Fix the issues reported by phpcs

Assigned to myself, will provide a patch ASAP.

Thanks

Please review this patch. Thanks.

 /**
  * @file
- * Contains gravitas_countdown.module.
+ * Hook implementations for gravitas_countdown module.
  */

The usual module description is Hook implementations for the [module name] module. where [module name] is replaced by the module name shown in the .info.yml file.

+ * Get previous image ids of the countdown.
+ *
+ * @param string $countdown_data_config
+ *   The configuration data for the countdown.
+ *
+ * @return array
+ *   An array of previous image IDs.
  */
-function get_countdown_description_images($countdown_data_config)
-{
-  $image_ids = array();
+function get_countdown_description_images($countdown_data_config) {

Since that documentation comment is edited:

• The verb used in the description must use the third person singular
• ids is misspelled and it must be corrected
• Assuming that the description is about countdown images, a better description would be Gets the previous countdown image IDs.

 /**
- * form alter block_delete_form to delete the images used
- * on the block
- * @param  [type]             &$form
- * @param  FormStateInterface $form_state
- * @return [type]
+ * Implements Form alter block_delete_form.
+ *
+ * To delete the images used on the block.
+ *
+ * @param array &$form
+ *   The form being altered.
+ * @param \Drupal\Core\Form\FormStateInterface $form_state
+ *   The current state of the form.
  */
-function gravitas_countdown_form_alter(&$form, FormStateInterface $form_state)
-{
+function gravitas_countdown_form_alter(array &$form, FormStateInterface $form_state) {

Since that is a hook implementation, the documentation comment is shorter.
The description is not correct.

-    // get block entity
+    // Get block entity.
     if ($block_entity) {

A definite article is missing in the comment.

-      // check if the plugin id is gravitas_countdown
+      // Check if the plugin id is gravitas_countdown.
       if ($block_plugin_id == 'gravitas_countdown') {

That comment is not necessary, since it describes something that is clear from the code.

 /**
- * submit form callback to remove the images used
- * on the countdown block
- * @param  [type]             $form
- * @param  FormStateInterface $form_state
- * @return [type]
+ * Submit form callback.
+ *
+ * To remove the images used on the countdown block.
+ *
+ * @param array $form
+ *   The form being submitted.
+ * @param \Drupal\Core\Form\FormStateInterface $form_state
+ *   The current state of the form.
  */
-function gravitas_countdown_form_submit($form, FormStateInterface $form_state)
-{
+function gravitas_countdown_form_submit(array $form, FormStateInterface $form_state) {

Since that is a form submission handler, its documentation comment is different.
The hook description must make clear to which form the submission handler is added, which is usually done by using the form ID.

+ * @return array
+ *   An array of file IDs used in the countdown editor.
  */
-function get_countdown_editor_files($content)

It is not necessary to repeat the return value type, in the return value description.

 /**
-* Implements theme_mymodule_thumb_upload theme callback.
-*/
+ * Implements theme_mymodule_thumb_upload theme callback.
+ */
 function theme_mymodule_thumb_upload($variables) {

 /**
-* Implements theme_mymodule_thumb_upload theme callback.
-*/
+ * Implements theme_mymodule_thumb_upload theme callback.
+ */
 function theme_mymodule_thumb_upload($variables) {

Not considering that Drupal 8/9/10 do not have anymore theme implementations, the documentation comment for theme implementations is different. It is like the following one, for example.

/**
 * Returns HTML for a select form element.
 *
 * It is possible to group options together; to do this, change the format of
 * $options to an associative array in which the keys are group labels, and the
 * values are associative arrays in the normal $options format.
 *
 * @param $variables
 *   An associative array containing:
 *   - element: An associative array containing the properties of the element.
 *     Properties used: #title, #value, #options, #description, #extra,
 *     #multiple, #required, #name, #attributes, #size.
 *
 * @ingroup themeable
 */
function theme_select($variables) {
  $element = $variables['element'];
  element_set_attributes($element, array('id', 'name', 'size'));
  _form_set_class($element, array('form-select'));
  return '<select' . drupal_attributes($element['#attributes']) . '>' . form_select_options($element) . '</select>';
}

-  // The remove button is already taken care of by rendering the rest of the form. No need to hack up some HTML!
+  // The remove button is already taken care of
+  // by rendering the rest of the form.
+  // No need to hack up some HTML!

