clean install

web/modules/state_machine/tests/modules/state_machine_test/config/install/entity_test.entity_test_bundle.first.yml

@@ -0,0 +1,6 @@
+langcode: en
+status: true
+dependencies: {  }
+id: first
+label: First
+description: ''

web/modules/state_machine/tests/modules/state_machine_test/config/install/entity_test.entity_test_bundle.fourth.yml

@@ -0,0 +1,6 @@
+langcode: en
+status: true
+dependencies: {  }
+id: fourth
+label: Fourth
+description: ''

web/modules/state_machine/tests/modules/state_machine_test/config/install/entity_test.entity_test_bundle.second.yml

@@ -0,0 +1,6 @@
+langcode: en
+status: true
+dependencies: {  }
+id: second
+label: Second
+description: ''

web/modules/state_machine/tests/modules/state_machine_test/config/install/entity_test.entity_test_bundle.third.yml

@@ -0,0 +1,6 @@
+langcode: en
+status: true
+dependencies: {  }
+id: third
+label: Third
+description: ''

web/modules/state_machine/tests/modules/state_machine_test/config/install/field.field.entity_test_with_bundle.first.field_state.yml

@@ -0,0 +1,21 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - entity_test.entity_test_bundle.first
+    - field.storage.entity_test_with_bundle.field_state
+  module:
+    - state_machine
+id: entity_test_with_bundle.first.field_state
+field_name: field_state
+entity_type: entity_test_with_bundle
+bundle: first
+label: State
+description: ''
+required: false
+translatable: false
+default_value: {  }
+default_value_callback: ''
+settings:
+  workflow: default
+field_type: state

web/modules/state_machine/tests/modules/state_machine_test/config/install/field.field.entity_test_with_bundle.fourth.field_state.yml

@@ -0,0 +1,21 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - entity_test.entity_test_bundle.fourth
+    - field.storage.entity_test_with_bundle.field_state
+  module:
+    - state_machine
+id: entity_test_with_bundle.fourth.field_state
+field_name: field_state
+entity_type: entity_test_with_bundle
+bundle: fourth
+label: State
+description: ''
+required: false
+translatable: false
+default_value: {  }
+default_value_callback: ''
+settings:
+  workflow: same_transition
+field_type: state

web/modules/state_machine/tests/modules/state_machine_test/config/install/field.field.entity_test_with_bundle.second.field_state.yml

@@ -0,0 +1,21 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - entity_test.entity_test_bundle.second
+    - field.storage.entity_test_with_bundle.field_state
+  module:
+    - state_machine
+id: entity_test_with_bundle.second.field_state
+field_name: field_state
+entity_type: entity_test_with_bundle
+bundle: second
+label: State
+description: ''
+required: false
+translatable: false
+default_value: {  }
+default_value_callback: ''
+settings:
+  workflow_callback: 'state_machine_test_workflow_callback'
+field_type: state

web/modules/state_machine/tests/modules/state_machine_test/config/install/field.field.entity_test_with_bundle.third.field_state.yml

@@ -0,0 +1,21 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - entity_test.entity_test_bundle.third
+    - field.storage.entity_test_with_bundle.field_state
+  module:
+    - state_machine
+id: entity_test_with_bundle.third.field_state
+field_name: field_state
+entity_type: entity_test_with_bundle
+bundle: third
+label: State
+description: ''
+required: false
+translatable: false
+default_value: {  }
+default_value_callback: ''
+settings:
+  workflow: two_transitions
+field_type: state

web/modules/state_machine/tests/modules/state_machine_test/config/install/field.storage.entity_test_with_bundle.field_state.yml

@@ -0,0 +1,18 @@
+langcode: en
+status: true
+dependencies:
+  module:
+    - state_machine
+    - entity_test
+id: entity_test_with_bundle.field_state
+field_name: field_state
+entity_type: entity_test_with_bundle
+type: state
+settings: {  }
+module: state_machine
+locked: false
+cardinality: 1
+translatable: false
+indexes: {  }
+persist_with_no_fields: false
+custom_storage: false

web/modules/state_machine/tests/modules/state_machine_test/config/optional/views.view.state_machine_test.yml

@@ -0,0 +1,334 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - field.storage.entity_test_with_bundle.field_state
+  module:
+    - entity_test
+    - options
+    - state_machine
+id: state_machine_test
+label: 'State Machine Test'
+module: views
+description: ''
+tag: ''
+base_table: entity_test_with_bundle_field_data
+base_field: id
+core: 8.x
+display:
+  default:
+    display_plugin: default
+    id: default
+    display_title: Master
+    position: 0
+    display_options:
+      access:
+        type: none
+        options: {  }
+      cache:
+        type: tag
+        options: {  }
+      query:
+        type: views_query
+        options:
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_comment: ''
+          query_tags: {  }
+      exposed_form:
+        type: basic
+        options:
+          submit_button: Apply
+          reset_button: false
+          reset_button_label: Reset
+          exposed_sorts_label: 'Sort by'
+          expose_sort_order: true
+          sort_asc_label: Asc
+          sort_desc_label: Desc
+      pager:
+        type: mini
+        options:
+          items_per_page: 10
+          offset: 0
+          id: 0
+          total_pages: null
+          expose:
+            items_per_page: false
+            items_per_page_label: 'Items per page'
+            items_per_page_options: '5, 10, 25, 50'
+            items_per_page_options_all: false
+            items_per_page_options_all_label: '- All -'
+            offset: false
+            offset_label: Offset
+          tags:
+            previous: ‹‹
+            next: ››
+      style:
+        type: table
+      row:
+        type: fields
+      fields:
+        name:
+          table: entity_test_with_bundle_field_data
+          field: name
+          id: name
+          entity_type: null
+          entity_field: name
+          plugin_id: field
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: Name
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: value
+          type: string
+          settings: {  }
+          group_column: value
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+        field_state:
+          id: field_state
+          table: entity_test_with_bundle__field_state
+          field: field_state
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: State
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: value
+          type: list_default
+          settings: {  }
+          group_column: value
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+          plugin_id: field
+        field_state_1:
+          id: field_state_1
+          table: entity_test_with_bundle__field_state
+          field: field_state
+          relationship: none
+          group_type: group
+          admin_label: ''
+          label: Actions
+          exclude: false
+          alter:
+            alter_text: false
+            text: ''
+            make_link: false
+            path: ''
+            absolute: false
+            external: false
+            replace_spaces: false
+            path_case: none
+            trim_whitespace: false
+            alt: ''
+            rel: ''
+            link_class: ''
+            prefix: ''
+            suffix: ''
+            target: ''
+            nl2br: false
+            max_length: 0
+            word_boundary: true
+            ellipsis: true
+            more_link: false
+            more_link_text: ''
+            more_link_path: ''
+            strip_tags: false
+            trim: false
+            preserve_tags: ''
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: value
+          type: state_transition_form
+          settings: {  }
+          group_column: value
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+          plugin_id: field
+      filters:
+        field_state_value:
+          id: field_state_value
+          table: entity_test_with_bundle__field_state
+          field: field_state_value
+          relationship: none
+          group_type: group
+          admin_label: ''
+          operator: in
+          value: {  }
+          group: 1
+          exposed: true
+          expose:
+            operator_id: field_state_value_op
+            label: State
+            description: ''
+            use_operator: false
+            operator: field_state_value_op
+            identifier: field_state_value
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+              anonymous: '0'
+              administrator: '0'
+              merchant: '0'
+            reduce: false
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+          plugin_id: state_machine_state
+      sorts: {  }
+      title: 'State Machine Test'
+      header: {  }
+      footer: {  }
+      empty: {  }
+      relationships: {  }
+      arguments: {  }
+      display_extenders: {  }
+    cache_metadata:
+      max-age: -1
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url
+        - url.query_args
+      tags:
+        - 'config:field.storage.entity_test_with_bundle.field_state'
+  page_1:
+    display_plugin: page
+    id: page_1
+    display_title: Page
+    position: 1
+    display_options:
+      display_extenders: {  }
+      path: state-machine-test
+    cache_metadata:
+      max-age: -1
+      contexts:
+        - 'languages:language_content'
+        - 'languages:language_interface'
+        - url
+        - url.query_args
+      tags:
+        - 'config:field.storage.entity_test_with_bundle.field_state'

web/modules/state_machine/tests/modules/state_machine_test/src/EventSubscriber/WorkflowTransitionEventSubscriber.php

