gulp 4 - use watch for server job instead of compiler job

Question

If you have a task that starts and finishes, that needs to be run every time files change, that well documented here https://gulpjs.com/docs/en/getting-started/watching-files

const { watch } = require('gulp');

exports.default = function() {
  // The task will be executed upon startup
  watch('src/*.js', { ignoreInitial: false }, function(cb) {
    // body omitted
    cb();
  });
};

But is there a way to use gulp watch like nodemon? Where you leave a task running, and then stop and start it whenever a file on the watchlist is changed?

--- more ---

was asked for some examples, so here are some examples that will not work

the problem is that I don't know how to set it up so that it stops the existing server whenever the watch is triggered.

---- example #1 - run server in process -----

exports.default = function() {
  watch('src/*.js', { ignoreInitial: false }, function(cb) {
    // this will call back but when the watch is triggered again
    // it will try to start another instance
    app.listen(3000, cb);
  });
};

---- example #2 - run server in its own process process -----

exports.default = function() {
  watch('src/*.js', { ignoreInitial: false }, function(cb) {
    const proc = spawn('node', ['server.js']);
    proc.stdout.pipe(process.stdout);
    proc.stderr.pipe(process.stderr);
    // this will never call the call back
    // so never complete
    cb();
  });
};

I don't really understand how your use case differs from a regular watching task in Gulp. Could you add an example? — Lukas Körfer, Jul 09 '19 at 09:01
Did you check out [gulp-nodemon](https://www.npmjs.com/package/gulp-nodemon)? — Lukas Körfer, Jul 09 '19 at 15:36
I have had issues with nodemon, so was trying to find out if there was a simple enough way to do it with just gulp and watch — Alex028502, Jul 09 '19 at 15:37

score 0 · Answer 1 · answered Jul 08 '19 at 20:21

0

Well, at least you can do like that:

% gulp someTask >/dev/null 2>&1 &
[1] _pid_

And your gulp task will run indefinitely if it's a task like watch.

But this approach is very dirty. You should use something like nodemon to achieve that.

answered Jul 08 '19 at 20:21

Alexander Zinchenko

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gulp 4 - use watch for server job instead of compiler job

1 Answers1