Avoiding that lines exceed 80 characters does not mean making them too short.

+            var counter = setInterval(function () {
+                var now = new Date().getTime();
+                var daysInnerText, hoursInnerText, minutesInnerText, secondsInnerText;
+                var distance = countDown - now;
+                if(distance < 0) {

The lines after the first are not correctly indented.
There must be a space between if and the next parenthesis.

Hi,

I modified the patch accordingly, please review.

Also, @apaderno, for the point where you gave feedback for:

+            var counter = setInterval(function () <strong>{</strong>
+                var now = new Date().getTime();
+                var daysInnerText, hoursInnerText, minutesInnerText, secondsInnerText;
+                var distance = countDown - now;
+                if(distance < 0) {

The lines after the first are not correctly indented.
There must be a space between if and the next parenthesis.

It is important to note that all the lines in the code are properly indented. There might have been some confusion due to the initial lines starting with "var" and the curly brace not being clearly visible. Such confusions can happen, and I appreciate your understanding. Nevertheless, I have made the necessary changes as requested in the rest of the code. Thank you for bringing the rest of the issues to my attention.

Indentation in JavaScript files is two spaces. That means that each time the indentation is increased, it is increased of two spaces, not four.
The fact the previous line starts a function does not change that. Otherwise, Drupal core will not format the following code as it does.

      $row.find('.js-real-checkbox').each(function () {
        this.style.display = authCheckbox.checked ? 'none' : '';
      });
      $row.find('.js-dummy-checkbox').each(function () {
        this.style.display = authCheckbox.checked ? '' : 'none';
      });

Formatted the file with two space indentation.

 /**
  * @file
- * Contains gravitas_countdown.module.
+ * Hook implementations for Gravitas Countdown module.
  */

The description is missing a definite article after for.

 /**
- * form alter block_delete_form to delete the images used
- * on the block
- * @param  [type]             &$form
- * @param  FormStateInterface $form_state
- * @return [type]
+ * Implements hook_form_alter().
+ *
+ * Hook used to delete the images used on the block.
  */
-function gravitas_countdown_form_alter(&$form, FormStateInterface $form_state)
-{
+function gravitas_countdown_form_alter(array &$form, FormStateInterface $form_state) {

For hook implementations, the description starts with Implements followed by the hook name.

+ * Removes the images used on the countdown block
+ * after the block_delete_form form submission.
+ * This submission handler, gravitas_countdown_form_submit,
+ * is added to the block_delete_form form
+ * when the block entity's plugin ID is 'gravitas_countdown'.
+ *
+ * @param array $form
+ *   The form being submitted.
+ * @param \Drupal\Core\Form\FormStateInterface $form_state
+ *   The current state of the form.
  */
-function gravitas_countdown_form_submit($form, FormStateInterface $form_state)
-{
+function gravitas_countdown_form_submit(array $form, FormStateInterface $form_state) {

The documentation comment for form submission handlers is different from the documentation comments for other functions. API documentation and comment standards / Form-generating functions → shows an example of documentation comment for a form validation handler and a forum submission handler.

 /**
- * @param $content
+ * Retrieves the file IDs associated with the countdown editor content.
+ *
+ * @param string $content
+ *   The content of the countdown editor.
+ *
  * @throws \Drupal\Core\Entity\EntityStorageException
+ *   If there is an error loading the file entities.
+ *
+ * @return array
+ *   An array of file IDs used in the countdown editor.
  */

As per Drupal API documentation standards for order of documentation sections → , the @throws line must be after the @return line.
@throws: Thrown exceptions → says:

Drupal standards notes: The name of an exception class should appear on the same line as the @throws tag. Put explanations in starting on the next line, but only if they tell you something useful that is not conveyed by the name of the class. If you include an explanation, like other documentation use complete sentences that stand alone, without assuming that "Throws [exception name]" is part of the sentence automatically, since Throws will be a heading when it's displayed on api.drupal.org.