@@ -0,0 +1,123 @@
+<?php
+
+namespace Drupal\state_machine_test\EventSubscriber;
+
+use Drupal\Core\Messenger\MessengerInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\state_machine\Event\WorkflowTransitionEvent;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+class WorkflowTransitionEventSubscriber implements EventSubscriberInterface {
+
+  /**
+   * The messenger.
+   *
+   * @var \Drupal\Core\Messenger\MessengerInterface
+   */
+  protected $messenger;
+
+  /**
+   * Constructs a new WorkflowTransitionEventSubscriber object.
+   *
+   * @param \Drupal\Core\Messenger\MessengerInterface $messenger
+   *   The messenger.
+   */
+  public function __construct(MessengerInterface $messenger) {
+    $this->messenger = $messenger;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents(): array {
+    $events = [
+      'entity_test_with_bundle.create.pre_transition' => 'onPreTransition',
+      'entity_test_with_bundle.create.post_transition' => 'onPostTransition',
+      'entity_test_with_bundle.pre_transition' => 'onGroupPreTransition',
+      'entity_test_with_bundle.post_transition' => 'onGroupPostTransition',
+      'state_machine.pre_transition' => 'onGenericPreTransition',
+      'state_machine.post_transition' => 'onGenericPostTransition',
+    ];
+    return $events;
+  }
+
+  /**
+   * Reacts to the 'entity_test_with_bundle.create.pre_transition' event.
+   *
+   * @param \Drupal\state_machine\Event\WorkflowTransitionEvent $event
+   *   The transition event.
+   */
+  public function onPreTransition(WorkflowTransitionEvent $event) {
+    $this->setMessage($event, 'pre-transition');
+  }
+
+  /**
+   * Reacts to the 'entity_test_with_bundle.create.post_transition' event.
+   *
+   * @param \Drupal\state_machine\Event\WorkflowTransitionEvent $event
+   *   The transition event.
+   */
+  public function onPostTransition(WorkflowTransitionEvent $event) {
+    $this->setMessage($event, 'post-transition');
+  }
+
+  /**
+   * Reacts to the 'entity_test_with_bundle.pre_transition' event.
+   *
+   * @param \Drupal\state_machine\Event\WorkflowTransitionEvent $event
+   *   The transition event.
+   */
+  public function onGroupPreTransition(WorkflowTransitionEvent $event) {
+    $this->setMessage($event, 'group pre-transition');
+  }
+
+  /**
+   * Reacts to the 'entity_test_with_bundle.post_transition' event.
+   *
+   * @param \Drupal\state_machine\Event\WorkflowTransitionEvent $event
+   *   The transition event.
+   */
+  public function onGroupPostTransition(WorkflowTransitionEvent $event) {
+    $this->setMessage($event, 'group post-transition');
+  }
+
+  /**
+   * Reacts to the 'state_machine.pre_transition' event.
+   *
+   * @param \Drupal\state_machine\Event\WorkflowTransitionEvent $event
+   *   The transition event.
+   */
+  public function onGenericPreTransition(WorkflowTransitionEvent $event) {
+    $this->setMessage($event, 'generic pre-transition');
+  }
+
+  /**
+   * Reacts to the 'state_machine.post_transition' event.
+   *
+   * @param \Drupal\state_machine\Event\WorkflowTransitionEvent $event
+   *   The transition event.
+   */
+  public function onGenericPostTransition(WorkflowTransitionEvent $event) {
+    $this->setMessage($event, 'generic post-transition');
+  }
+
+  /**
+   * Sets a message with event information for test purposes.
+   *
+   * @param \Drupal\state_machine\Event\WorkflowTransitionEvent $event
+   *   The transition event.
+   * @param string $phase
+   *   The phase during which the event occurred.
+   */
+  protected function setMessage(WorkflowTransitionEvent $event, $phase) {
+    $this->messenger->addMessage(new TranslatableMarkup('@entity_label (@field_name) - @state_label at @phase (workflow: @workflow, transition: @transition).', [
+      '@entity_label' => (string) $event->getEntity()->label(),
+      '@field_name' => $event->getFieldName(),
+      '@state_label' => $event->getTransition()->getToState()->getLabel(),
+      '@workflow' => $event->getWorkflow()->getId(),
+      '@transition' => $event->getTransition()->getId(),
+      '@phase' => $phase,
+    ]));
+  }
+
+}

web/modules/state_machine/tests/modules/state_machine_test/src/Guard/FulfillmentGuard.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace Drupal\state_machine_test\Guard;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\state_machine\Guard\GuardInterface;
+use Drupal\state_machine\Plugin\Workflow\WorkflowInterface;
+use Drupal\state_machine\Plugin\Workflow\WorkflowTransition;
+
+class FulfillmentGuard implements GuardInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function allowed(WorkflowTransition $transition, WorkflowInterface $workflow, EntityInterface $entity) {
+    // Don't allow entities in fulfillment to be cancelled.
+    if ($transition->getId() == 'cancel' && $entity->field_state->first()->value == 'fulfillment') {
+      return FALSE;
+    }
+
+    return TRUE;
+  }
+
+}

web/modules/state_machine/tests/modules/state_machine_test/src/Guard/GenericGuard.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace Drupal\state_machine_test\Guard;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\state_machine\Guard\GuardInterface;
+use Drupal\state_machine\Plugin\Workflow\WorkflowInterface;
+use Drupal\state_machine\Plugin\Workflow\WorkflowTransition;
+
+class GenericGuard implements GuardInterface {
+
+  /**
+   * The current user.
+   *
+   * @var \Drupal\Core\Session\AccountInterface
+   */
+  protected $currentUser;
+
+  /**
+   * Constructs a new GenericGuard object.
+   *
+   * @param \Drupal\Core\Session\AccountInterface $current_user
+   *   The current user.
+   */
+  public function __construct(AccountInterface $current_user) {
+    $this->currentUser = $current_user;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function allowed(WorkflowTransition $transition, WorkflowInterface $workflow, EntityInterface $entity) {
+    // Only a "supervisor" user can cancel an entity in validation.
+    if ($transition->getId() == 'cancel' && $entity->field_state->first()->value == 'validation') {
+      return (bool) array_intersect(['merchant'], $this->currentUser->getRoles());
+    }
+
+    return TRUE;
+  }
+
+}

web/modules/state_machine/tests/modules/state_machine_test/state_machine_test.info.yml

@@ -0,0 +1,11 @@
+name: State Machine Test
+type: module
+package: Testing
+dependencies:
+  - drupal:entity_test
+  - state_machine:state_machine
+
+# Information added by Drupal.org packaging script on 2024-07-23
+version: '8.x-1.12'
+project: 'state_machine'
+datestamp: 1721740594

web/modules/state_machine/tests/modules/state_machine_test/state_machine_test.module

