Generate an entry point suitable for using Ember.js with rollup

ember-register.js

#!/usr/bin/env node
"use strict";
/* Copyright (C) 2017 Julien Hartmann, juli1.hartmann@gmail.com
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

/* The program requires the template compiler from Ember to be available
 * in a "deps" subdirectory. Or just edit the path below.
 *
 * Run as ./ember-register.js config-file.ini myproject.main.js
 *
 * Sample configuration file attached in the gist.
 */

const assert = require('assert');
const compiler = require('./deps/ember-template-compiler.js');
const fs = require('fs');
const path = require('path');
const process = require('process');

/****************************************************************************/

function parseArgs(argv) {
    var config = {
        input: null,
        output: null,
        includes: []
    };
    var opt = null;

    function addOption(option, value) {
        switch (option) {
        case 'I':
            config.includes.push(value);
            break;
        case null:
            if (!config.input) { config.input = value; break; }
            if (!config.output) { config.output = value; break; }
            throw new Error("Syntax: ember-register [options] input [output]");
        }
    }

    for (var idx = 2; idx < argv.length; ++idx) {
        const token = argv[idx];
        if (token[0] === '-' && token.length >= 2) {
            if (token.length > 2) {
                addOption(token[1], token.substr(2));
            } else {
                opt = token[1];
            }
        } else if (opt) {
            addOption(opt, token);
            opt = null;
        } else {
            addOption(null, token);
        }
    }

    if (!config.input) { throw new Error("Requires an input argument"); }
    if (!config.output) { config.output = '-'; }
    config.includes.unshift(path.dirname(config.input));
    return config;
}

function parseConfig(filePath) {
    const ini = require('ini');
    const conf = ini.parse(fs.readFileSync(filePath, 'utf-8'));
    const registrations = conf.registrations || {};

    var register = {};
    conf.register.split(',').forEach(function (name) {
        name = name.trim();

        var dirname = name + 's';
        var options = {};

        if (registrations.hasOwnProperty(name)) {
            registrations[name].split(" ").forEach(function (str) {
                var option = str.split(':');
                options[option[0]] = option[1];
            });
        }
        if (options.dirname) {
            dirname = options.dirname;
            delete options.dirname;
        }
        register[name] = {
            name: name,
            dirname: dirname,
            options: options
        };
    });

    return {
        globals: conf.globals || {},
        register: register,
        roots: conf.roots || [],
        imports: conf.imports || []
    };
}

/****************************************************************************/

function findPath(filePath, locations) {
    if (path.isAbsolute(filePath)) {
        if (fs.existsSync(path)) { return attempt; }
        throw new Error(`File not found: ${filePath}`);
    }

    for (var idx = 0; idx < locations.length; ++idx) {
        const attempt = path.join(locations[idx], filePath);
        if (fs.existsSync(attempt)) { return attempt; }
    }
    throw new Error(`File not found: ${filePath} -- searched in ${locations}`);
}

function readdir(dirPath) {
    return new Promise((resolve, reject) => {
        fs.readdir(dirPath, (err, files) => {
            if (err) { reject(err); } else { resolve(files); }
        });
    });
}

function walkPath(dirPath, callback) {
    return readdir(dirPath).then(files => {
        return Promise.all(files.map(function (fileName) {
            return walkPath(path.join(dirPath, fileName), callback);
        }));
    }, error => {
        if (error.code === "ENOTDIR") { callback(dirPath); return; }
        throw error;
    });
}

function camelize(str) {
    return str.replace(/(?!^)[_-]([a-zA-Z])/, (match, p1) => { return p1.toUpperCase(); });
}

/****************************************************************************/

class Generator {
    constructor (config) {
        this.tplExtensions = ['.tpl', '.hbs'];
        this.typesByDirname = {};
        this.typesByName = {};
        this.suffixes = ['.js'].concat(this.tplExtensions);

        for (var key in config.register) { if (config.register.hasOwnProperty(key)) {
            const entry = config.register[key];
            this.typesByName[entry.name] = entry;
            this.typesByDirname[entry.dirname] = entry;
        }}

        this.initializers = [];
        this.registrations = [];
        this.templates = [];
    }

    // Drop one suffix from the list, if present
    removeSuffix(str, suffixes) {
        for (var idx = 0; idx < suffixes.length; ++idx) {
            if (str.endsWith(suffixes[idx])) {
                return str.substr(0, str.length - suffixes[idx].length);
            }
        }
        return str;
    }

