diff -u b/core/modules/content_moderation/content_moderation.info.yml b/core/modules/content_moderation/content_moderation.info.yml
--- b/core/modules/content_moderation/content_moderation.info.yml
+++ b/core/modules/content_moderation/content_moderation.info.yml
@@ -9 +9 @@
-  - workflow
\ No newline at end of file
+  - workflow
diff -u b/core/modules/workflow/src/Form/WorkflowDeleteForm.php b/core/modules/workflow/src/Form/WorkflowDeleteForm.php
--- b/core/modules/workflow/src/Form/WorkflowDeleteForm.php
+++ b/core/modules/workflow/src/Form/WorkflowDeleteForm.php
@@ -15,7 +15,7 @@
    * {@inheritdoc}
    */
   public function getQuestion() {
-    return $this->t('Are you sure you want to delete %name?', array('%name' => $this->entity->label()));
+    return $this->t('Are you sure you want to delete %name?', ['%name' => $this->entity->label()]);
   }
 
   /**
diff -u b/core/modules/workflow/src/Form/WorkflowEditForm.php b/core/modules/workflow/src/Form/WorkflowEditForm.php
--- b/core/modules/workflow/src/Form/WorkflowEditForm.php
+++ b/core/modules/workflow/src/Form/WorkflowEditForm.php
@@ -44,41 +44,41 @@
       'weight' => $this->t('Weight'),
       'operations' => $this->t('Operations')
     ];
-    $form['states_container'] = array(
+    $form['states_container'] = [
       '#type' => 'details',
       '#title' => $this->t('States'),
       '#open' => TRUE,
       '#collapsible' => 'FALSE',
-    );
+    ];
     $form['states_container']['description'] = [
       '#prefix' => '<p>',
       '#markup' => $this->t('@todo describe what a state is.'),
       '#suffix' => '</p>',
     ];
-    $form['states_container']['states'] = array(
+    $form['states_container']['states'] = [
       '#type' => 'table',
       '#header' => $header,
       '#title' => $this->t('States'),
       '#empty' => $this->t('There are no states yet.'),
-      '#tabledrag' => array(
-        array(
+      '#tabledrag' => [
+        [
           'action' => 'order',
           'relationship' => 'sibling',
           'group' => 'state-weight',
-        ),
-      ),
-    );
+        ],
+      ],
+    ];
     foreach ($workflow->getStates() as $state) {
       $links['edit'] = [
         'title' => $this->t('Edit'),
         'url' => Url::fromRoute('entity.workflow.edit_state_form', ['workflow' => $workflow->id(), 'workflow_state' => $state->id()]),
         'attributes' => ['aria-label' => $this->t('Edit @state state', ['@state' => $state->label()])],
       ];
-      $links['delete'] = array(
+      $links['delete'] = [
         'title' => t('Delete'),
         'url' => Url::fromRoute('entity.workflow.delete_state_form', ['workflow' => $workflow->id(), 'workflow_state' => $state->id()]),
         'attributes' => ['aria-label' => $this->t('Delete @state state', ['@state' => $state->label()])],
-      );
+      ];
       $form['states_container']['states'][$state->id()] = [
         '#attributes' => ['class' => ['draggable']],
         'state' => ['#markup' => $state->label()],
@@ -96,9 +96,9 @@
         ],
       ];
     }
-    $form['states_container']['state_add'] = array(
+    $form['states_container']['state_add'] = [
       '#markup' => $workflow->toLink($this->t('Add a new state'), 'add-state-form')->toString(),
-    );
+    ];
 