@@ -0,0 +1,46 @@
+<?php
+
+/**
+ * @file
+ * Test module for State Machine.
+ */
+
+use Drupal\views\EntityViewsData;
+
+/**
+ * Implements hook_entity_type_build().
+ */
+function state_machine_test_entity_type_build(array &$entity_types) {
+  $entity_types['entity_test_with_bundle']->setHandlerClass('views_data', EntityViewsData::class);
+}
+
+/**
+ * Workflow callback for the "Second" bundle of entity_test_with_bundle.
+ */
+function state_machine_test_workflow_callback() {
+  return 'validation';
+}
+
+/**
+ * Implements hook_entity_type_alter().
+ */
+function state_machine_test_entity_type_alter(array &$entity_types) {
+  /** @var \Drupal\Core\Entity\EntityTypeInterface[] $entity_types */
+  if (isset($entity_types['entity_test_with_bundle'])) {
+    $entity_types['entity_test_with_bundle']->setLinkTemplate('state-transition-form', '/entity_test_with_bundle/{entity_test_with_bundle}/{field_name}/{transition_id}');
+  }
+}
+
+/**
+ * Implements hook_module_implements_alter().
+ */
+function state_machine_test_module_implements_alter(&$implementations, $hook) {
+  // Ensure state_machine_entity_type_alter() runs after
+  // state_machine_test_entity_type_alter() which specifies the link template
+  // which is checked in state_machine_entity_type_alter().
+  if ($hook === 'entity_type_alter') {
+    $group = $implementations['state_machine'];
+    unset($implementations['state_machine']);
+    $implementations['state_machine'] = $group;
+  }
+}

web/modules/state_machine/tests/modules/state_machine_test/state_machine_test.services.yml

@@ -0,0 +1,17 @@
+services:
+  state_machine_test.fulfillment_guard:
+    class: Drupal\state_machine_test\Guard\FulfillmentGuard
+    tags:
+      - { name: state_machine.guard, group: entity_test_with_bundle }
+
+  state_machine_test.generic_guard:
+    class: Drupal\state_machine_test\Guard\GenericGuard
+    arguments: ['@current_user']
+    tags:
+      - { name: state_machine.guard }
+
+  state_machine_test.event_subscriber:
+    class: Drupal\state_machine_test\EventSubscriber\WorkflowTransitionEventSubscriber
+    arguments: ['@messenger']
+    tags:
+      - { name: event_subscriber }

web/modules/state_machine/tests/modules/state_machine_test/state_machine_test.workflow_groups.yml

@@ -0,0 +1,3 @@
+entity_test_with_bundle:
+  label: Test
+  entity_type: entity_test_with_bundle

web/modules/state_machine/tests/modules/state_machine_test/state_machine_test.workflows.yml

@@ -0,0 +1,101 @@
+default:
+  id: default
+  label: Default
+  group: entity_test_with_bundle
+  states:
+    new:
+      label: New
+    fulfillment:
+      label: Fulfillment
+    completed:
+      label: Completed
+    canceled:
+      label: Canceled
+  transitions:
+    create:
+      label: Create
+      from: [new]
+      to: fulfillment
+    fulfill:
+      label: Fulfill
+      from: [fulfillment]
+      to: completed
+    cancel:
+      label: Cancel
+      from: [new, fulfillment]
+      to: canceled
+
+validation:
+  id: validation
+  label: Validation
+  group: entity_test_with_bundle
+  states:
+    new:
+      label: New
+    validation:
+      label: Validation
+    fulfillment:
+      label: Fulfillment
+    completed:
+      label: Completed
+    canceled:
+      label: Canceled
+  transitions:
+    create:
+      label: Create
+      from: [new]
+      to: validation
+    validate:
+      label: Validate
+      from: [validation]
+      to: fulfillment
+    fulfill:
+      label: Fulfill
+      from: [fulfillment]
+      to: completed
+    cancel:
+      label: Cancel
+      from: [new, validation, fulfillment]
+      to: canceled
+
+two_transitions:
+  id: two_transitions
+  label: Two transitions
+  group: entity_test_with_bundle
+  states:
+    new:
+      label: New
+    completed:
+      label: Completed
+  transitions:
+    complete1:
+      label: Complete1
+      from: [new]
+      to:   completed
+    complete2:
+      label: Complete2
+      from: [new]
+      to:   completed
+
+same_transition:
+  id: same_transition
+  label: Contains transition to same state.
+  group: entity_test_with_bundle
+  states:
+    new:
+      label: New
+    completed:
+      label: Completed
+  transitions:
+    complete1:
+      label: Complete1
+      from: [new]
+      to:   completed
+    complete2:
+      label: Complete2
+      from: [new]
+      to:   completed
+    same:
+      label: Stay same
+      from: [new]
+      to: new

web/modules/state_machine/tests/src/Functional/StateFilterTest.php

@@ -0,0 +1,82 @@
+<?php
+
+namespace Drupal\Tests\state_machine\Functional;
+
+use Drupal\entity_test\Entity\EntityTestWithBundle;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests the Views state filter.
+ *
+ * @group state_machine
+ */
+class StateFilterTest extends BrowserTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'entity_test',
+    'options',
+    'state_machine',
+    'state_machine_test',
+    'views',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $user = $this->drupalCreateUser(['administer entity_test content']);
+    $this->drupalLogin($user);
+  }
+
+  /**
+   * Tests the filter.
+   */
+  public function testFilter() {
+    $first_entity = EntityTestWithBundle::create([
+      'type' => 'first',
+      'name' => 'First',
+    ]);
+    $first_entity->save();
+
+    $second_entity = EntityTestWithBundle::create([
+      'type' => 'second',
+      'name' => 'Second',
+      'field_state' => 'validation',
+    ]);
+    $second_entity->save();
+
+    $this->drupalGet('/state-machine-test');
+    $this->assertSession()->pageTextContains('First');
+    $this->assertSession()->pageTextContains('New');
+
+    $this->assertSession()->pageTextContains('Second');
+    $this->assertSession()->pageTextContains('Validation');
+
+    // Confirm that the states from both workflows are in the dropdown.
+    $expected_options = [
+      'All' => '- Any -',
+      'new' => 'New',
+      'validation' => 'Validation',
+      'fulfillment' => 'Fulfillment',
+      'completed' => 'Completed',
+      'canceled' => 'Canceled',
+    ];
+    $elements = $this->xpath('//select[@name="field_state_value"]/option');
+    $found_options = [];
+    foreach ($elements as $element) {
+      $found_options[$element->getValue()] = $element->getText();
+    }
+    $this->assertEquals($expected_options, $found_options);
+  }
+
+}

