Issue #5960: Environment variables ignored if the value provided in t…

…he user configuration file. (#5961)

* Issue #5960: Environment variables ignored if the value provided in the user configuration file.

On-behalf-of: @salsadigitalauorg <sonny.kieu@salsa.digital>

* Issue #5960: Updated unit test.

On-behalf-of: @salsadigitalauorg <sonny.kieu@salsa.digital>

---------

Co-authored-by: Moshe Weitzman <weitzman@tejasa.com>

src/Config/ConfigLocator.php

@@ -105,11 +105,11 @@ public function __construct($envPrefix = '', $configFileVariant = '')
         // Add placeholders to establish priority. We add
         // contexts from lowest to highest priority.
         $this->config->addPlaceholder(self::DRUSH_CONTEXT);
+        $this->config->addPlaceholder(self::USER_CONTEXT);
         if (!empty($envPrefix)) {
             $envConfig = new EnvConfig($envPrefix);
             $this->config->addContext(self::ENV_CONTEXT, $envConfig);
         }
-        $this->config->addPlaceholder(self::USER_CONTEXT);
         $this->config->addPlaceholder(self::DRUPAL_CONTEXT);
         $this->config->addPlaceholder(self::SITE_CONTEXT);
         $this->config->addPlaceholder(self::ALIAS_CONTEXT);

tests/unit/ConfigLocatorTest.php

@@ -91,6 +91,25 @@ function ($item) {
         $this->assertEquals($expected, $aliasPaths);
     }
 
+    /**
+     * Test an env var supersedes user's configuration file.
+     */
+    public function testEnvVar()
+    {
+        $configLocator = $this->createConfigLocator();
+
+        $sources = $configLocator->sources();
+        $this->assertEquals($this->fixturesDir() . '/home/.drush/drush.yml', Path::canonicalize($sources['test']['home']));
+
+        $config = $configLocator->config();
+        $this->assertEquals('A user-specific setting', $config->get('test.home'));
+
+        putenv('TEST_HOME=An env overridden setting');
+        $this->assertNotEquals('A user-specific setting', $config->get('test.home'));
+        $this->assertEquals('An env overridden setting', $config->get('test.home'));
+        putenv('TEST_HOME');
+    }
+
     /**
      * Create a config locator from All The Sources, for use in multiple tests.
      */