Function parseExtensionFlags

build-system/tasks/extension-helpers.js:217–273

* Parses the --extensions, --extensions_from, and the --noextensions flags, * and prints a helpful message that lets the developer know how to (pre)build * the runtime with a list of extensions, all the extensions used by a test * file, or no extensions at all. * @param {boolean=} preBuild

(preBuild = false)

 * @param {boolean=} preBuild
 */
function parseExtensionFlags(preBuild = false) {
  if (isCiBuild()) {
    return;
  }

  const buildOrPreBuild = preBuild ? 'pre-build' : 'build';
  const coreRuntimeOnlyMessage =
    green('⤷ Use ') +
    cyan('--core_runtime_only ') +
    green('to build just the core runtime and skip other JS targets.');
  const noExtensionsMessage =
    green('⤷ Use ') +
    cyan('--noextensions ') +
    green('to skip building extensions.');
  const extensionsMessage =
    green('⤷ Use ') +
    cyan('--extensions=amp-foo,amp-bar ') +
    green(`to choose which extensions to ${buildOrPreBuild}.`);
  const inaboxSetMessage =
    green('⤷ Use ') +
    cyan('--extensions=inabox ') +
    green(`to ${buildOrPreBuild} just the extensions needed to load AMP ads.`);
  const extensionsFromMessage =
    green('⤷ Use ') +
    cyan('--extensions_from=examples/foo.amp.html ') +
    green(`to ${buildOrPreBuild} just the extensions needed to load `) +
    cyan('foo.amp.html') +
    green('.');

  if (argv.core_runtime_only && !(argv.extensions || argv.extensions_from)) {
    log(green('Building just the core runtime.'));
  } else if (preBuild) {
    log(
      green('Pre-building extension(s):'),
      cyan(getExtensionsToBuild(preBuild).join(', '))
    );
    log(extensionsMessage);
    log(inaboxSetMessage);
    log(extensionsFromMessage);
  } else {
    if (argv.noextensions) {
      log(green('Not building any AMP extensions.'));
    } else if (argv.extensions || argv.extensions_from) {
      log(
        green('Building extension(s):'),
        cyan(getExtensionsToBuild().join(', '))
      );
    } else {
      log(green('Building all AMP extensions.'));
    }
    log(coreRuntimeOnlyMessage);
    log(noExtensionsMessage);
    log(extensionsMessage);
    log(inaboxSetMessage);
    log(extensionsFromMessage);
  }
}