web/modules/state_machine/tests/src/Functional/StateTransitionFormTest.php

@@ -0,0 +1,153 @@
+<?php
+
+namespace Drupal\Tests\state_machine\Functional;
+
+use Drupal\Core\Entity\Entity\EntityViewDisplay;
+use Drupal\Core\Url;
+use Drupal\entity_test\Entity\EntityTestWithBundle;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests the state transition form.
+ *
+ * @group state_machine
+ */
+class StateTransitionFormTest extends BrowserTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'entity_test',
+    'options',
+    'state_machine',
+    'state_machine_test',
+    'views',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $user = $this->drupalCreateUser(['administer entity_test content', 'view test entity']);
+    $this->drupalLogin($user);
+  }
+
+  /**
+   * Tests the transition form.
+   */
+  public function testForm() {
+    $first_entity = EntityTestWithBundle::create([
+      'type' => 'first',
+      'name' => 'First',
+    ]);
+    $first_entity->save();
+
+    $second_entity = EntityTestWithBundle::create([
+      'type' => 'second',
+      'name' => 'Second',
+      'field_state' => 'validation',
+    ]);
+    $second_entity->save();
+
+    $this->drupalGet('/state-machine-test');
+    $this->assertSession()->pageTextContains('First');
+    $this->assertSession()->pageTextContains('New');
+    $buttons = $this->xpath('//form[@id="state-machine-transition-form-entity-test-with-bundle-field-state-1"]/div/input');
+    $this->assertCount(2, $buttons);
+    $this->assertEquals('Create', $buttons[0]->getValue());
+    $this->assertEquals('Cancel', $buttons[1]->getValue());
+
+    $this->assertSession()->pageTextContains('Second');
+    $this->assertSession()->pageTextContains('Validation');
+    $buttons = $this->xpath('//form[@id="state-machine-transition-form-entity-test-with-bundle-field-state-2"]/div/input');
+    $this->assertCount(1, $buttons);
+    $this->assertEquals('Validate', $buttons[0]->getValue());
+
+    // Click the Validate button.
+    $buttons[0]->click();
+    $this->assertSession()->pageTextContains('First');
+    $this->assertSession()->pageTextContains('New');
+    $buttons = $this->xpath('//form[@id="state-machine-transition-form-entity-test-with-bundle-field-state-1"]/div/input');
+    $this->assertCount(2, $buttons);
+    $this->assertEquals('Create', $buttons[0]->getValue());
+    $this->assertEquals('Cancel', $buttons[1]->getValue());
+    $this->assertSession()->buttonExists('Create');
+
+    $this->assertSession()->pageTextContains('Second');
+    $this->assertSession()->pageTextContains('Fulfillment');
+    $buttons = $this->xpath('//form[@id="state-machine-transition-form-entity-test-with-bundle-field-state-2"]/div/input');
+    $this->assertCount(1, $buttons);
+    $this->assertEquals('Fulfill', $buttons[0]->getValue());
+  }
+
+  /**
+   * Tests the confirmation form.
+   */
+  public function testConfirmationForm() {
+    $view_display = EntityViewDisplay::create([
+      'targetEntityType' => 'entity_test_with_bundle',
+      'bundle' => 'first',
+      'mode' => 'default',
+      'status' => TRUE,
+    ]);
+    $view_display->setComponent('field_state', [
+      'type' => 'state_transition_form',
+      'settings' => [
+        'require_confirmation' => TRUE,
+      ],
+    ]);
+    $view_display->save();
+    $first_entity = EntityTestWithBundle::create([
+      'type' => 'first',
+      'name' => 'First',
+    ]);
+    $first_entity->save();
+    $this->drupalGet($first_entity->toUrl('canonical'));
+    $this->assertSession()->pageTextContains('First');
+    $buttons = $this->xpath('//form[@id="state-machine-transition-form-entity-test-with-bundle-field-state-1"]/div/a');
+    $this->assertCount(2, $buttons);
+    $this->assertEquals('Create', $buttons[0]->getText());
+    $this->assertEquals('Cancel', $buttons[1]->getText());
+    $this->assertSession()->linkExists('Create');
+    // Click the Create button.
+    $buttons[0]->click();
+    $this->assertSession()->pageTextContains('Are you sure you want to apply this transition?');
+    $this->assertSession()->pageTextContains('From: New');
+    $this->assertSession()->pageTextContains('To: Fulfillment');
+    $this->assertSession()->pageTextContains('Transition: Create');
+    $this->assertSession()->pageTextContains('Test entity with bundle: First');
+    $this->assertSession()->pageTextContains('This action cannot be undone.');
+    $this->assertSession()->linkExists('Cancel');
+    $this->submitForm([], 'Confirm');
+
+    $buttons = $this->xpath('//form[@id="state-machine-transition-form-entity-test-with-bundle-field-state-1"]/div/a');
+    $this->assertCount(1, $buttons);
+    $this->assertEquals('Fulfill', $buttons[0]->getText());
+
+    $transitions = [
+      'create' => 403,
+      'cancel' => 403,
+      'fulfill' => 200,
+    ];
+    // Ensure the state transition form route doesn't allow access for
+    // transitions that are not allowed.
+    foreach ($transitions as $transition_id => $expected_status_code) {
+      $route = Url::fromRoute('entity.entity_test_with_bundle.state_transition_form', [
+        'entity_test_with_bundle' => $first_entity->id(),
+        'field_name' => 'field_state',
+        'transition_id' => $transition_id,
+      ]);
+      $this->drupalGet($route);
+      $this->assertSession()->statusCodeEquals($expected_status_code);
+    }
+  }
+
+}

web/modules/state_machine/tests/src/FunctionalJavascript/StateTransitionFormTest.php

@@ -0,0 +1,82 @@
+<?php
+
+namespace Drupal\Tests\state_machine\FunctionalJavascript;
+
+use Drupal\Core\Entity\Entity\EntityViewDisplay;
+use Drupal\entity_test\Entity\EntityTestWithBundle;
+use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
+
+/**
+ * Tests the state transition form.
+ *
+ * @group state_machine
+ */
+class StateTransitionFormTest extends WebDriverTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'entity_test',
+    'state_machine_test',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $user = $this->drupalCreateUser(['administer entity_test content', 'view test entity']);
+    $this->drupalLogin($user);
+  }
+
+  /**
+   * Tests the confirmation form rendered in a modal.
+   */
+  public function testConfirmationFormWithModal() {
+    $view_display = EntityViewDisplay::create([
+      'targetEntityType' => 'entity_test_with_bundle',
+      'bundle' => 'first',
+      'mode' => 'default',
+      'status' => TRUE,
+    ]);
+    $view_display->setComponent('field_state', [
+      'type' => 'state_transition_form',
+      'settings' => [
+        'require_confirmation' => TRUE,
+        'use_modal' => TRUE,
+      ],
+    ]);
+    $view_display->save();
+    $first_entity = EntityTestWithBundle::create([
+      'type' => 'first',
+      'name' => 'First',
+    ]);
+    $first_entity->save();
+    $this->drupalGet($first_entity->toUrl('canonical'));
+    $this->assertSession()->pageTextContains('First');
+
+    $buttons = $this->xpath('//form[@id="state-machine-transition-form-entity-test-with-bundle-field-state-1"]/div/a');
+    $this->assertCount(2, $buttons);
+    $this->assertEquals('Create', $buttons[0]->getText());
+    $this->assertEquals('Cancel', $buttons[1]->getText());
+    // Click the Create link.
+    $buttons[0]->click();
+    $this->assertSession()->assertWaitOnAjaxRequest();
+    $this->assertSession()->pageTextContains('Are you sure you want to apply this transition?');
+    $this->assertSession()->pageTextContains('From: New');
+    $this->assertSession()->pageTextContains('To: Fulfillment');
+    $this->assertSession()->pageTextContains('Transition: Create');
+    $this->assertSession()->pageTextContains('Test entity with bundle: First');
+    $this->assertSession()->pageTextContains('This action cannot be undone.');
+    $this->assertSession()->linkExists('Cancel');
+    $this->assertSession()->buttonExists('Confirm');
+  }
+
+}

