index.js

const fs = require('fs');
const pathModule = require('path');
const chokidar = require('chokidar');
const texturePacker = require('free-tex-packer-core');
const appInfo = require('./package.json');

const SUPPORTED_EXT = ['png', 'jpg', 'jpeg'];

function isFolder(path) {
    if (isExists(path)) {
        return fs.statSync(path).isDirectory();
    }
    else {
        path = fixPath(path);
        let name = getNameFromPath(path);
        let parts = name.split('.');
        return parts.length === 1;
    }
}

function isExists(path) {
    return fs.existsSync(path);
}

function fixPath(path) {
    return path.trim().split('\\').join('/');
}

function getNameFromPath(path) {
    return path.trim().split('/').pop();
}

function getExtFromPath(path) {
    return path.trim().split('.').pop().toLowerCase();
}

function getFolderFilesList(dir, base = '', list = []) {
    let files = fs.readdirSync(dir);
    for (let file of files) {
        let path = pathModule.resolve(dir, file);
        if (isFolder(path) && path.toUpperCase().indexOf('__MACOSX') < 0) {
            list = getFolderFilesList(path, base + file + '/', list);
        }
        else {
            list.push({
                name: (base ? base : '') + file,
                path: path
            });
        }
    }

    return list;
}

function getSubFoldersList(dir, list = []) {
    let files = fs.readdirSync(dir);
    for (let file of files) {
        let path = pathModule.resolve(dir, file);
        if (isFolder(path) && path.toUpperCase().indexOf('__MACOSX') < 0) {
            list.push(path);
            list = getSubFoldersList(path, list);
        }
    }

    return list;
}

class WebpackFreeTexPacker {
    constructor(src, dest = '.', options = {}) {
        if (!Array.isArray(src)) src = [src];

        this.src = src;
        this.dest = dest;

        this.options = options;
        this.options.appInfo = appInfo;

        this.changed = true;

        this.watcher = null;
        this.watchStarted = false;

        this.onFsChanges = this.onFsChanges.bind(this);
    }

    addDependencie(dependencies, path) {
        if (Array.isArray(dependencies)) dependencies.push(path);
        else dependencies.add(path);

        this.addToWatch(path);
    }

    addToWatch(path) {
        if (!this.watcher) {
            this.watcher = chokidar.watch(path, { ignoreInitial: true });
            this.watcher.on('all', this.onFsChanges);
        }
        else {
            this.watcher.add(path);
        }
    }

    onFsChanges() {
        this.changed = true;
    }

    apply(compiler) {
        if (compiler.hooks && compiler.hooks.emit) {
            // Webpack 4
            compiler.hooks.emit.tapAsync('WebpackFreeTexPacker', this.emitHookHandler.bind(this));
        } else {
            // Webpack 3
            compiler.plugin('emit', this.emitHookHandler.bind(this))
        }
    }

    emitHookHandler(compilation, callback) {
        let files = {};

        let devMode = (!compilation.options || compilation.options.mode === 'development');

        for (let srcPath of this.src) {
            let path = fixPath(srcPath);

            let name = getNameFromPath(path);

            if (name === '.' || name === '*' || name === '*.*') {
                srcPath = srcPath.substr(0, srcPath.length - name.length - 1);
                path = fixPath(srcPath);
                name = '';
            }

            if (isFolder(path)) {
                if (isExists(srcPath)) {
                    let list = getFolderFilesList(path, (name ? name + '/' : ''));
                    for (let file of list) {
                        let ext = getExtFromPath(file.path);
                        if (SUPPORTED_EXT.indexOf(ext) >= 0) files[file.name] = file.path;
                    }
                }

                if (devMode) this.addDependencie(compilation.contextDependencies, srcPath);

                let subFolders = getSubFoldersList(srcPath);
                for (let folder of subFolders) {
                    if (devMode) this.addDependencie(compilation.contextDependencies, folder);
                }
            }
            else {
                if (isExists(srcPath)) {
                    files[getNameFromPath(path)] = path;
                }

                if (devMode) this.addDependencie(compilation.fileDependencies, srcPath);
            }
        }

        if (this.watchStarted && !this.changed) {
            callback();
            return;
        }

        let images = [];
        let names = Object.keys(files);
        for (let name of names) {
            images.push({ path: name, contents: fs.readFileSync(files[name]) });
        }

        texturePacker(images, this.options, (files) => {
            for (let item of files) {
                (function (item, dest) {
                    compilation.assets[dest + '/' + item.name] = {
                        source: function () {
                            return item.buffer;
                        },
                        size: function () {
                            return item.buffer.length;
                        }
                    };
                })(item, this.dest);
            }
            callback();
        });

        this.changed = false;
        this.watchStarted = true;
    }
}

module.exports = WebpackFreeTexPacker;