     $header = [
       'state' => $this->t('From'),
@@ -106,33 +106,33 @@
       'label' => $this->t('Label'),
       'operations' => $this->t('Operations')
     ];
-    $form['transitions_container'] = array(
+    $form['transitions_container'] = [
       '#type' => 'details',
       '#title' => $this->t('Transitions'),
       '#open' => TRUE,
-    );
+    ];
     $form['transitions_container']['description'] = [
       '#prefix' => '<p>',
       '#markup' => $this->t('@todo describe what a transition is.'),
       '#suffix' => '</p>',
     ];
-    $form['transitions_container']['transitions'] = array(
+    $form['transitions_container']['transitions'] = [
       '#type' => 'table',
       '#header' => $header,
       '#title' => $this->t('Transitions'),
       '#empty' => $this->t('There are no transitions yet.'),
-    );
+    ];
     foreach ($workflow->getTransitions() as $transition) {
       $links['edit'] = [
         'title' => $this->t('Edit'),
         'url' => Url::fromRoute('entity.workflow.edit_transition_form', ['workflow' => $workflow->id(), 'workflow_transition' => $transition->id()]),
         'attributes' => ['aria-label' => $this->t('Edit transition from @from_state to @to_state', ['@from_state' => $transition->from()->label(), '@to_state' => $transition->to()->label()])],
       ];
-      $links['delete'] = array(
+      $links['delete'] = [
         'title' => t('Delete'),
         'url' => Url::fromRoute('entity.workflow.delete_transition_form', ['workflow' => $workflow->id(), 'workflow_transition' => $transition->id()]),
         'attributes' => ['aria-label' => $this->t('Delete transition from @from_state to @to_state', ['@from_state' => $transition->from()->label(), '@to_state' => $transition->to()->label()])],
-      );
+      ];
       $form['transitions_container']['transitions'][$transition->id()] = [
         'to' => ['#markup' => $transition->from()->label()],
         'from' => ['#markup' => $transition->to()->label()],
@@ -143,9 +143,9 @@
         ],
       ];
     }
-    $form['transitions_container']['transition_add'] = array(
+    $form['transitions_container']['transition_add'] = [
       '#markup' => $workflow->toLink($this->t('Add a new transition'), 'add-transition-form')->toString(),
-    );
+    ];
 
     return $form;
   }
diff -u b/core/modules/workflow/src/Form/WorkflowStateAddForm.php b/core/modules/workflow/src/Form/WorkflowStateAddForm.php
--- b/core/modules/workflow/src/Form/WorkflowStateAddForm.php
+++ b/core/modules/workflow/src/Form/WorkflowStateAddForm.php
@@ -19,29 +19,29 @@
 
     /* @var \Drupal\workflow\WorkflowInterface $workflow */
     $workflow = $this->getEntity();
-    $form['label'] = array(
+    $form['label'] = [
       '#type' => 'textfield',
       '#title' => $this->t('Label'),
       '#maxlength' => 255,
       '#default_value' => '',
       '#description' => $this->t('Label for the state.'),
       '#required' => TRUE,
-    );
+    ];
 
-    $form['id'] = array(
+    $form['id'] = [
       '#type' => 'machine_name',
-      '#machine_name' => array(
+      '#machine_name' => [
         'exists' => [$this, 'exists'],
-      ),
-    );
+      ],
+    ];
 
-    $form['transition_to_self_label'] = array(
+    $form['transition_to_self_label'] = [
       '#type' => 'textfield',
       '#title' => $this->t('Label'),
       '#maxlength' => 255,
       '#default_value' => '',
       '#description' => $this->t('Label for the transition to self. If this is left blank a transition will not be created.'),
-    );
+    ];
 
     // Add additional form fields from the workflow type plugin.
     $form['type_settings'] = [
@@ -115,11 +115,11 @@
    * {@inheritdoc}
    */
   protected function actions(array $form, FormStateInterface $form_state) {
-    $actions['submit'] = array(
+    $actions['submit'] = [
       '#type' => 'submit',
       '#value' => $this->t('Save'),
-      '#submit' => array('::submitForm', '::save'),
-    );
+      '#submit' => ['::submitForm', '::save'],
+    ];
     return $actions;
   }
 
diff -u b/core/modules/workflow/src/Form/WorkflowStateDeleteForm.php b/core/modules/workflow/src/Form/WorkflowStateDeleteForm.php
--- b/core/modules/workflow/src/Form/WorkflowStateDeleteForm.php
+++ b/core/modules/workflow/src/Form/WorkflowStateDeleteForm.php
@@ -37,7 +37,7 @@
    * {@inheritdoc}
    */
   public function getQuestion() {
-    return $this->t('Are you sure you want to delete %state from %workflow?', array('%state' => $this->workflow->getState($this->stateId)->label(), '%workflow' => $this->workflow->label()));
+    return $this->t('Are you sure you want to delete %state from %workflow?', ['%state' => $this->workflow->getState($this->stateId)->label(), '%workflow' => $this->workflow->label()]);
   }
 