web/modules/state_machine/tests/src/Kernel/StateItemTest.php

@@ -0,0 +1,196 @@
+<?php
+
+namespace Drupal\Tests\state_machine\Kernel;
+
+use Drupal\entity_test\Entity\EntityTestWithBundle;
+use Drupal\Tests\field\Kernel\FieldKernelTestBase;
+
+/**
+ * @coversDefaultClass \Drupal\state_machine\Plugin\Field\FieldType\StateItem
+ * @group state_machine
+ */
+class StateItemTest extends FieldKernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'entity_test',
+    'field',
+    'user',
+    'state_machine',
+    'state_machine_test',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->installEntitySchema('user');
+    $this->installEntitySchema('entity_test_with_bundle');
+    $this->installConfig(['state_machine_test']);
+  }
+
+  /**
+   * @covers ::applyTransitionById
+   */
+  public function testInvalidTransitionApply() {
+    $entity = EntityTestWithBundle::create([
+      'name' => 'first',
+      'type' => 'first',
+    ]);
+    /** @var \Drupal\state_machine\Plugin\Field\FieldType\StateItemInterface $state_item */
+    $state_item = $entity->get('field_state')->first();
+    $this->expectException(\InvalidArgumentException::class);
+    $state_item->applyTransitionById('INVALID');
+  }
+
+  /**
+   * @dataProvider providerTestField
+   */
+  public function testField($initial_state, $allowed_transitions, $invalid_new_state, $valid_transition, $expected_new_state) {
+    $entity = EntityTestWithBundle::create([
+      'name' => 'second',
+      'type' => 'second',
+      'field_state' => $initial_state,
+    ]);
+    $this->assertEquals($initial_state, $entity->get('field_state')->value);
+
+    /** @var \Drupal\state_machine\Plugin\Field\FieldType\StateItemInterface $state_item */
+    $state_item = $entity->get('field_state')->first();
+    // Confirm that the transitions are correct.
+    $transitions = $state_item->getTransitions();
+    $this->assertCount(count($allowed_transitions), $transitions);
+    $this->assertEquals($allowed_transitions, array_keys($transitions));
+    if (count($allowed_transitions) > 0) {
+      foreach ($allowed_transitions as $transition_id) {
+        $this->assertTrue($state_item->isTransitionAllowed($transition_id));
+      }
+    }
+    $this->assertFalse($state_item->isTransitionAllowed('foo'));
+    // Confirm that invalid states are recognized.
+    if ($invalid_new_state) {
+      $state_item->value = $invalid_new_state;
+      $this->assertEquals($initial_state, $state_item->getOriginalId());
+      $this->assertEquals($invalid_new_state, $state_item->getId());
+      $this->assertFalse($state_item->isValid());
+    }
+
+    // Revert to the initial state because the valid transaction could be
+    // invalid from the invalid_new_state.
+    $state_item->value = $initial_state;
+
+    // Retrieve all workflow transitions.
+    $workflow = $state_item->getWorkflow();
+    $all_transitions = $workflow->getTransitions();
+    // Pick a random invalid transition and assert it throws an Exception.
+    $invalid_transitions = array_diff_key($all_transitions, $transitions);
+    if ($invalid_transitions) {
+      $random_key = array_rand($invalid_transitions);
+      $this->expectException(\InvalidArgumentException::class);
+      $state_item->applyTransition($invalid_transitions[$random_key]);
+      // Also try applying by ID.
+      $this->expectException(\InvalidArgumentException::class);
+      $state_item->applyTransitionById($random_key);
+    }
+
+    $state_item->applyTransitionById($valid_transition);
+    $this->assertEquals($initial_state, $state_item->getOriginalId());
+    $this->assertEquals($expected_new_state, $state_item->getId());
+    $this->assertTrue($state_item->isValid());
+  }
+
+  /**
+   * Data provider for ::testField.
+   *
+   * @return array
+   *   A list of testField function arguments.
+   */
+  public static function providerTestField() {
+    $data = [];
+    $data['new->validation'] = ['new', ['create', 'cancel'], 'fulfillment', 'create', 'validation'];
+    $data['new->canceled'] = ['new', ['create', 'cancel'], 'completed', 'cancel', 'canceled'];
+    // The workflow defines validation->fulfillment and validation->canceled
+    // transitions, but the second one is forbidden by the GenericGuard.
+    $data['validation->fulfillment'] = ['validation', ['validate'], 'completed', 'validate', 'fulfillment'];
+    // The workflow defines fulfillment->completed and fulfillment->canceled
+    // transitions, but the second one is forbidden by the FulfillmentGuard.
+    $data['fulfillment->completed'] = ['fulfillment', ['fulfill'], 'new', 'fulfill', 'completed'];
+
+    return $data;
+  }
+
+  /**
+   * @dataProvider providerSettableOptions
+   */
+  public function testSettableOptions($initial_state, $available_options) {
+    $entity = EntityTestWithBundle::create([
+      'name' => 'second',
+      'type' => 'second',
+      'field_state' => $initial_state,
+    ]);
+    $this->assertEquals($initial_state, $entity->get('field_state')->value);
+    // An invalid state should not have any settable options.
+    $this->assertEquals($available_options, $entity->get('field_state')->first()->getSettableOptions());
+  }
+
+  /**
+   * Data provider for ::providerSettableOptions.
+   *
+   * @return array
+   *   A list of providerSettableOptions function arguments.
+   */
+  public static function providerSettableOptions() {
+    $data = [];
+    $data['new'] = ['new', ['canceled' => 'Canceled', 'validation' => 'Validation', 'new' => 'New']];
+    $data['invalid'] = ['invalid', []];
+
+    return $data;
+  }
+
+  /**
+   * @covers ::generateSampleValue
+   */
+  public function testGenerateSampleValue() {
+    $entity = EntityTestWithBundle::create([
+      'name' => 'first',
+      'type' => 'first',
+      'field_state' => NULL,
+    ]);
+    $entity->field_state->generateSampleItems();
+    /** @var \Drupal\state_machine\Plugin\Field\FieldType\StateItemInterface $state_item */
+    $state_item = $entity->get('field_state')->first();
+    $this->assertEquals('default', $state_item->getWorkflow()->getId());
+    $this->assertNotEmpty($state_item->getId());
+    $this->assertTrue(in_array($state_item->getId(), array_keys($state_item->getWorkflow()->getStates())));
+    $this->entityValidateAndSave($entity);
+
+    $entity = EntityTestWithBundle::create([
+      'name' => 'second',
+      'type' => 'second',
+      'field_state' => NULL,
+    ]);
+    $entity->field_state->generateSampleItems();
+    /** @var \Drupal\state_machine\Plugin\Field\FieldType\StateItemInterface $state_item */
+    $state_item = $entity->get('field_state')->first();
+    $this->assertNotEmpty($state_item->getId());
+    $this->assertTrue(in_array($state_item->getId(), array_keys($state_item->getWorkflow()->getStates())));
+    $this->entityValidateAndSave($entity);
+
+    $entity = EntityTestWithBundle::create([
+      'name' => 'third',
+      'type' => 'third',
+      'field_state' => NULL,
+    ]);
+    $entity->field_state->generateSampleItems();
+    /** @var \Drupal\state_machine\Plugin\Field\FieldType\StateItemInterface $state_item */
+    $state_item = $entity->get('field_state')->first();
+    $this->assertEquals('two_transitions', $state_item->getWorkflow()->getId());
+    $this->assertNotEmpty($state_item->getId());
+    $this->assertTrue(in_array($state_item->getId(), array_keys($state_item->getWorkflow()->getStates())));
+    $this->entityValidateAndSave($entity);
+  }
+
+}

