Decimal field returning the incorrect string during saving

Change look good. #15 did the manual testing so just reviewing the code

Marking as RBTC but I wonder if

public function providerTestPreSave() { and public function testPreSave($value, $scale, $expected) {

need to be typehinted even though they're test functions

The last submitted patch, 12: 3074419-12.patch, failed testing. View results →

The last submitted patch, 12: 3074419-12.patch, failed testing. View results →

One thing that is interesting about this issue is that the schema and property definitions kinda clash.

  /**
   * {@inheritdoc}
   */
  public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
    $properties['value'] = DataDefinition::create('string')
      ->setLabel(new TranslatableMarkup('Decimal value'))
      ->setRequired(TRUE);

    return $properties;
  }

  /**
   * {@inheritdoc}
   */
  public static function schema(FieldStorageDefinitionInterface $field_definition) {
    return [
      'columns' => [
        'value' => [
          'type' => 'numeric',
          'precision' => $field_definition->getSetting('precision'),
          'scale' => $field_definition->getSetting('scale'),
        ],
      ],
    ];
  }

It really feels like we should have a decimal data type.

Also this change might result in problems for existing code that assume $this->value is set to float during saving so would require a change record.

Regarding #22:

Since 10.2 (see https://www.drupal.org/node/3376447 → ) the decimal data definition is available and used on a DecimalItem.

Is this issue still relevant?