Use gulp files from other npm packages (import files which will eventually exist)

Question

I have one npm package containing several files with several gulp task definitions.

What I want is in the main gulpfile, be able to copy these gulp files (from the package) and execute the gulp tasks defined in them.

Follows an example:

const gulp = require('gulp');
const fs = require('fs');
const path = require('path');

const gulpFolder = path.join(__dirname.replace('gulpfile.js', ''), 'src', 'generated-code', 'gulp'); 

const cleanGulpFiles = (callback) => { ... }

const copyGulpFiles = (callback) => {
    gulp.src(`${nodeModulesFolder}/@primavera/client-app-core/gulp/**/*`)
        .pipe(chmod(666))
        .pipe(gulp.dest(gulpFolder));
    callback();
}

exports.debug = gulp.series(
    cleanGulpFiles, 
    copyGulpFiles,
    require('../src/generated-code/gulp/gulp.debug'));

The problem is: When I try to execute gulp debug, it is retrieved an error saying require('../src/generated-code/gulp/gulp.debug') does not exists. And it is right because this file will be only available when the task copyGulpFiles is done.

Anyone knows a workaround to do what I want to accomplish?

Answer 1

The only workaround that I found was to combine fs.readFileSync and eval functions in order to read the gulp file content as a string and then evaluate that code in run time:

const gulp = require('gulp');
const fs = require('fs');
const path = require('path');

const gulpFolder = path.join(__dirname.replace('gulpfile.js', ''), 'src', 'generated-code', 'gulp'); 

const cleanGulpFiles = (callback) => { ... }

const copyGulpFiles = (callback) => {
    gulp.src(`${nodeModulesFolder}/@primavera/client-app-core/gulp/**/*`)
        .pipe(chmod(666))
        .pipe(gulp.dest(gulpFolder));
    callback();
}

const executeGulpFiles = (callback) => {
    const fileContent = fs.readFileSync('../src/generated-code/gulp/gulp.debug');
    const contentEvaluated = eval(fileContent);
    contentEvaluated(callback);
}

exports.debug = gulp.series(
    cleanGulpFiles, 
    copyGulpFiles,
    executeGulpFiles);