web/modules/state_machine/tests/src/Kernel/WorkflowTransitionEventTest.php

@@ -0,0 +1,155 @@
+<?php
+
+namespace Drupal\Tests\state_machine\Kernel;
+
+use Drupal\entity_test\Entity\EntityTestWithBundle;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests the TransitionEvent.
+ *
+ * @group state_machine
+ */
+class WorkflowTransitionEventTest extends KernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'entity_test',
+    'field',
+    'user',
+    'state_machine',
+    'state_machine_test',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->installEntitySchema('user');
+    $this->installEntitySchema('entity_test_with_bundle');
+    $this->installConfig(['state_machine_test']);
+  }
+
+  /**
+   * Tests the transition event.
+   */
+  public function testTransitionEvent() {
+    $entity = EntityTestWithBundle::create([
+      'type' => 'first',
+      'name' => 'Test entity',
+      'field_state' => 'new',
+    ]);
+    $entity->save();
+
+    $entity->get('field_state')->first()->applyTransitionById('create');
+    $entity->save();
+
+    $messages = \Drupal::messenger()->all();
+    $message = reset($messages);
+    $this->assertCount(6, $message);
+    $this->assertEquals('Test entity (field_state) - Fulfillment at pre-transition (workflow: default, transition: create).', (string) $message[0]);
+    $this->assertEquals('Test entity (field_state) - Fulfillment at group pre-transition (workflow: default, transition: create).', (string) $message[1]);
+    $this->assertEquals('Test entity (field_state) - Fulfillment at generic pre-transition (workflow: default, transition: create).', (string) $message[2]);
+    $this->assertEquals('Test entity (field_state) - Fulfillment at post-transition (workflow: default, transition: create).', (string) $message[3]);
+    $this->assertEquals('Test entity (field_state) - Fulfillment at group post-transition (workflow: default, transition: create).', (string) $message[4]);
+    $this->assertEquals('Test entity (field_state) - Fulfillment at generic post-transition (workflow: default, transition: create).', (string) $message[5]);
+
+    \Drupal::messenger()->deleteAll();
+    $entity->get('field_state')->first()->applyTransitionById('fulfill');
+    $entity->save();
+
+    $messages = \Drupal::messenger()->all();
+    $message = reset($messages);
+    $this->assertCount(4, $message);
+    $this->assertEquals('Test entity (field_state) - Completed at group pre-transition (workflow: default, transition: fulfill).', (string) $message[0]);
+    $this->assertEquals('Test entity (field_state) - Completed at generic pre-transition (workflow: default, transition: fulfill).', (string) $message[1]);
+    $this->assertEquals('Test entity (field_state) - Completed at group post-transition (workflow: default, transition: fulfill).', (string) $message[2]);
+    $this->assertEquals('Test entity (field_state) - Completed at generic post-transition (workflow: default, transition: fulfill).', (string) $message[3]);
+
+    \Drupal::messenger()->deleteAll();
+    $entity = EntityTestWithBundle::create([
+      'type' => 'first',
+      'name' => 'Test entity 2',
+      'field_state' => 'new',
+    ]);
+    $entity->save();
+    $entity->get('field_state')->first()->applyTransitionById('create');
+    $entity->save();
+
+    $messages = \Drupal::messenger()->all();
+    $message = reset($messages);
+    $this->assertCount(6, $message);
+    $this->assertEquals('Test entity 2 (field_state) - Fulfillment at pre-transition (workflow: default, transition: create).', (string) $message[0]);
+    $this->assertEquals('Test entity 2 (field_state) - Fulfillment at group pre-transition (workflow: default, transition: create).', (string) $message[1]);
+    $this->assertEquals('Test entity 2 (field_state) - Fulfillment at generic pre-transition (workflow: default, transition: create).', (string) $message[2]);
+    $this->assertEquals('Test entity 2 (field_state) - Fulfillment at post-transition (workflow: default, transition: create).', (string) $message[3]);
+    $this->assertEquals('Test entity 2 (field_state) - Fulfillment at group post-transition (workflow: default, transition: create).', (string) $message[4]);
+    $this->assertEquals('Test entity 2 (field_state) - Fulfillment at generic post-transition (workflow: default, transition: create).', (string) $message[5]);
+
+    \Drupal::messenger()->deleteAll();
+    // Ensure manually setting the state to "create", triggers the cancel
+    // transition and not the 'fulfill' transition previously applied.
+    $entity->set('field_state', 'canceled');
+    $entity->save();
+    $messages = \Drupal::messenger()->all();
+    $message = reset($messages);
+    $this->assertCount(4, $message);
+    $this->assertEquals('Test entity 2 (field_state) - Canceled at group pre-transition (workflow: default, transition: cancel).', (string) $message[0]);
+    $this->assertEquals('Test entity 2 (field_state) - Canceled at generic pre-transition (workflow: default, transition: cancel).', (string) $message[1]);
+    $this->assertEquals('Test entity 2 (field_state) - Canceled at group post-transition (workflow: default, transition: cancel).', (string) $message[2]);
+    $this->assertEquals('Test entity 2 (field_state) - Canceled at generic post-transition (workflow: default, transition: cancel).', (string) $message[3]);
+  }
+
+  /**
+   * Tests the transition event with two identical to and from states.
+   */
+  public function testTransitionEventTwoTransitions() {
+    $entity = EntityTestWithBundle::create([
+      'type' => 'third',
+      'name' => 'Test entity',
+      'field_state' => 'new',
+    ]);
+    $entity->save();
+
+    // Test that applying the second transition also throws the second transition's event.
+    $entity->get('field_state')->first()->applyTransitionById('complete2');
+    $entity->save();
+
+    $messages = \Drupal::messenger()->all();
+    $message = reset($messages);
+    $this->assertCount(4, $message);
+    $this->assertEquals('Test entity (field_state) - Completed at group pre-transition (workflow: two_transitions, transition: complete2).', (string) $message[0]);
+    $this->assertEquals('Test entity (field_state) - Completed at generic pre-transition (workflow: two_transitions, transition: complete2).', (string) $message[1]);
+    $this->assertEquals('Test entity (field_state) - Completed at group post-transition (workflow: two_transitions, transition: complete2).', (string) $message[2]);
+    $this->assertEquals('Test entity (field_state) - Completed at generic post-transition (workflow: two_transitions, transition: complete2).', (string) $message[3]);
+  }
+
+  /**
+   * Tests the transition event when a state transition occurs to same value.
+   */
+  public function testTransitionEventSameState() {
+    $entity = EntityTestWithBundle::create([
+      'type' => 'fourth',
+      'name' => 'Test entity',
+      'field_state' => 'new',
+    ]);
+    $entity->save();
+
+    // Test that explicitly specifying the transition to same fires event.
+    $entity->get('field_state')->first()->applyTransitionById('same');
+    $entity->save();
+    $messages = \Drupal::messenger()->all();
+    $this->assertCount(4, $messages['status']);
+    \Drupal::messenger()->deleteAll();
+
+    // Test that simply setting the value to same as existing does not dispatch.
+    $entity->get('field_state')->first()->setValue('new');
+    $entity->save();
+    $this->assertEmpty(\Drupal::messenger()->all());
+  }
+
+}

