[9.x] Use standard path helper for Application::langPath() (#40274)

* [9.x] Use standard path helper for Application::langPath()

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* Utilise `useLangPath()` instead of trying to resolve `is_dir()` on each method call.

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

* wip

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

Author: crynobone

src/Illuminate/Foundation/Application.php

@@ -313,13 +313,20 @@ protected function bindPathsInContainer()
     {
         $this->instance('path', $this->path());
         $this->instance('path.base', $this->basePath());
-        $this->instance('path.lang', $this->langPath());
         $this->instance('path.config', $this->configPath());
         $this->instance('path.public', $this->publicPath());
         $this->instance('path.storage', $this->storagePath());
         $this->instance('path.database', $this->databasePath());
         $this->instance('path.resources', $this->resourcePath());
         $this->instance('path.bootstrap', $this->bootstrapPath());
+
+        $this->useLangPath(value(function () {
+            if (is_dir($directory = $this->resourcePath('lang'))) {
+                return $directory;
+            }
+
+            return $this->basePath('lang');
+        }));
     }
 
     /**
@@ -412,19 +419,12 @@ public function useDatabasePath($path)
     /**
      * Get the path to the language files.
      *
+     * @param  string  $path
      * @return string
      */
-    public function langPath()
+    public function langPath($path = '')
     {
-        if ($this->langPath) {
-            return $this->langPath;
-        }
-
-        if (is_dir($path = $this->resourcePath().DIRECTORY_SEPARATOR.'lang')) {
-            return $path;
-        }
-
-        return $this->basePath().DIRECTORY_SEPARATOR.'lang';
+        return $this->langPath.($path ? DIRECTORY_SEPARATOR.$path : '');
     }
 
     /**

src/Illuminate/Foundation/helpers.php

@@ -492,7 +492,7 @@ function logger($message = null, array $context = [])
      */
     function lang_path($path = '')
     {
-        return app('path.lang').($path ? DIRECTORY_SEPARATOR.$path : $path);
+        return app()->langPath($path);
     }
 }