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,4 +1,4 @@
-import {reactive, Plugin, computed, ComputedRef, watchEffect} from 'vue'
+import { reactive, Plugin, computed, ComputedRef, watchEffect } from 'vue'
 import { OptionsInterface } from './interfaces/options'
 import { PluginOptionsInterface } from './interfaces/plugin-options'
 import { LanguageInterface } from './interfaces/language'
@@ -349,13 +349,13 @@ export class I18n {
     }
 
     for (const [key, value] of Object.entries(this.fallbackMessages)) {
-      if (!this.activeMessages[key] || this.activeMessages[key] === key) {
+      if (!this.isValid(messages[key]) || this.activeMessages[key] === key) {
         this.activeMessages[key] = value
       }
     }
 
     for (const [key] of Object.entries(this.activeMessages)) {
-      if (!messages[key] && !this.fallbackMessages[key]) {
+      if (!this.isValid(messages[key]) && !this.isValid(this.fallbackMessages[key])) {
         this.activeMessages[key] = null
       }
     }
@@ -392,7 +392,13 @@ export class I18n {
    */
   wTrans(key: string, replacements: ReplacementsInterface = {}): ComputedRef<string> {
     watchEffect(() => {
-      this.activeMessages[key] = this.findTranslation(key) || this.findTranslation(key.replace(/\//g, '.')) || key
+      let value = this.findTranslation(key)
+
+      if (!this.isValid(value)) {
+        value = this.findTranslation(key.replace(/\//g, '.'))
+      }
+
+      this.activeMessages[key] = this.isValid(value) ? value : key
     })
 
     return computed(() => this.makeReplacements(this.activeMessages[key], replacements))
@@ -420,7 +426,7 @@ export class I18n {
    * Find translation in memory.
    */
   findTranslation(key) {
-    if (this.activeMessages[key]) {
+    if (this.isValid(this.activeMessages[key])) {
       return this.activeMessages[key]
     }
 
@@ -457,6 +463,13 @@ export class I18n {
     return message
   }
 
+  /**
+   * Checks if the message provided is valid.
+   */
+  isValid(message: string | null | undefined): boolean {
+    return message !== undefined && message !== null
+  }
+
   /**
    * Resets all the data stored in memory.
    */
diff --git a/test/fixtures/lang/pt.json b/test/fixtures/lang/pt.json
index 0dcbd72..dc78b33 100644
--- a/test/fixtures/lang/pt.json
+++ b/test/fixtures/lang/pt.json
@@ -6,5 +6,6 @@
     "foo.bar": "baz",
     "Start/end": "Início/Fim",
     "Get started.": "Comece.",
-    "<div>Welcome</div>": "<div>Bem-vindo</div>"
+    "<div>Welcome</div>": "<div>Bem-vindo</div>",
+    "Empty string": ""
 }
diff --git a/test/translate.test.ts b/test/translate.test.ts
index b7a649d..3265f42 100644
--- a/test/translate.test.ts
+++ b/test/translate.test.ts
@@ -17,6 +17,12 @@ it('translates with "trans" helper', async () => {
   expect(trans('Welcome!')).toBe('Bem-vindo!');
 })
 
+it('handles empty translations', async () => {
+  await global.mountPlugin();
+
+  expect(trans('Empty string')).toBe('');
+})
+
 it('returns the same message if there is no resolve method provided', async () => {
   const wrapper = mount({ template: `<h1>{{ $t('Welcome!') }}</h1>` }, {
     global: {
@@ -256,4 +262,4 @@ it('checks if watching wTrans works if key does not exist', async () => {
   await loadLanguageAsync('en');
 
   expect(translated.value).toBe('Not existing translation');
-})
\ No newline at end of file
+})