Warn on delete failure, instead of hard exiting (#376)

* Warn on delete failure, instead of hard exiting

* Add tests for e166709

* Newline at the end of the file

Co-authored-by: Pascal Birchler <pascalb@google.com>

---------

Co-authored-by: Pascal Birchler <pascalb@google.com>

Author: danielbachhuber

features/plugin-delete.feature

@@ -57,3 +57,32 @@ Feature: Delete WordPress plugins
       Success:
       """
     And the return code should be 0
+
+  Scenario: Reports a failure for a plugin that can't be deleted
+    Given a WP install
+
+    When I run `chmod -w wp-content/plugins/akismet`
+    And I try `wp plugin delete akismet`
+    Then STDERR should contain:
+      """
+      Warning: The 'akismet' plugin could not be deleted.
+      """
+    And STDERR should contain:
+      """
+      Error: No plugins deleted.
+      """
+    Then STDOUT should not contain:
+      """
+      Success:
+      """
+
+    When I run `chmod +w wp-content/plugins/akismet`
+    And I run `wp plugin delete akismet`
+    Then STDERR should not contain:
+      """
+      Error:
+      """
+    Then STDOUT should contain:
+      """
+      Success:
+      """

src/Plugin_Command.php

@@ -1113,6 +1113,7 @@ public function delete( $args, $assoc_args = array() ) {
 				WP_CLI::log( "Deleted '{$plugin->name}' plugin." );
 				++$successes;
 			} else {
+				WP_CLI::warning( "The '{$plugin->name}' plugin could not be deleted." );
 				++$errors;
 			}
 		}
@@ -1297,6 +1298,6 @@ private function delete_plugin( $plugin ) {
 			$command = 'rm -rf ';
 		}
 
-		return ! WP_CLI::launch( $command . escapeshellarg( $path ) );
+		return ! WP_CLI::launch( $command . escapeshellarg( $path ), false );
 	}
 }