Google Doc Word Count for list of URLs in a sheet

/* The ID of the Google Sheet that you want to write the word count to. */
const SHEET_ID = "SheetIDGoesHere";

/**
 * It gets the URLs of Google Docs from column A of the first sheet in a Google Sheet, then it gets the
 * word count of each Google Doc and writes it to column B of the same row as the URL.
 */
function countWords() {
  /* Get the Google Sheet. */
  const sheet = SpreadsheetApp.openById(SHEET_ID);

  /* It gets the first sheet in the Google Sheet and gets the values of column A, filtering out the
  empty rows. */
  const firstSheet = sheet.getSheets()[0];
  const urlValues = firstSheet
    .getRange("A2:A")
    .getValues()
    .filter((row) => row[0]);

  /* Converting the 2D array `urlValues` into a 1D array `urls`. */
  const urls = [].concat(...urlValues);
  let wordCounts = [];

  /* Getting the URLs of Google Docs from column A of the first sheet in a Google Sheet, then it gets
  the word count of each Google Doc and writes it to column B of the same row as the URL. */
  for (const url of urls) {
    /* Getting the document ID from the URL. */
    const documentId = url.match(/[-\w]{25,}/);

    /* Opening the Google Doc with the ID `documentId`. */
    const document = DocumentApp.openById(documentId);

    /* Initializing the variable `wordCount` to 0. */
    let wordCount = 0;

    /* Config for the headings and titles in the document to be excluded them from the word count.
    This is the same functionality that Google Docs uses for wordcount */
    const searchType = DocumentApp.ElementType.PARAGRAPH;
    const searchHeadings = [
      DocumentApp.ParagraphHeading.HEADING1,
      DocumentApp.ParagraphHeading.HEADING2,
      DocumentApp.ParagraphHeading.HEADING3,
      DocumentApp.ParagraphHeading.HEADING4,
      DocumentApp.ParagraphHeading.HEADING5,
      DocumentApp.ParagraphHeading.HEADING6,
      DocumentApp.ParagraphHeading.TITLE
    ];
    let searchResult = null;

    /* Getting the headings and titles in the document to be excluded them from the word count.
    This is the same functionality that Google Docs uses for wordcount. */
    while (
      (searchResult = document.getBody().findElement(searchType, searchResult))
    ) {
      const par = searchResult.getElement().asParagraph();
      if (searchHeadings.includes(par.getHeading())) {
        /* Subtracting the word count of the heading from the total word count. */
        wordCount -= par.getText().split(" ").length;
      }
    }

    /* It gets the paragraphs in the document. */
    const paragraphs = document.getBody().getParagraphs();

    /* Getting an individual paragraph from all the paragraphs and counting its words. */
    for (const paragraph of paragraphs) {
      /* It gets the text of the paragraph. */
      const paragraphText = paragraph.getText();

      /* Getting the word count of the paragraph and adding it to the total word count. */
      wordCount += paragraphText.split(" ").length;
    }
    /* Pushing the word count of the Google Doc to the array `wordCounts`. */
    wordCounts.push([wordCount]);
  }

  /* Writing the word count to Column B of the same row as the URL. */
  firstSheet
    .getRange(`B2:B${(wordCounts.length + 1).toString()}`)
    .setValues(wordCounts);
}