   /**
diff -u b/core/modules/workflow/src/Form/WorkflowStateEditForm.php b/core/modules/workflow/src/Form/WorkflowStateEditForm.php
--- b/core/modules/workflow/src/Form/WorkflowStateEditForm.php
+++ b/core/modules/workflow/src/Form/WorkflowStateEditForm.php
@@ -36,23 +36,23 @@
     /* @var \Drupal\workflow\WorkflowInterface $workflow */
     $workflow = $this->getEntity();
     $state = $workflow->getState($this->stateId);
-    $form['label'] = array(
+    $form['label'] = [
       '#type' => 'textfield',
       '#title' => $this->t('Label'),
       '#maxlength' => 255,
       '#default_value' => $state->label(),
       '#description' => $this->t('Label for the state.'),
       '#required' => TRUE,
-    );
+    ];
 
-    $form['id'] = array(
+    $form['id'] = [
       '#type' => 'machine_name',
       '#default_value' => $this->stateId,
-      '#machine_name' => array(
+      '#machine_name' => [
         'exists' => [$this, 'exists'],
-      ),
+      ],
       '#disabled' => TRUE,
-    );
+    ];
 
     // Add additional form fields from the workflow type plugin.
     $form['type_settings'] = [
@@ -78,13 +78,13 @@
           'workflow_transition' => $transition->id()
         ]),
       ];
-      $links['delete'] = array(
+      $links['delete'] = [
         'title' => t('Delete'),
         'url' => Url::fromRoute('entity.workflow.delete_transition_form', [
           'workflow' => $workflow->id(),
           'workflow_transition' => $transition->id()
         ]),
-      );
+      ];
       $form['transitions'][$transition->id()] = [
         'label' => [
           '#markup' => $transition->label(),
@@ -142,25 +142,25 @@
    * {@inheritdoc}
    */
   protected function actions(array $form, FormStateInterface $form_state) {
-    $actions['submit'] = array(
+    $actions['submit'] = [
       '#type' => 'submit',
       '#value' => $this->t('Save'),
-      '#submit' => array('::submitForm', '::save'),
-    );
+      '#submit' => ['::submitForm', '::save'],
+    ];
 
-    $actions['delete'] = array(
+    $actions['delete'] = [
       '#type' => 'link',
       '#title' => $this->t('Delete'),
       // Deleting a state is editing a workflow.
       '#access' => $this->entity->access('edit'),
-      '#attributes' => array(
-        'class' => array('button', 'button--danger'),
-      ),
+      '#attributes' => [
+        'class' => ['button', 'button--danger'],
+      ],
       '#url' => Url::fromRoute('entity.workflow.delete_state_form', [
         'workflow' => $this->entity->id(),
         'workflow_state' => $this->stateId
       ])
-    );
+    ];
 
     return $actions;
   }
diff -u b/core/modules/workflow/src/Form/WorkflowTransitionAddForm.php b/core/modules/workflow/src/Form/WorkflowTransitionAddForm.php
--- b/core/modules/workflow/src/Form/WorkflowTransitionAddForm.php
+++ b/core/modules/workflow/src/Form/WorkflowTransitionAddForm.php
@@ -20,14 +20,14 @@
 
     /* @var \Drupal\workflow\WorkflowInterface $workflow */
     $workflow = $this->getEntity();
-    $form['label'] = array(
+    $form['label'] = [
       '#type' => 'textfield',
       '#title' => $this->t('Label'),
       '#maxlength' => 255,
       '#default_value' => '',
       '#description' => $this->t('Label for the transition.'),
       '#required' => TRUE,
-    );
+    ];
 