-* Implements theme_mymodule_thumb_upload theme callback.
-*/
+ * Theme function for rendering the thumbnail upload element.
+ *
+ * Renders the HTML output for the thumbnail upload element,
+ * including the image preview and additional widget data.
+ */
 function theme_mymodule_thumb_upload($variables) {

The (short) description must be a single line and not exceed 80 characters (with the usual exceptions).
As shown in Themeable functions → , the parameter must be described.

/**
 * Returns HTML for a foo.
 *
 * @param array $variables
 *   An associative array containing:
 *   - foo: The foo object that is being formatted.
 *   - show_bar: TRUE to show the bar component, FALSE to omit it.
 *
 * @ingroup themeable
 */
function theme_foo($variables) {

   // My uploaded element didn't have a preview array item, so this didn't work
-  //if (isset($element['preview'])) {
-  //  $output .= '<div class="image-preview">';
-  //  $output .= drupal_render($element['preview']);
-  //  $output .= '</div>';
-  //}
-
-  // If image is uploaded show its thumbnail to the output HTML
+  // if (isset($element['preview'])) {
+  // $output .= '<div class="image-preview">';
+  // $output .= drupal_render($element['preview']);
+  // $output .= '</div>';
+  // }

Even for commented out code, the indentation must be preserved. The existing code is the following one.

  // My uploaded element didn't have a preview array item, so this didn't work
  //if (isset($element['preview'])) {
  //  $output .= '<div class="image-preview">';
  //  $output .= drupal_render($element['preview']);
  //  $output .= '</div>';
  //}

It is correct to add a space after the comment delimiter, but the lines inside the if control statement must be indented two spaces more compared to if.

  // My uploaded element didn't have a preview array item, so this didn't work
  // if (isset($element['preview'])) {
  //   $output .= '<div class="image-preview">';
  //   $output .= drupal_render($element['preview']);
  //   $output .= '</div>';
  // }

There must be a space between if and the parenthesis.

+        } else {
+          daysInnerText = Math.floor(distance / (day));
+          hoursInnerText = Math.floor((distance % (day)) / (hour));
+          minutesInnerText = Math.floor((distance % (hour)) / (minute)); secondsInnerText = Math.floor((distance % (minute)) / second);
+        }

As shown in Control Structures → else is put on its own line.
secondsInnerText = Math.floor((distance % (minute)) / second); must be on a new line.

-    $description = $values['description_settings']['description'] ?? '';
-    $old_countdown_image_ids = array();
-    $current_countdown_image_ids = array();
-
+    // $description = $values['description_settings']['description'] ?? '';
+    // $old_countdown_image_ids = [];
+    // $current_countdown_image_ids = [];

Code lines that must be deleted, are not commented out.

-      $file->setPermanent();
+      /* Load the object of the file by it's fid */
+      $file = File::load($image_fid);

Inside methods or functions, the used comment delimiter is //. it's is a misspelling for its, the possessive pronoun for it. the object of the file should be the file object.
I would rather remove that comment, as it is not necessary for $file = File::load($image_fid); which is already clear by itself.

Updated the patch.

As per #9:

The description is missing a definite article after for.

The word "for" is added.

/**
- * form alter block_delete_form to delete the images used
- * on the block
- * @param  [type]             &$form
- * @param  FormStateInterface $form_state
- * @return [type]
+ * Implements hook_form_alter().
+ *
+ * Hook used to delete the images used on the block.
  */
-function gravitas_countdown_form_alter(&$form, FormStateInterface $form_state)
-{
+function gravitas_countdown_form_alter(array &$form, FormStateInterface $form_state) {

For hook implementations, the description starts with Implements followed by the hook name.

The description is appropriate and starts with "Implements" followed by hook name i.e. hook_form_alter.

