[Workflow] Deprecate worflow and single state marking

UPGRADE-4.3.md

@@ -237,6 +237,29 @@ Workflow
                    property: state
    ```
 
+ * Using a workflow with a single state marking is deprecated. Use a state machine instead.
+
+   Before:
+   ```yaml
+   framework:
+       workflows:
+           article:
+               type: workflow
+               marking_store:
+                   type: single_state
+   ```
+
+   After:
+   ```yaml
+   framework:
+       workflows:
+           article:
+               type: state_machine
+               marking_store:
+                   # type: single_state # Since the single_state marking store is deprecated, use method instead
+                   type: method
+   ```
+
 Yaml
 ----
 

UPGRADE-5.0.md

@@ -430,6 +430,27 @@ Workflow
                    property: state
    ```
 
+
+ * Support for using a workflow with a single state marking is dropped. Use a state machine instead.
+
+   Before:
+   ```yaml
+   framework:
+       workflows:
+           article:
+               type: workflow
+               marking_store:
+                   type: single_state
+   ```
+
+   After:
+   ```yaml
+   framework:
+       workflows:
+           article:
+               type: state_machine
+   ```
+
 Yaml
 ----
 

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php

@@ -474,6 +474,16 @@ class Configuration implements ConfigurationInterface
                                     })
                                     ->thenInvalid('"supports" or "support_strategy" should be configured.')
                                 ->end()
+                                ->validate()
+                                    ->ifTrue(function ($v) {
+                                        return 'workflow' === $v['type'] && 'single_state' === ($v['marking_store']['type'] ?? false);
+                                    })
+                                    ->then(function ($v) {
+                                        @trigger_error('Using a workflow with type=workflow and a marking_store=single_state is deprecated since Symfony 4.3. Use type=state_machine instead.', E_USER_DEPRECATED);
+
+                                        return $v;
+                                    })
+                                ->end()
                             ->end()
                         ->end()
                     ->end()

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/PhpFrameworkExtensionTest.php

@@ -88,6 +88,40 @@ class PhpFrameworkExtensionTest extends FrameworkExtensionTest
         });
     }
 
+    /**
+     * @group legacy
+     * @expectedDeprecation Using a workflow with type=workflow and a marking_store=single_state is deprecated since Symfony 4.3. Use type=state_machine instead.
+     */
+    public function testWorkflowDeprecateWorkflowSingleState()
+    {
+        $this->createContainerFromClosure(function ($container) {
+            $container->loadFromExtension('framework', [
+                'workflows' => [
+                    'article' => [
+                        'type' => 'workflow',
+                        'marking_store' => [
+                            'type' => 'single_state',
+                        ],
+                        'supports' => [
+                            __CLASS__,
+                        ],
+                        'places' => [
+                            'a',
+                            'b',
+                            'c',
+                        ],
+                        'transitions' => [
+                            'a_to_b' => [
+                                'from' => ['a'],
+                                'to' => ['b'],
+                            ],
+                        ],
+                    ],
+                ],
+            ]);
+        });
+    }
+
     /**
      * @group legacy
      */