web/modules/state_machine/tests/src/Unit/Plugin/Workflow/WorkflowTest.php

@@ -0,0 +1,246 @@
+<?php
+
+namespace Drupal\Tests\state_machine\Unit\Plugin\Workflow;
+
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\StringTranslation\TranslationInterface;
+use Drupal\state_machine\Guard\GuardFactoryInterface;
+use Drupal\state_machine\Guard\GuardInterface;
+use Drupal\state_machine\Plugin\Workflow\Workflow;
+use Drupal\Tests\UnitTestCase;
+use Prophecy\Argument;
+
+/**
+ * @coversDefaultClass \Drupal\state_machine\Plugin\Workflow\Workflow
+ * @group state_machine
+ */
+class WorkflowTest extends UnitTestCase {
+
+  /**
+   * @covers ::getId
+   */
+  public function testGetId() {
+    $guard_factory = $this->prophesize(GuardFactoryInterface::class);
+    $plugin_definition = [
+      'id' => 'test id',
+      'label' => 'test label',
+      'states' => [],
+      'transitions' => [],
+    ];
+    $workflow = new Workflow([], 'test', $plugin_definition, $guard_factory->reveal());
+
+    $this->assertEquals('test id', $workflow->getId());
+  }
+
+  /**
+   * @covers ::getLabel
+   */
+  public function testGetLabel() {
+    $guard_factory = $this->prophesize(GuardFactoryInterface::class);
+    $plugin_definition = [
+      'states' => [],
+      'transitions' => [],
+      'label' => 'test label',
+    ];
+    $workflow = new Workflow([], 'test', $plugin_definition, $guard_factory->reveal());
+
+    $this->assertEquals('test label', $workflow->getLabel());
+  }
+
+  /**
+   * @covers ::getStates
+   * @covers ::getState
+   */
+  public function testGetStates() {
+    $guard_factory = $this->prophesize(GuardFactoryInterface::class);
+    $translation = $this->prophesize(TranslationInterface::class);
+    $translation->translateString(Argument::type(TranslatableMarkup::class))
+      ->willReturn('Draft');
+    $plugin_definition = [
+      'states' => [
+        'draft' => [
+          'label' => 'Draft',
+        ],
+      ],
+      'transitions' => [],
+    ];
+    $workflow = new Workflow([], 'test', $plugin_definition, $guard_factory->reveal());
+    $workflow->setStringTranslation($translation->reveal());
+
+    $state = $workflow->getState('draft');
+    $this->assertEquals('draft', $state->getId());
+    $state->setStringTranslation($translation->reveal());
+    $this->assertEquals('Draft', $state->getLabel());
+    $this->assertEquals(['draft' => $state], $workflow->getStates());
+  }
+
+  /**
+   * @covers ::getTransitions
+   * @covers ::getTransition
+   */
+  public function testGetTransitions() {
+    $translation = $this->prophesize(TranslationInterface::class);
+    $translation->translateString(Argument::type(TranslatableMarkup::class))
+      ->willReturn('Publish');
+    $guard_factory = $this->prophesize(GuardFactoryInterface::class);
+    $plugin_definition = [
+      'states' => [
+        'draft' => [
+          'label' => 'Draft',
+        ],
+        'published' => [
+          'label' => 'Published',
+        ],
+      ],
+      'transitions' => [
+        'publish' => [
+          'label' => 'Publish',
+          'from' => ['draft'],
+          'to' => 'published',
+        ],
+      ],
+    ];
+    $workflow = new Workflow([], 'test', $plugin_definition, $guard_factory->reveal());
+
+    $transition = $workflow->getTransition('publish');
+    $transition->setStringTranslation($translation->reveal());
+    $this->assertEquals('publish', $transition->getId());
+    $this->assertEquals('Publish', $transition->getLabel());
+    $this->assertEquals(['draft' => $workflow->getState('draft')], $transition->getFromStates());
+    $this->assertEquals($workflow->getState('published'), $transition->getToState());
+    $this->assertEquals(['publish' => $transition], $workflow->getTransitions());
+  }
+
+  /**
+   * @covers ::getPossibleTransitions
+   */
+  public function testGetPossibleTransitions() {
+    $guard_factory = $this->prophesize(GuardFactoryInterface::class);
+    $plugin_definition = [
+      'states' => [
+        'draft' => [
+          'label' => 'Draft',
+        ],
+        'review' => [
+          'label' => 'Review',
+        ],
+        'published' => [
+          'label' => 'Published',
+        ],
+      ],
+      'transitions' => [
+        'send_to_review' => [
+          'label' => 'Send to review',
+          'from' => ['draft'],
+          'to' => 'review',
+        ],
+        'publish' => [
+          'label' => 'Publish',
+          'from' => ['review'],
+          'to' => 'published',
+        ],
+      ],
+    ];
+    $workflow = new Workflow([], 'test', $plugin_definition, $guard_factory->reveal());
+
+    $transition = $workflow->getTransition('send_to_review');
+    $this->assertEquals(['send_to_review' => $transition], $workflow->getPossibleTransitions('draft'));
+    $transition = $workflow->getTransition('publish');
+    $this->assertEquals(['publish' => $transition], $workflow->getPossibleTransitions('review'));
+    $this->assertEquals([], $workflow->getPossibleTransitions('published'));
+    // Passing an empty state should return all transitions.
+    $this->assertEquals($workflow->getTransitions(), $workflow->getPossibleTransitions(''));
+  }
+
+  /**
+   * @covers ::getAllowedTransitions
+   */
+  public function testGetAllowedTransitions() {
+    $plugin_definition = [
+      'states' => [
+        'draft' => [
+          'label' => 'Draft',
+        ],
+        'review' => [
+          'label' => 'Review',
+        ],
+        'published' => [
+          'label' => 'Published',
+        ],
+      ],
+      'transitions' => [
+        'send_to_review' => [
+          'label' => 'Send to review',
+          'from' => ['draft'],
+          'to' => 'review',
+        ],
+        'publish' => [
+          'label' => 'Publish',
+          'from' => ['review'],
+          'to' => 'published',
+        ],
+      ],
+      'group' => 'default',
+    ];
+    $guard_allow = $this->prophesize(GuardInterface::class);
+    $guard_allow
+      ->allowed(Argument::cetera())
+      ->willReturn(TRUE);
+    $guard_deny_publish = $this->prophesize(GuardInterface::class);
+    $guard_deny_publish
+      ->allowed(Argument::cetera())
+      ->will(function ($args) {
+        // Allow only the send_to_review transition.
+        return $args[0]->getId() == 'send_to_review';
+      });
+    $guard_factory = $this->prophesize(GuardFactoryInterface::class);
+    $guard_factory
+      ->get('default')
+      ->willReturn([$guard_allow->reveal(), $guard_deny_publish->reveal()]);
+    $workflow = new Workflow([], 'test', $plugin_definition, $guard_factory->reveal());
+
+    $entity = $this->prophesize(EntityInterface::class)->reveal();
+    $transition = $workflow->getTransition('send_to_review');
+    $this->assertEquals(['send_to_review' => $transition], $workflow->getAllowedTransitions('draft', $entity));
+    $this->assertEquals([], $workflow->getAllowedTransitions('review', $entity));
+  }
+
+  /**
+   * @covers ::findTransition
+   */
+  public function testFindTransition() {
+    $guard_factory = $this->prophesize(GuardFactoryInterface::class);
+    $plugin_definition = [
+      'states' => [
+        'draft' => [
+          'label' => 'Draft',
+        ],
+        'review' => [
+          'label' => 'Review',
+        ],
+        'published' => [
+          'label' => 'Published',
+        ],
+      ],
+      'transitions' => [
+        'send_to_review' => [
+          'label' => 'Send to review',
+          'from' => ['draft'],
+          'to' => 'review',
+        ],
+        'publish' => [
+          'label' => 'Publish',
+          'from' => ['review'],
+          'to' => 'published',
+        ],
+      ],
+    ];
+    $workflow = new Workflow([], 'test', $plugin_definition, $guard_factory->reveal());
+
+    $transition = $workflow->getTransition('send_to_review');
+    $this->assertEquals($transition, $workflow->findTransition('draft', 'review'));
+    $this->assertNull($workflow->findTransition('foo', 'bar'));
+  }
+
+}