     // @todo add some ajax to ensure that only valid transitions are selectable.
     $states = array_map([State::class, 'labelCallback'], $workflow->getStates());
@@ -122,11 +122,11 @@
    * {@inheritdoc}
    */
   protected function actions(array $form, FormStateInterface $form_state) {
-    $actions['submit'] = array(
+    $actions['submit'] = [
       '#type' => 'submit',
       '#value' => $this->t('Save'),
-      '#submit' => array('::submitForm', '::save'),
-    );
+      '#submit' => ['::submitForm', '::save'],
+    ];
     return $actions;
   }
 
diff -u b/core/modules/workflow/src/Form/WorkflowTransitionDeleteForm.php b/core/modules/workflow/src/Form/WorkflowTransitionDeleteForm.php
--- b/core/modules/workflow/src/Form/WorkflowTransitionDeleteForm.php
+++ b/core/modules/workflow/src/Form/WorkflowTransitionDeleteForm.php
@@ -44,7 +44,7 @@
    * {@inheritdoc}
    */
   public function getQuestion() {
-    return $this->t('Are you sure you want to delete the transition from %from to %to from %workflow?', array('%from' => $this->transition->from()->label(), '%to' => $this->transition->to()->label(), '%workflow' => $this->workflow->label()));
+    return $this->t('Are you sure you want to delete the transition from %from to %to from %workflow?', ['%from' => $this->transition->from()->label(), '%to' => $this->transition->to()->label(), '%workflow' => $this->workflow->label()]);
   }
 
   /**
diff -u b/core/modules/workflow/src/Form/WorkflowTransitionEditForm.php b/core/modules/workflow/src/Form/WorkflowTransitionEditForm.php
--- b/core/modules/workflow/src/Form/WorkflowTransitionEditForm.php
+++ b/core/modules/workflow/src/Form/WorkflowTransitionEditForm.php
@@ -37,14 +37,14 @@
     /* @var \Drupal\workflow\WorkflowInterface $workflow */
     $workflow = $this->getEntity();
     $transition = $workflow->getTransition($this->transitionId);
-    $form['label'] = array(
+    $form['label'] = [
       '#type' => 'textfield',
       '#title' => $this->t('Label'),
       '#maxlength' => 255,
       '#default_value' => $transition->label(),
       '#description' => $this->t('Label for the transition.'),
       '#required' => TRUE,
-    );
+    ];
 
     $form['id'] = [
       '#type' => 'hidden',
@@ -121,25 +121,25 @@
    * {@inheritdoc}
    */
   protected function actions(array $form, FormStateInterface $form_state) {
-    $actions['submit'] = array(
+    $actions['submit'] = [
       '#type' => 'submit',
       '#value' => $this->t('Save'),
-      '#submit' => array('::submitForm', '::save'),
-    );
+      '#submit' => ['::submitForm', '::save'],
+    ];
 
-    $actions['delete'] = array(
+    $actions['delete'] = [
       '#type' => 'link',
       '#title' => $this->t('Delete'),
       // Deleting a transition is editing a workflow.
       '#access' => $this->entity->access('edit'),
-      '#attributes' => array(
-        'class' => array('button', 'button--danger'),
-      ),
+      '#attributes' => [
+        'class' => ['button', 'button--danger'],
+      ],
       '#url' => Url::fromRoute('entity.workflow.delete_transition_form', [
         'workflow' => $this->entity->id(),
         'workflow_transition' => $this->transitionId
       ])
-    );
+    ];
 
     return $actions;
   }
diff -u b/core/modules/workflow/tests/src/Unit/StateTest.php b/core/modules/workflow/tests/src/Unit/StateTest.php
--- b/core/modules/workflow/tests/src/Unit/StateTest.php
+++ b/core/modules/workflow/tests/src/Unit/StateTest.php
@@ -5,6 +5,8 @@
 use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Tests\UnitTestCase;
 use Drupal\workflow\Entity\Workflow;
+use Drupal\workflow\State;
+use Drupal\workflow\WorkflowInterface;
 use Drupal\workflow\WorkflowTypeInterface;
 use Drupal\workflow\WorkflowTypeManager;
 use Prophecy\Argument;
@@ -36,6 +38,24 @@
   }
 
   /**
+   * @covers ::__construct
+   * @covers ::id
+   * @covers ::label
+   * @covers ::weight
+   */
+  public function testGetters() {
+    $state = new State(
+      $this->prophesize(WorkflowInterface::class)->reveal(),
+      'draft',
+      'Draft',
+      3
+    );
+    $this->assertEquals('draft', $state->id());
+    $this->assertEquals('Draft', $state->label());
+    $this->assertEquals(3, $state->weight());
+  }
+
+  /**
    * @covers ::canTransitionTo
    */
   public function testCanTransitionTo() {
@@ -54,9 +74,6 @@
 
