Gulpfile.js generator

gulpfile-generator.js

// ----------------------------------------------------------
// module imports

// const { existsSync, mkdirSync, readFileSync, writeFileSync } = require('fs');
// const { execSync } = require('child_process');

// ----------------------------------------------------------
// parse commandline arguments

const argv = require('yargs')
	.boolean('html')
	.alias('s', 'style').alias('css', 'style')
	// .alias('t', 'templates')
	.boolean('babel')
	.boolean('react')
	.boolean('server')
	.boolean('webdev').alias('w', 'webdev')
	.boolean('concat').alias('c', 'concat')
	.boolean('concat')
	.alias('c', 'concat')
	.argv;

// console.log(argv);


// ----------------------------------------------------------
// interpret commandline arguments

// default project directory to current directory
argv.path = argv._[0] || '.';

// the webdev argument forces style and templates
if (argv.webdev) {
	argv.style = argv.style || 'css';
	argv.html = true;
	// argv.templates = argv.templates || 'templates';
}

// react compilation requires babel
argv.babel = argv.babel || argv.react;


// ----------------------------------------------------------
// calculate the gulp tasks to build

var tasks = [];

if (argv.html) {

	let task = { 
		name: 'html',
		dest: 'public',
		src: 'src/*.html'
	};
	tasks.push(task);

}

if (argv.style) {

	let task = { name: 'css', dest: 'public' };
	tasks.push(task);

	switch (argv.style) {

		case 'sass':
			task.src = 'src/*.sass';
			task.package = 'gulp-sass';
			task.processor = 'sass';
			break;
		case 'scss':
			task.src = 'src/*.scss';
			task.package = 'gulp-sass';
			task.processor = 'sass';
			break;
		case 'less':
			task.src = 'src/*.less';
			task.package = 'gulp-less';
			task.processor = 'less';
			break;
		case 'stylus':
			task.src = 'src/*.stylus';
			task.package = 'gulp-stylus';
			task.processor = 'stylus';
			break;
		case 'css':
			task.src = 'src/*.css';
			break;
	}
}

if (argv.babel) {

	let task = { 
		name: 'js', 
		dest: 'public', 
		src: 'src/*.js',
		package: 'gulp-babel',
		processor: 'babel'
	};
	tasks.push(task);

	if (argv.react) {
		task.options = '{presets: ["@babel/preset-react","@babel/preset-env"]}';
	} else {
		task.options = '{presets: ["@babel/preset-env"]}';
	}

}

if (argv.server) {

	let task = { 
		name: 'webserver',
		src: 'public',
		package: 'gulp-webserver',
		processor: 'webserver',
		options: '{livereload: true}'
	};
	tasks.push(task);

}


// ----------------------------------------------------------
// generate gulpfile

var output = [];
output.push("var gulp = require('gulp');");

for (let task of tasks) {
	if (task.processor) {
		output.push(`var ${ task.processor } = require('${ task.package }');`);
	}
}
output.push('');

for (let task of tasks) {
	output.push(`gulp.task('${ task.name }', function(){`);
	output.push(`\treturn gulp.src('${ task.src }')`);
	if (task.processor) {
		output.push(`\t\t.pipe(${task.processor}(${ task.options || '' }))`);
	}
	if (task.dest) {
		output.push(`\t\t.pipe(gulp.dest('${ task.dest }'))`);
	}
	output.push('});')
	output.push('');
}

output = output.join('\n');
console.log(output);


// ----------------------------------------------------------
// create project directory and write gulpfile

/*
if (argv.path !== '.') {

	let path = argv.path;
	
	if (!existsSync(argv.path)) {
		mkdirSync(path);
	}

	process.chdir(path);

}

console.log('writing gulpfile.js');
writeFileSync('gulpfile.js', output, 'utf8');
*/