feature: add basic stub for config helper

Author: mr-feek

stubs/helpers.stubphp

@@ -116,3 +116,14 @@ function logger($message = null, array $context = [])
 
     return app('log')->debug($message, $context);
 }
+
+/**
+ * Get / set the specified configuration value.
+ *
+ * If an array is passed as the key, we will assume you want to set an array of values.
+ *
+ * @param  array<string, mixed>|string|null  $key
+ * @param  mixed  $default
+ * @return ($key is null ? \Illuminate\Config\Repository : ($key is array ? null : mixed))
+ */
+function config($key = null, $default = null) {}

tests/acceptance/ConfigTypes.feature

@@ -0,0 +1,73 @@
+Feature: Config helper
+    The global config helper will return a strict type
+
+    Background:
+        Given I have the following config
+"""
+<?xml version="1.0"?>
+<psalm errorLevel="1">
+    <projectFiles>
+        <directory name="."/>
+        <ignoreFiles> <directory name="../../vendor"/> </ignoreFiles>
+    </projectFiles>
+    <plugins>
+        <pluginClass class="Psalm\LaravelPlugin\Plugin"/>
+    </plugins>
+</psalm>
+"""
+        And I have the following code preamble
+"""
+<?php declare(strict_types=1);
+"""
+
+    Scenario: config with no arguments returns a repository instance
+        Given I have the following code
+  """
+  function test(): \Illuminate\Config\Repository {
+    return config();
+  }
+  """
+        When I run Psalm
+        Then I see no errors
+
+    Scenario: config with one argument
+        Given I have the following code
+    """
+    /**
+    * @return mixed
+    */
+    function test()
+    {
+        return config('app.name');
+    }
+    """
+        When I run Psalm
+        Then I see no errors
+
+    Scenario: config with first null argument and second argument provided
+        Given I have the following code
+    """
+    /**
+    * @return mixed
+    */
+    function test()
+    {
+        return config('app.non-existent', false);
+    }
+    """
+        When I run Psalm
+        Then I see no errors
+
+    Scenario: config setting at runtime
+        Given I have the following code
+    """
+    /**
+    * @return null
+    */
+    function test()
+    {
+        return config(['app.non-existent' => false]);
+    }
+    """
+        When I run Psalm
+        Then I see no errors