eleventy-plugin-git-commit-date/src/getCollectionNewestGitCommitDate.js

Eleventy plugin to get Git commit time of a file, or a Eleventy collection.

// @ts-check
const getGitCommitDateFromPath = require("./getGitCommitDateFromPath");

/**
 * Gets the collection's newest Git commit date.
 *
 * @param      {Array<object>}  collection  The collection
 *
 * @return     {Date}           The collection newest git commit date.
 */
module.exports = function (collection) {
  if (!collection || !collection.length) {
    return;
  }

  const timestamps = collection
    .map((item) => getGitCommitDateFromPath(item.inputPath))
    // Timestamps will be undefined for the paths not
    // yet commited to Git. So weeding them out.
    .filter((ts) => Boolean(ts))
    .map((ts) => ts.getTime());

  if (timestamps.length) {
    return new Date(Math.max(...timestamps));
  }
};