getLastFileId example

    $filename = \Drupal::service('file_system')->tempnam('temporary://', "testManagedFile") . '.txt';
    file_put_contents($filename, $this->randomString(128));
    foreach ([0, 1] as $tree) {
      foreach ([0, 1] as $extended) {
        foreach ([0, 1] as $multiple) {
          $path = 'file/test/' . $tree . '/' . $extended . '/' . $multiple;
          $input_base_name = $tree ? 'nested_file' : 'file';
          $file_field_name = $multiple ? 'files[' . $input_base_name . '][]' : 'files[' . $input_base_name . ']';

          // Now, test the Upload and Remove buttons, with Ajax.           // Upload, then Submit.           $last_fid_prior = $this->getLastFileId();
          $this->drupalGet($path);
          $this->getSession()->getPage()->attachFileToField($file_field_name, $this->container->get('file_system')->realpath($filename));
          $uploaded_file = $this->assertSession()->waitForElement('css', '.file--mime-text-plain');
          $this->assertNotEmpty($uploaded_file);
          $last_fid = $this->getLastFileId();
          $this->assertGreaterThan($last_fid_prior, $last_fid, 'New file got uploaded.');
          $this->submitForm([], 'Save');

          // Remove, then Submit.           $remove_button_title = $multiple ? 'Remove selected' : 'Remove';
          $this->drupalGet($path . '/' . $last_fid);
          

$path = 'file/test/' . $tree . '/' . $extended . '/' . $multiple;
          $input_base_name = $tree ? 'nested_file' : 'file';
          $file_field_name = $multiple ? 'files[' . $input_base_name . '][]' : 'files[' . $input_base_name . ']';

          // Submit without a file.           $this->drupalGet($path);
          $this->submitForm([], 'Save');
          $this->assertSession()->pageTextContains("The file ids are .");

          // Submit with a file, but with an invalid form token. Ensure the file           // was not saved.           $last_fid_prior = $this->getLastFileId();
          $this->drupalGet($path);
          $form_token_field = $this->assertSession()->hiddenFieldExists('form_token');
          $form_token_field->setValue('invalid token');
          $edit = [
            $file_field_name => \Drupal::service('file_system')->realpath($test_file->getFileUri()),
          ];
          $this->submitForm($edit, 'Save');
          $this->assertSession()->pageTextContains('The form has become outdated.');
          $last_fid = $this->getLastFileId();
          $this->assertEquals($last_fid_prior, $last_fid, 'File was not saved when uploaded with an invalid form token.');

          

// Create a default language node.     $default_language_node = $this->drupalCreateNode(['type' => 'basicpage', 'title' => 'Lost in translation']);

    // Edit the node to upload a file.     $edit = [];
    $name = 'files[' . $this->fieldName . '_0]';
    $edit[$name] = \Drupal::service('file_system')->realpath($this->drupalGetTestFiles('image')[0]->uri);
    $this->drupalGet('node/' . $default_language_node->id() . '/edit');
    $this->submitForm($edit, 'Save');
    $edit = [$this->fieldName . '[0][alt]' => 'Lost in translation image', $this->fieldName . '[0][title]' => 'Lost in translation image title'];
    $this->submitForm($edit, 'Save');
    $first_fid = $this->getLastFileId();

    // Translate the node into French: remove the existing file.     $this->drupalGet('node/' . $default_language_node->id() . '/translations/add/en/fr');
    $this->submitForm([], 'Remove');

    // Upload a different file.     $edit = [];
    $edit['title[0][value]'] = 'Scarlett Johansson';
    $name = 'files[' . $this->fieldName . '_0]';
    $edit[$name] = \Drupal::service('file_system')->realpath($this->drupalGetTestFiles('image')[1]->uri);
    $this->submitForm($edit, 'Save (this translation)');
    

$this->assertTrue($definitions[$this->fieldName]->isTranslatable(), 'Node file field is translatable.');

    // Create a default language node.     $default_language_node = $this->drupalCreateNode(['type' => 'page', 'title' => 'Lost in translation']);

    // Edit the node to upload a file.     $edit = [];
    $name = 'files[' . $this->fieldName . '_0]';
    $edit[$name] = \Drupal::service('file_system')->realpath($this->drupalGetTestFiles('text')[0]->uri);
    $this->drupalGet('node/' . $default_language_node->id() . '/edit');
    $this->submitForm($edit, 'Save');
    $first_fid = $this->getLastFileId();

    // Translate the node into French: remove the existing file.     $this->drupalGet('node/' . $default_language_node->id() . '/translations/add/en/fr');
    $this->submitForm([], 'Remove');

    // Upload a different file.     $edit = [];
    $edit['title[0][value]'] = 'Bill Murray';
    $name = 'files[' . $this->fieldName . '_0]';
    $edit[$name] = \Drupal::service('file_system')->realpath($this->drupalGetTestFiles('text')[1]->uri);
    $this->submitForm($edit, 'Save (this translation)');
    

$this->assertTrue($definitions[$this->fieldName]->isTranslatable(), 'Node file field is translatable.');

    // Create a default language node.     $default_language_node = $this->drupalCreateNode(['type' => 'page']);

    // Edit the node to upload a file.     $edit = [];
    $name = 'files[' . $this->fieldName . '_0]';
    $edit[$name] = \Drupal::service('file_system')->realpath($this->drupalGetTestFiles('text')[0]->uri);
    $this->drupalGet('node/' . $default_language_node->id() . '/edit');
    $this->submitForm($edit, 'Save');
    $last_fid_prior = $this->getLastFileId();

    // Languages are cached on many levels, and we need to clear those caches.     $this->rebuildContainer();

    // Ensure the file can be downloaded.     \Drupal::entityTypeManager()->getStorage('node')->resetCache([$default_language_node->id()]);
    $node = Node::load($default_language_node->id());
    $node_file = File::load($node->{$this->fieldName}->target_id);
    $this->drupalGet($node_file->createFileUrl(FALSE));
    $this->assertSession()->statusCodeEquals(200);