Updated to Gulp 4.0 and now have a task build error

Question

Im updating to Gulp 4.0 but I get an error when running gulp watch, that states: AssertionError [ERR_ASSERTION]: Task never defined: build

The relevant code block in my Gulp file looks like this. What am i doing wrong?

gulp.task('server', gulp.series('build', function () {
browserSync.init(["css/*.css", "js/*.js"], {
    server: { baseDir: "./" , port: 80}
    // If you use vhosts use the line below and comment out the line above.
    //proxy: "demo.local"
});

}));

Answer 1

You have at least this error in your code:

browserSync.init(["css/*.css", "js/*.js"], {

should be:

browserSync({
    files: ["css/*.css", ""js/*.js"]
});

browserSync.init takes an options object as its first argument.

Secondly, the error Task never defined: xxxx I have seen this when, in your case, you call the build task - in your 'server' task before it has been defined/registered. So put the gulp.task('build'...) definition ( a registration of the task) before your 'server' task.

Your gulpfile is erroring for this reason before getting to the other error in browserSync.init mentioned above.