web/modules/state_machine/tests/src/Unit/Plugin/WorkflowGroup/WorkflowGroupTest.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace Drupal\Tests\state_machine\Unit\Plugin\WorkflowGroup;
+
+use Drupal\state_machine\Plugin\Workflow\Workflow;
+use Drupal\state_machine\Plugin\WorkflowGroup\WorkflowGroup;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\state_machine\Plugin\WorkflowGroup\WorkflowGroup
+ * @group state_machine
+ */
+class WorkflowGroupTest extends UnitTestCase {
+
+  /**
+   * The workflow group.
+   *
+   * @var \Drupal\state_machine\Plugin\WorkflowGroup\WorkflowGroup
+   */
+  protected $workflowGroup;
+
+  /**
+   * The plugin definition array.
+   *
+   * @var array
+   */
+  protected $definition = [
+    'id' => 'entity_test',
+    'label' => 'Entity Test',
+    'entity_type' => 'entity_test',
+    'class' => WorkflowGroup::class,
+    'workflow_class' => Workflow::class,
+    'provider' => 'state_machine_test',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+    $this->workflowGroup = new WorkflowGroup([], 'order', $this->definition);
+  }
+
+  /**
+   * @covers ::getId
+   */
+  public function testGetId() {
+    $this->assertEquals($this->definition['id'], $this->workflowGroup->getId());
+  }
+
+  /**
+   * @covers ::getLabel
+   */
+  public function testGetLabel() {
+    $this->assertEquals($this->definition['label'], $this->workflowGroup->getLabel(), 'Workflow group label matches the expected one');
+  }
+
+  /**
+   * @covers ::getEntityTypeId
+   */
+  public function testGetEntityTypeId() {
+    $this->assertEquals($this->definition['entity_type'], $this->workflowGroup->getEntityTypeId(), 'Workflow group entity type id matches the expected one');
+  }
+
+  /**
+   * @covers ::getWorkflowClass
+   */
+  public function testGetWorkflowClass() {
+    $this->assertEquals($this->definition['workflow_class'], $this->workflowGroup->getWorkflowClass(), 'Workflow group class matches the expected one');
+  }
+
+}

web/modules/state_machine/tests/src/Unit/WorkflowManagerCacheTest.php

@@ -0,0 +1,155 @@
+<?php
+
+namespace Drupal\Tests\state_machine\Unit;
+
+use Drupal\Core\Cache\CacheBackendInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\state_machine\Guard\GuardFactoryInterface;
+use Drupal\state_machine\Plugin\Workflow\Workflow;
+use Drupal\state_machine\Plugin\Workflow\WorkflowInterface;
+use Drupal\state_machine\WorkflowGroupManagerInterface;
+use Drupal\state_machine\WorkflowManager;
+use Drupal\Tests\UnitTestCase;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Tests the cache of the workflow manager.
+ *
+ * @coversDefaultClass \Drupal\state_machine\WorkflowManager
+ * @group state_machine
+ */
+class WorkflowManagerCacheTest extends UnitTestCase {
+
+  /**
+   * An instance of the WorkflowManager. This is the system under test.
+   *
+   * @var \Drupal\state_machine\WorkflowManager
+   */
+  protected $workflowManager;
+
+  /**
+   * A mocked instance of the dependency injection container.
+   *
+   * @var \Symfony\Component\DependencyInjection\ContainerInterface|\Prophecy\Prophecy\ObjectProphecy
+   */
+  protected $container;
+
+  /**
+   * A mocked instance of the module handler service.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface|\Prophecy\Prophecy\ObjectProphecy
+   */
+  protected $moduleHandler;
+
+  /**
+   * A mocked instance of a cache backend.
+   *
+   * @var \Drupal\Core\Cache\CacheBackendInterface|\Prophecy\Prophecy\ObjectProphecy
+   */
+  protected $cacheBackend;
+
+  /**
+   * A mocked instance of the workflow group manager.
+   *
+   * @var \Drupal\state_machine\WorkflowGroupManagerInterface|\Prophecy\Prophecy\ObjectProphecy
+   */
+  protected $workflowGroupManager;
+
+  /**
+   * The ID of a mocked workflow plugin used in the test.
+   *
+   * @var string
+   */
+  protected $pluginId = 'test_workflow';
+
+  /**
+   * The ID of a mocked workflow group used in the test.
+   *
+   * @var string
+   */
+  protected $groupId = 'test_group';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->container = $this->prophesize(ContainerInterface::class);
+    \Drupal::setContainer($this->container->reveal());
+    // Mock the dependencies to inject into the workflow manager.
+    $this->moduleHandler = $this->prophesize(ModuleHandlerInterface::class);
+    $this->cacheBackend = $this->prophesize(CacheBackendInterface::class);
+    $this->workflowGroupManager = $this->prophesize(WorkflowGroupManagerInterface::class);
+
+    // Instantiate the workflow manager. This is the system under test.
+    $this->workflowManager = new WorkflowManager(
+      $this->moduleHandler->reveal(),
+      $this->cacheBackend->reveal(),
+      $this->workflowGroupManager->reveal()
+    );
+  }
+
+  /**
+   * Tests that workflow plugins are cached upon creation.
+   *
+   * @covers ::createInstance
+   */
+  public function testCreateInstance() {
+    // In this test we will ask the workflow manager repeatedly for an instance
+    // of a single workflow plugin. Since the manager is supposed to cache the
+    // plugins, it is expected that the GuardFactory (which is a dependency of
+    // the Workflow plugin) is not retrieved more than once from the container.
+    $guard_factory = $this->prophesize(GuardFactoryInterface::class);
+    $this->container->get('state_machine.guard_factory')
+      ->willReturn($guard_factory->reveal())
+      ->shouldBeCalledOnce();
+
+    // It is expected that the workflow manager will retrieve the complete list
+    // of workflows from the cache backend in order to look up the definition of
+    // the workflow plugin that we are creating. Even though we are creating
+    // multiple instances, this should only be called once since the result
+    // should be cached in memory.
+    $this->cacheBackend->get('workflow')
+      ->willReturn((object) [
+        'data' => $this->getMockWorkflowDefinitions(),
+      ])
+      ->shouldBeCalledOnce();
+
+    // Once it found the workflow definition, it is expected that the workflow
+    // group manager will be asked for the definition of the workflow plugin
+    // that is used by the group. The workflow manager requires this data in
+    // order to discover the class name of the workflow plugin so that it can be
+    // instantiated. This too should be called only once.
+    $this->workflowGroupManager->getDefinition($this->groupId)
+      ->willReturn([
+        'workflow_class' => Workflow::class,
+      ])
+      ->shouldBeCalledOnce();
+
+    // Request the same plugin instance multiple times from the workflow
+    // manager. The first instance is cached, and all subsequent invocations
+    // will retrieve the instance from cache.
+    for ($i = 0; $i < 5; $i++) {
+      $plugin = $this->workflowManager->createInstance($this->pluginId);
+      $this->assertInstanceOf(WorkflowInterface::class, $plugin);
+    }
+  }
+
+  /**
+   * Gets a mocked workflow plugin definition.
+   *
+   * @return array
+   *   The mocked workflow definition.
+   */
+  protected function getMockWorkflowDefinitions() {
+    return [
+      'test_workflow' => [
+        'group' => $this->groupId,
+        'states' => [],
+        'transitions' => [],
+      ],
+    ];
+  }
+
+}