Quelques essais nodejs rapport à https://n.survol.fr/n/resoudre-le-callback-hell-javascript-102

4- promise.js

const program = require('commander')
const glob = require('glob')
const path = require('path')
const jsonfile = require('jsonfile')
const sizeOf = require('image-size')

program
    .version("1.0.0")
    .arguments('<manifest> <dir>')
    .action(writeFilesDimensions)
    .parse(process.argv);

function writeFilesDimensions(manifest, dir) {
    const source_path = path.join(dir, "**/*.png");
    const options = {};

    glob(source_path, options, function(err, files) {
        if(err) return error(err);
        Promise.all(files.map(getFileDimensionData))
            .then(data => writeManifest(manifest, data))
            .then(result => console.info("SUCCESS!"))
            .catch(err => error(err));
    });
}

function error(err) {
    console.error("ERROR: %s", err.message);
}

function writeManifest(manifest, data) {
    return new Promise(function(resolve, reject) {
        jsonfile.writeFile(manifest, data, function(err, result) {
            if (err) return reject(err);
            return resolve(result);
        });
    });
}

function getFileDimensionData(file) {
    return new Promise(function(resolve, reject) {
        sizeOf(file, function(err, dimensions) {
            if (err) return reject(err);
            dimensions.path = file;
            dimensions.name = path.basename(file);
            return resolve(dimensions);
        })
    });
}

if (process.argv.length < 3) {
    program.outputHelp();
    exit(1);
}