   /**
    * @covers ::getTransitionTo
-   * @covers \Drupal\workflow\Transition::from
-   * @covers \Drupal\workflow\Transition::to
-   * @covers \Drupal\workflow\Transition::label
    */
   public function testGetTransitionTo() {
     $workflow = new Workflow(['id' => 'test', 'type' => 'test_type'], 'workflow');
@@ -66,8 +83,6 @@
       ->addTransition('draft', 'published', 'Publish');
     $state = $workflow->getState('draft');
     $transition = $state->getTransitionTo('published');
-    $this->assertEquals($state, $transition->from());
-    $this->assertEquals($workflow->getState('published'), $transition->to());
     $this->assertEquals('Publish', $transition->label());
   }
 
@@ -84,8 +99,6 @@
 
   /**
    * @covers ::getTransitions
-   * @covers \Drupal\workflow\Transition::from
-   * @covers \Drupal\workflow\Transition::to
    */
   public function testGetTransitions() {
     $workflow = new Workflow(['id' => 'test', 'type' => 'test_type'], 'workflow');
@@ -99,10 +112,20 @@
     $state = $workflow->getState('draft');
     $transitions = $state->getTransitions();
     $this->assertCount(2, $transitions);
-    $this->assertEquals('draft', $transitions['draft-draft']->from()->id());
-    $this->assertEquals('draft', $transitions['draft-draft']->to()->id());
-    $this->assertEquals('draft', $transitions['draft-published']->from()->id());
-    $this->assertEquals('published', $transitions['draft-published']->to()->id());
+    $this->assertEquals('Create new draft', $transitions['draft-draft']->label());
+    $this->assertEquals('Publish', $transitions['draft-published']->label());
+  }
+
+  /**
+   * @covers ::labelCallback
+   */
+  public function testLabelCallback() {
+    $workflow = $this->prophesize(WorkflowInterface::class)->reveal();
+    $states = [
+      new State($workflow, 'draft', 'Draft'),
+      new State($workflow, 'published', 'Published'),
+    ];
+    $this->assertEquals(['Draft', 'Published'], array_map([State::class, 'labelCallback'], $states));
   }
 
 }
diff -u b/core/modules/workflow/tests/src/Unit/WorkflowTest.php b/core/modules/workflow/tests/src/Unit/WorkflowTest.php
--- b/core/modules/workflow/tests/src/Unit/WorkflowTest.php
+++ b/core/modules/workflow/tests/src/Unit/WorkflowTest.php
@@ -18,6 +18,9 @@
  */
 class WorkflowTest extends UnitTestCase {
 
+  /**
+   * {@inheritdoc}
+   */
   protected function setUp() {
     parent::setUp();
     // Create a container so that the plugin manager and workflow type can be
@@ -339,7 +342,7 @@
 
 
   /**
-   * @covers ::getState
+   * @covers ::getTransition
    */
   public function testGetTransition() {
     $workflow = new Workflow(['id' => 'test', 'type' => 'test_type'], 'workflow');
@@ -362,7 +365,7 @@
   }
 
   /**
-   * @covers ::getState
+   * @covers ::getTransition
    */
   public function testGetTransitionException() {
     $this->setExpectedException(\InvalidArgumentException::class, "The transition 'transition_that_does_not_exist' does not exist in workflow 'test'");
@@ -371,6 +374,52 @@
   }
 