+ * Removes the images used on the countdown block
+ * after the block_delete_form form submission.
+ * This submission handler, gravitas_countdown_form_submit,
+ * is added to the block_delete_form form
+ * when the block entity's plugin ID is 'gravitas_countdown'.
+ *
+ * @param array $form
+ *   The form being submitted.
+ * @param \Drupal\Core\Form\FormStateInterface $form_state
+ *   The current state of the form.
  */
-function gravitas_countdown_form_submit($form, FormStateInterface $form_state)
-{
+function gravitas_countdown_form_submit(array $form, FormStateInterface $form_state) {

The documentation comment for form submission handlers is different from the documentation comments for other functions. API documentation and comment standards / Form-generating functions shows an example of documentation comment for a form validation handler and a forum submission handler.

Standard first line comment is added, the rest is general description of the submission handler

 /**
- * @param $content
+ * Retrieves the file IDs associated with the countdown editor content.
+ *
+ * @param string $content
+ *   The content of the countdown editor.
+ *
  * @throws \Drupal\Core\Entity\EntityStorageException
+ *   If there is an error loading the file entities.
+ *
+ * @return array
+ *   An array of file IDs used in the countdown editor.
  */

As per Drupal API documentation standards for order of documentation sections, the @throws line must be after the @return line.
@throws: Thrown exceptions says:

Drupal standards notes: The name of an exception class should appear on the same line as the @throws tag. Put explanations in starting on the next line, but only if they tell you something useful that is not conveyed by the name of the class. If you include an explanation, like other documentation use complete sentences that stand alone, without assuming that "Throws [exception name]" is part of the sentence automatically, since Throws will be a heading when it's displayed on api.drupal.org.

Repositioned @throws tag after @return.

-* Implements theme_mymodule_thumb_upload theme callback.
-*/
+ * Theme function for rendering the thumbnail upload element.
+ *
+ * Renders the HTML output for the thumbnail upload element,
+ * including the image preview and additional widget data.
+ */
 function theme_mymodule_thumb_upload($variables) {

The (short) description must be a single line and not exceed 80 characters (with the usual exceptions).
As shown in Themeable functions, the parameter must be described.

Reverted the original description added by maintainer, the rest information explains the functionality.

   // My uploaded element didn't have a preview array item, so this didn't work
-  //if (isset($element['preview'])) {
-  //  $output .= '<div class="image-preview">';
-  //  $output .= drupal_render($element['preview']);
-  //  $output .= '</div>';
-  //}
-
-  // If image is uploaded show its thumbnail to the output HTML
+  // if (isset($element['preview'])) {
+  // $output .= '<div class="image-preview">';
+  // $output .= drupal_render($element['preview']);
+  // $output .= '</div>';
+  // }

Even for commented out code, the indentation must be preserved.
It is correct to add a space after the comment delimiter, but the lines inside the if control statement must be indented two spaces more compared to if.

Space is added for the lines under "if".

// My uploaded element didn't have a preview array item, so this didn't work
  // if (isset($element['preview'])) {
  //   $output .= '<div class="image-preview">';
  //   $output .= drupal_render($element['preview']);
  //   $output .= '</div>';
  // }

There must be a space between if and the parenthesis.

Unsure of this, as I can see space between "if" and parenthesis. Can you please elaborate this?

+        } else {
+          daysInnerText = Math.floor(distance / (day));
+          hoursInnerText = Math.floor((distance % (day)) / (hour));
+          minutesInnerText = Math.floor((distance % (hour)) / (minute)); secondsInnerText = Math.floor((distance % (minute)) / second);
+        }

As shown in Control Structures else is put on its own line.
secondsInnerText = Math.floor((distance % (minute)) / second); must be on a new line.

Moved "else" to a new line and also the "secondsInnerText = Math.floor((distance % (minute)) / second);".

-    $description = $values['description_settings']['description'] ?? '';
-    $old_countdown_image_ids = array();
-    $current_countdown_image_ids = array();
-
+    // $description = $values['description_settings']['description'] ?? '';
+    // $old_countdown_image_ids = [];
+    // $current_countdown_image_ids = [];

Code lines that must be deleted, are not commented out.