    // Convert a file path into a token list, handling extensions
    tokenizePath(path) {
        var tokens = path.split('/');
        tokens = tokens.filter(token => { return token; });

        tokens[tokens.length - 1] = this.removeSuffix(
            tokens[tokens.length - 1], this.suffixes
        );
        return tokens;
    }

    makeRegistrationName(tokens) {
        return tokens.map(camelize).join('.');
    }

    // Compile a template file. Returns a promise that resolves to template code.
    compileTemplate(filePath) {
        var data = fs.readFileSync(filePath, 'utf-8');
        return compiler.precompile(data.toString(), false);
    }

    // Handle a single file
    handleFile(filePath, root) {
        assert(!root || filePath.startsWith(root));

        const tokens = this.tokenizePath(root ? filePath.substr(root.length) : filePath);
        const types = this.typesByDirname;

        for (var bit = 0; bit < tokens.length; ++bit) {
            const token = tokens[bit];
            const prefix = bit > 0 ? [tokens[bit - 1]] : [];
            if (token === 'templates') {
                this.templates.push({
                    name: prefix.concat(tokens.slice(bit + 1)).join('/'),
                    code: this.compileTemplate(filePath)
                });
                break;
            }
            if (token === 'initializers') {
                this.initializers.push(filePath);
                break;
            }
            if (types.hasOwnProperty(token)) {
                this.registrations.push({
                    type: types[token].name,
                    name: this.makeRegistrationName(prefix.concat(tokens.slice(bit + 1))),
                    fileName: filePath
                });
                break;
            }
        }

        if (bit === tokens.length) {
            switch (tokens[bit - 1]) {
            case 'component':
                this.registrations.push({
                    type: 'component',
                    name: tokens[bit - 2],
                    fileName: filePath
                });
                break;
            case 'template':
                this.templates.push({
                    name: 'components/' + tokens[bit - 2],
                    code: this.compileTemplate(filePath)
                });
                break;
            }
        }
    }

    output(stream) {
        var imports = this.registrations.map((registration, idx) => {
            var fileName = path.resolve(registration.fileName);
            if (stream.path) { fileName = path.relative(path.dirname(stream.path), fileName); }
            return `import r${idx} from '${fileName}';`;
        }).concat(this.initializers.map(fileName => {
            fileName = path.resolve(fileName);
            if (stream.path) { fileName = path.relative(path.dirname(stream.path), fileName); }
            return `import {} from '${fileName}';`;
        })).join("\n");

        var options = [];
        Object.keys(this.typesByName).forEach(key => {
            const items = this.typesByName[key].options;
            if (Object.keys(items).length > 0) {
                const opts = Object.keys(items).map(optKey => {
                    const optValue = items[optKey];
                    return `${optKey}: ${optValue}`;
                }).join(', ');
                options.push(`    app.registerOptionsForType('${key}', {${opts}});`);
            }
        });

        var registrations = this.registrations.map((registration, idx) => {
            return `    app.register("${registration.type}:${registration.name}", r${idx});`
        }).join("\n");

        var templates = this.templates.map(template => {
            return `    t["${template.name}"] = Ember.HTMLBars.template(${template.code});`;
        }).join("\n");

        stream.write(
`import Ember from 'ember';
${imports}

Ember.Application.initializer({
  name: 'registrations',
  initialize: function (app) {
    var t = Ember.TEMPLATES;
${options}
${registrations}
${templates}
  }
});
`
        , 'utf-8');
    }
}

/****************************************************************************/

(function main() {
    const args = parseArgs(process.argv);
    const config = parseConfig(args.input);

    var generator = new Generator(config);

    var rootPromises = config.roots.map(function (path) {
        path = findPath(path, args.includes);
        return walkPath(path, function (fileName) {
            generator.handleFile(fileName, path);
        });
    });

    var importPromises = config.imports.map(function (path) {
        path = findPath(path, args.includes);
        return walkPath(path, function (fileName) {
            generator.handleFile(fileName, null);
        });
    });

    Promise.all(rootPromises.concat(importPromises)).then(function () {
        generator.output(args.output === '-'
                         ? process.stdout
                         : fs.WriteStream(args.output));
    }, error => {
        console.error("Path enumeration failed: " + error.toString());
        throw error;
    });
})();

sample-config.ini

; Uses INI syntax
; paths are relative to this file

roots[] = myproject
roots[] = path/to/mylibrary
register = adapter, controller, helper, model, route, service, view
 
[registrations]
model = singleton:false