[10.x] Add public path to application contract (#45969)

* Add publicPath function to Application contract

* Update public_path helper to use Application publicPath

Author: jnoordsij

src/Illuminate/Contracts/Foundation/Application.php

@@ -53,6 +53,14 @@ public function databasePath($path = '');
      */
     public function langPath($path = '');
 
+    /**
+     * Get the path to the public directory.
+     *
+     * @param  string  $path
+     * @return string
+     */
+    public function publicPath($path = '');
+
     /**
      * Get the path to the resources directory.
      *

src/Illuminate/Foundation/Application.php

@@ -481,7 +481,9 @@ public function useLangPath($path)
      */
     public function publicPath($path = '')
     {
-        return $this->joinPaths($this->basePath('public'), $path);
+        $publicPath = $this->bound('path.public') ? $this->make('path.public') : $this->basePath('public');
+
+        return $this->joinPaths($publicPath, $path);
     }
 
     /**

src/Illuminate/Foundation/helpers.php

@@ -628,7 +628,7 @@ function precognitive($callable = null)
      */
     function public_path($path = '')
     {
-        return app()->joinPaths(app()->make('path.public'), $path);
+        return app()->publicPath($path);
     }
 }