No, I can't delete these lines as the module is under active development and these variables are unused variables as of now, but the maintainer might need it, thus commented them to meet the coding standards requirement. However, before removing them, we should ask for the maintainer's permission.

-      $file->setPermanent();
+      /* Load the object of the file by it's fid */
+      $file = File::load($image_fid);

Inside methods or functions, the used comment delimiter is //. it's is a misspelling for its, the possessive pronoun for it. the object of the file should be the file object.
I would rather remove that comment, as it is not necessary for $file = File::load($image_fid); which is already clear by itself.

Removed the comment.

Do let me know, if you have any more suggestions. Thanks

 /**
- * form alter block_delete_form to delete the images used
- * on the block
- * @param  [type]             &$form
- * @param  FormStateInterface $form_state
- * @return [type]
+ * Implements hook_form_alter().
+ *
+ * Hook used to delete the images used on the block.
  */
-function gravitas_countdown_form_alter(&$form, FormStateInterface $form_state)
-{
+function gravitas_countdown_form_alter(array &$form, FormStateInterface $form_state) {
   if ($form['#form_id'] == 'block_delete_form') {

Only the short description is used for hook implementations. In the case of hook_form_alter() implementation, the short description must say which form is altered. (That is shown in the last line I quoted.)

- * submit form callback to remove the images used
- * on the countdown block
- * @param  [type]             $form
- * @param  FormStateInterface $form_state
- * @return [type]
+ * Form submission handler for block_delete_form().
+ *
+ * Removes the images used on the countdown block
+ * after the block_delete_form form submission.
+ * This submission handler, gravitas_countdown_form_submit,
+ * is added to the block_delete_form form
+ * when the block entity's plugin ID is 'gravitas_countdown'.
+ *
+ * @param array $form
+ *   The form being submitted.
+ * @param \Drupal\Core\Form\FormStateInterface $form_state
+ *   The current state of the form.
  */
-function gravitas_countdown_form_submit($form, FormStateInterface $form_state)
-{
+function gravitas_countdown_form_submit(array $form, FormStateInterface $form_state) {

The short description is correct, except Drupal 8 and higher versions do not implement block_delete_form(). It is better to use the form ID, block_delete_form, already used from the module code.
The longer description is not used for form submission handlers.
Parameter descriptions are not given for form submission handlers.

 /**
-* Implements theme_mymodule_thumb_upload theme callback.
-*/
-function theme_mymodule_thumb_upload($variables) {
+ * Implements theme_mymodule_thumb_upload theme callback.
+ *
+ * Renders the HTML output for the thumbnail upload element,
+ * including the image preview and additional widget data.
+ * 
+ * @param array $variables
+ *   An associative array
+ */
+function theme_mymodule_thumb_upload(array $variables) {

The correct documentation comment for a theme function is similar to the following one.

/**
 * Returns HTML for a foo.
 *
 * @param array $variables
 *   An associative array containing:
 *   - foo: The foo object that is being formatted.
 *   - show_bar: TRUE to show the bar component, FALSE to omit it.
 *
 * @ingroup themeable
 */
function theme_foo($variables) {

The @ingroup line is optional.

+    // $output .= theme('image_style',
+    // array(
+    //   'style_name' => 'thumbnail',
+    //   'path' => file_load($element['fid']['#value'])->uri,
+    //   'getsize' => FALSE
+    // ));.

Periods are not added to commented out code. phpcs does not parse comments to understand it is commented out code.

coding-standard-fixes-10.patch. This patch was applied cleanly on 1.1.0. But, there were few dependency injection issues which were not handled.
Please find updated patch with all changes.

HI @bharath-kondeti the patch #13 it applied cleanly. No more phpcs errors/warnings are produced.
I ran phpcs --standard=Drupal,DrupalPractice --extensions=php,module,inc,install,test,profile,theme,css,info,txt,md,yml,js . to test.

Thanks!