   /**
+   * @covers ::getTransitionsForState
+   */
+  public function testGetTransitionsForState() {
+    $workflow = new Workflow(['id' => 'test', 'type' => 'test_type'], 'workflow');
+    // By default states are ordered in the order added.
+    $workflow
+      ->addState('draft', 'Draft')
+      ->addState('published', 'Published')
+      ->addState('archived', 'Archived')
+      ->addTransition('draft', 'draft', 'Create new draft')
+      ->addTransition('draft', 'published', 'Publish')
+      ->addTransition('published', 'published', 'Publish')
+      ->addTransition('published', 'archived', 'Archive')
+      ->addTransition('archived', 'draft', 'Create new draft');
+
+    $this->assertEquals(['draft-draft', 'draft-published'], array_keys($workflow->getTransitionsForState('draft')));
+    $this->assertEquals(['draft-draft', 'archived-draft'], array_keys($workflow->getTransitionsForState('draft', 'to')));
+    $this->assertEquals(['archived-draft'], array_keys($workflow->getTransitionsForState('archived', 'from')));
+    $this->assertEquals(['published-archived'], array_keys($workflow->getTransitionsForState('archived', 'to')));
+  }
+
+
+  /**
+   * @covers ::getTransitionFromStateToState
+   * @covers ::hasTransitionFromStateToState
+   */
+  public function testGetTransitionsFromStateToState() {
+    $workflow = new Workflow(['id' => 'test', 'type' => 'test_type'], 'workflow');
+    // By default states are ordered in the order added.
+    $workflow
+      ->addState('draft', 'Draft')
+      ->addState('published', 'Published')
+      ->addState('archived', 'Archived')
+      ->addTransition('draft', 'draft', 'Create new draft')
+      ->addTransition('draft', 'published', 'Publish')
+      ->addTransition('published', 'published', 'Publish')
+      ->addTransition('published', 'archived', 'Archive')
+      ->addTransition('archived', 'draft', 'Create new draft');
+
+    $this->assertTrue($workflow->hasTransitionFromStateToState('draft', 'published'));
+    $this->assertFalse($workflow->hasTransitionFromStateToState('archived', 'archived'));
+    $transition = $workflow->getTransitionFromStateToState('published', 'archived');
+    $this->assertEquals('Archive', $transition->label());
+  }
+
+  /**
    * @covers ::setTransitionLabel
    */
   public function testSetTransitionLabel() {
only in patch2:
unchanged:
--- /dev/null
+++ b/core/modules/workflow/tests/src/Unit/TransitionTest.php
@@ -0,0 +1,71 @@
+<?php
+
+namespace Drupal\Tests\workflow\Unit;
+
+use Drupal\Core\DependencyInjection\ContainerBuilder;
+use Drupal\Tests\UnitTestCase;
+use Drupal\workflow\Entity\Workflow;
+use Drupal\workflow\Transition;
+use Drupal\workflow\WorkflowInterface;
+use Drupal\workflow\WorkflowTypeInterface;
+use Drupal\workflow\WorkflowTypeManager;
+use Prophecy\Argument;
+
+/**
+ * @coversDefaultClass \Drupal\workflow\Transition
+ *
+ * @group workflow
+ */
+class TransitionTest extends UnitTestCase {
+
+  /**
+   * Sets up the Workflow Type manager so that workflow entities can be used.
+   */
+  protected function setUp() {
+    parent::setUp();
+    // Create a container so that the plugin manager and workflow type can be
+    // mocked.
+    $container = new ContainerBuilder();
+    $workflow_type = $this->prophesize(WorkflowTypeInterface::class);
+    $workflow_type->decorateState(Argument::any())->willReturnArgument(0);
+    $workflow_type->decorateTransition(Argument::any())->willReturnArgument(0);
+    $workflow_manager = $this->prophesize(WorkflowTypeManager::class);
+    $workflow_manager->createInstance('test_type', Argument::any())->willReturn($workflow_type->reveal());
+    $container->set('workflow.plugin.manager.workflow_type', $workflow_manager->reveal());
+    \Drupal::setContainer($container);
+  }
+
+  /**
+   * @covers ::__construct
+   * @covers ::id
+   * @covers ::label
+   */
+  public function testGetters() {
+    $state = new Transition(
+      $this->prophesize(WorkflowInterface::class)->reveal(),
+      'draft-published',
+      'draft',
+      'published',
+      'Publish'
+    );
+    $this->assertEquals('draft-published', $state->id());
+    $this->assertEquals('Publish', $state->label());
+  }
+
+  /**
+   * @covers ::from
+   * @covers ::to
+   */
+  public function testFromAndTo() {
+    $workflow = new Workflow(['id' => 'test', 'type' => 'test_type'], 'workflow');
+    $workflow
+      ->addState('draft', 'Draft')
+      ->addState('published', 'Published')
+      ->addTransition('draft', 'published', 'Publish');
+    $state = $workflow->getState('draft');
+    $transition = $state->getTransitionTo('published');
+    $this->assertEquals($state, $transition->from());
+    $this->assertEquals($workflow->getState('published'), $transition->to());
+  }
+
+}