wfUpdatedOn.js

/**
 * @fileoverview Gulp Task for updating wf_updated_on.
 *
 * @author Matt Gaunt
 */

'use strict';

const gulp = require('gulp');
const chalk = require('chalk');
const fse = require('fs-extra');
const moment = require('moment');
const gutil = require('gulp-util');
const wfRegEx = require('./wfRegEx');
const wfHelper = require('./wfHelper');

const MSG_UPDATE = `Updated ${chalk.bold('wf_updated_on')} in`;

/**
 * Gets the list of files that have been staged.
 * @return {Promise<Array<String>>} Returns array of changed Files.
 */
async function getChangedFiles() {
  const cmd = `git diff --name-only --cached`;
  const results = await wfHelper.promisedExec(cmd, '.');
  return results.split('\n');
}

gulp.task('update-updated_on', async () => {
  if (process.env.TRAVIS) {
    // Do nothing on Travis.
    return;
  }

  // List of all files that have changed
  const changedFiles = await getChangedFiles();

  for (const changedFile of changedFiles) {
    if (changedFile.indexOf('src/content') === -1) {
      // File isn't a content file, skip it.
      continue;
    }
    if (!changedFile.endsWith('.md')) {
      // File isn't a Markdown file, skip it.
      continue;
    }
    if (changedFile.indexOf('src/content/en/ilt') >= 0) {
      // File is auto-generated, skip it
      continue;
    }
    try {
      await fse.access(changedFile);
    } catch (err) {
      // File removed
      continue;
    }

    const fileContents = (await fse.readFile(changedFile)).toString();
    if (wfRegEx.RE_AUTO_GENERATED.exec(fileContents)) {
      // File is auto-generated, skip it.
      continue;
    }
    const matched = wfRegEx.RE_UPDATED_ON.exec(fileContents);
    if (!matched) {
      // Updated on not in the file - nothing to do.
      continue;
    }

    const originalUpdatedOn = matched[0];
    const originalTimestamp = matched[1];
    const momentNow = moment();

    if (momentNow.isSameOrBefore(originalTimestamp)) {
      // Updated date is today or in the future.
      continue;
    }

    const newUpdatedOn = originalUpdatedOn
      .replace(originalTimestamp, momentNow.format(`YYYY-MM-DD`));
    const newContents = fileContents.replace(originalUpdatedOn, newUpdatedOn);
    await fse.writeFile(changedFile, newContents);
    // Add the file to the current commit.
    await wfHelper.promisedExec(`git add ${changedFile}`);
    gutil.log(' ', `${MSG_UPDATE} ${chalk.cyan(changedFile)}`);
  }
});