dbmedialab/reader-critics

//
// LESERKRITIKK v2 (aka Reader Critics)
// Copyright (C) 2017 DB Medialab/Aller Media AS, Oslo, Norway
// https://github.com/dbmedialab/reader-critics/
//
// 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/>.
//

import * as findRoot from 'find-root';
import * as fs from 'fs';
import * as JSON5 from 'json5';
import * as path from 'path';

import { NotFoundError } from 'app/util/errors';
import { isTest } from './environment';

/** The filesystem root of the whole project */
export const rootPath : string = findRoot((isTest && process.env.CWD !== undefined)
    ? process.env.CWD
    : path.dirname(require.main.filename));

export function loadResource(relativePath : string) : Promise <Buffer> {
    return new Promise((resolve, reject) => {
        const fullPath : string = path.join(rootPath, relativePath);

        fs.open(fullPath, 'r', (errOpen) => {
            if (errOpen) {
                if (errOpen.code === 'ENOENT') {
                    return reject(new NotFoundError(`${fullPath} does not exist`));
                }

                return reject(errOpen);
            }

            fs.readFile(fullPath, (errRead, data : Buffer) => {
                if (errRead) {
                    return reject(errRead);
                }

                return resolve(data);
            });
        });
    });
}

export function loadJSON(relativePath : string) : Promise <any> {
    return loadResource(relativePath)
        .then(buffer => JSON5.parse(buffer.toString()));
}

export function scanDir(folderName : string) : Promise <string[]> {
    return new Promise((resolve, reject) => {
        fs.readdir(folderName, (err, files : string[]) => {
            return err ? reject(err) : resolve(files);
        });
    });
}

export function watchFile(relativePath : string, callback : any) : Promise <fs.FSWatcher> {
    const fullPath : string = path.join(rootPath, relativePath);
    return new Promise((resolve) => {
        return resolve(fs.watch(fullPath, {}, callback));
    });
}