Hide shipping cost dollar amount when shipping cost equals $0?

Automatically closed - issue fixed for 2 weeks with no activity.

FYI for anyone trying to do this in D10 I copied the existing field formatter and added some logic to remove the price if it's 0.

Then you must enable the new formatter in: Commerce > Config > Shipping > Shipment Types > Manage form display (checkout)

src/Plugin/Field/FieldWidget/YOUR_MODULEShippingRateWidget.php

<?php

namespace Drupal\YOUR_MODULE\Plugin\Field\FieldWidget;

use Drupal\commerce_checkout\Plugin\Commerce\CheckoutFlow\CheckoutFlowWithPanesInterface;
use Drupal\commerce_shipping\Plugin\Field\FieldWidget\ShippingRateWidget;
use Drupal\Component\Render\FormattableMarkup;
use Drupal\Component\Utility\NestedArray;
use Drupal\Core\Field\FieldDefinitionInterface;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Form\FormStateInterface;

/**
 * Plugin implementation of the 'commerce_shipping_rate' widget.
 *
 * @FieldWidget(
 *   id = "your_module_shipping_rate",
 *   label = @Translation("YOUR_MODULE Shipping Rate (0 removal)"),
 *   field_types = {
 *     "entity_reference"
 *   }
 * )
 */
class YOUR_MODULEShippingRateWidget extends ShippingRateWidget {

  /**
   * {@inheritdoc}
   */
  public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state) {
    /** @var \Drupal\commerce_shipping\Entity\ShipmentInterface $shipment */
    $shipment = $items[$delta]->getEntity();
    $parents = array_merge($form['#parents'], [$this->fieldDefinition->getName(), 0]);
    $rates_key = implode('_', $parents);
    // Store the calculated rates in form state to avoid repeated calculations.
    if (!$form_state->has($rates_key) || $form_state->get('recalculate_shipping')) {
      $form_state->set($rates_key, $this->shipmentManager->calculateRates($shipment));
    }
    $rates = $form_state->get($rates_key);
    if (!$rates) {
      // When there are no rates available for this address, clear the selected rate.
      $shipment->clearRate();
      $element = [
        '#markup' => $this->t('There are no shipping rates available for this address.'),
      ];
      return $element;
    }

    $default_rate = $this->shipmentManager->selectDefaultRate($shipment, $rates);
    // If we're in checkout, attach an AJAX callback to refresh the order summary.
    if ($form_state->getFormObject() instanceof CheckoutFlowWithPanesInterface) {
      $element['#ajax'] = [
        'callback' => [get_called_class(), 'ajaxRefreshForm'],
      ];

      $parents = array_merge($form['#parents'], [$this->fieldDefinition->getName(), 0]);
      $user_input = (array) NestedArray::getValue($form_state->getUserInput(), $parents);
      // Apply the default rate if no rate is selected.
      if (empty($user_input)) {
        $this->shipmentManager->applyRate($shipment, $default_rate);
      }
    }

    $element['#type'] = 'radios';
    $element['#default_value'] = $default_rate->getId();
    $element['#options'] = [];
    foreach ($rates as $rate_id => $rate) {
      $amount = $rate->getAmount();
      $pre_promotion_amount = $rate->getPrePromotionAmount();

      // If the shipping amount is 0.00, display only the service label.
      if (floatval($amount->getNumber()) == 0) {
        $rate_label = new FormattableMarkup('@service', [
          '@service' => $rate->getService()->getLabel(),
        ]);
      }
      else {
        if ($pre_promotion_amount && $pre_promotion_amount->greaterThan($amount)) {
          $rate_label = new FormattableMarkup('@service: <s>@original_amount</s> @amount', [
            '@service' => $rate->getService()->getLabel(),
            '@original_amount' => $this->currencyFormatter->format($pre_promotion_amount->getNumber(), $pre_promotion_amount->getCurrencyCode()),
            '@amount' => $this->currencyFormatter->format($amount->getNumber(), $amount->getCurrencyCode()),
          ]);
        }
        else {
          $rate_label = new FormattableMarkup('@service: @amount', [
            '@service' => $rate->getService()->getLabel(),
            '@amount' => $this->currencyFormatter->format($amount->getNumber(), $amount->getCurrencyCode()),
          ]);
        }
      }
      $element['#options'][$rate_id] = $rate_label;
      $element[$rate_id]['#description'] = $rate->getDescription();
      // Prevent Bootstrap (if used) from converting the description into a tooltip.
      $element[$rate_id]['#smart_description'] = FALSE;
      // Store the rate object for use in extractFormValues().
      $element[$rate_id]['#rate'] = $rate;
    }

    return $element;
  }

}