Passing a flag from a gulp series? - gulp

Question

I can run a task with a flag via:
gulp build --production
Is there anyway to have a task set up like this:
gulp.task('deploy',
gulp.series('build'));
And also include the flag:
gulp.task('deploy',
gulp.series('build --production'));
So I could just call gulp deploy to run a production build?

Answer 1

Since this is not really possible using the built-in gulp functionality, I wrote a package that makes this as easy and convenient as possible: gulp-parameterized.
(Note: this is still a work in progress. For one thing it needs a comprehensive test suite. It's also severely lacking in documentation. However the core functionality has been tested and should work.)
Here's your example using gulp-parameterized:
var gulp = require('gulp');
var parameterized = require('gulp-parameterized');
gulp.task('build', parameterized(function(_) {
if (_.params.production) {
/* production build */
} else {
/* development build */
}
}));
gulp.task('deploy', parameterized.series('build --production'));
This also automatically parses command line flags, so you don't need to parse those yourself with yargs anymore.
The following commands create production builds:
$ gulp build --production
$ gulp deploy
While the following commands create development builds:
$ gulp build
$ gulp build --no-production