source: trip-planner-front/node_modules/globby/gitignore.js@ eed0bf8

'use strict';
const {promisify} = require('util');
const fs = require('fs');
const path = require('path');
const fastGlob = require('fast-glob');
const gitIgnore = require('ignore');
const slash = require('slash');

const DEFAULT_IGNORE = [
        '**/node_modules/**',
        '**/flow-typed/**',
        '**/coverage/**',
        '**/.git'
];

const readFileP = promisify(fs.readFile);

const mapGitIgnorePatternTo = base => ignore => {
        if (ignore.startsWith('!')) {
                return '!' + path.posix.join(base, ignore.slice(1));
        }

        return path.posix.join(base, ignore);
};

const parseGitIgnore = (content, options) => {
        const base = slash(path.relative(options.cwd, path.dirname(options.fileName)));

        return content
                .split(/\r?\n/)
                .filter(Boolean)
                .filter(line => !line.startsWith('#'))
                .map(mapGitIgnorePatternTo(base));
};

const reduceIgnore = files => {
        const ignores = gitIgnore();
        for (const file of files) {
                ignores.add(parseGitIgnore(file.content, {
                        cwd: file.cwd,
                        fileName: file.filePath
                }));
        }

        return ignores;
};

const ensureAbsolutePathForCwd = (cwd, p) => {
        cwd = slash(cwd);
        if (path.isAbsolute(p)) {
                if (slash(p).startsWith(cwd)) {
                        return p;
                }

                throw new Error(`Path ${p} is not in cwd ${cwd}`);
        }

        return path.join(cwd, p);
};

const getIsIgnoredPredecate = (ignores, cwd) => {
        return p => ignores.ignores(slash(path.relative(cwd, ensureAbsolutePathForCwd(cwd, p.path || p))));
};

const getFile = async (file, cwd) => {
        const filePath = path.join(cwd, file);
        const content = await readFileP(filePath, 'utf8');

        return {
                cwd,
                filePath,
                content
        };
};

const getFileSync = (file, cwd) => {
        const filePath = path.join(cwd, file);
        const content = fs.readFileSync(filePath, 'utf8');

        return {
                cwd,
                filePath,
                content
        };
};

const normalizeOptions = ({
        ignore = [],
        cwd = slash(process.cwd())
} = {}) => {
        return {ignore, cwd};
};

module.exports = async options => {
        options = normalizeOptions(options);

        const paths = await fastGlob('**/.gitignore', {
                ignore: DEFAULT_IGNORE.concat(options.ignore),
                cwd: options.cwd
        });

        const files = await Promise.all(paths.map(file => getFile(file, options.cwd)));
        const ignores = reduceIgnore(files);

        return getIsIgnoredPredecate(ignores, options.cwd);
};

module.exports.sync = options => {
        options = normalizeOptions(options);

        const paths = fastGlob.sync('**/.gitignore', {
                ignore: DEFAULT_IGNORE.concat(options.ignore),
                cwd: options.cwd
        });

        const files = paths.map(file => getFileSync(file, options.cwd));
        const ignores = reduceIgnore(files);

        return getIsIgnoredPredecate(ignores, options.cwd);
};