react-native/local-cli/util/findSymlinksPaths.js

60 lines
1.6 KiB
JavaScript

/**
* Copyright (c) 2015-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
const path = require('path');
const fs = require('fs');
/**
* Find and resolve symlinks in `lookupFolder`.
* Ignore any descendants of the paths in `ignoredRoots`.
*/
module.exports = function findSymlinksPaths(lookupFolder, ignoredRoots) {
const timeStart = Date.now();
const folders = fs.readdirSync(lookupFolder);
const resolvedSymlinks = [];
folders.forEach(folder => {
const visited = [];
let symlink = path.resolve(lookupFolder, folder);
while (fs.lstatSync(symlink).isSymbolicLink()) {
const index = visited.indexOf(symlink);
if (index !== -1) {
throw Error(
'Infinite symlink recursion detected:\n ' +
visited.slice(index).join('\n ')
);
}
visited.push(symlink);
symlink = path.resolve(
path.dirname(symlink),
fs.readlinkSync(symlink)
);
}
if (visited.length && !rootExists(ignoredRoots, symlink)) {
resolvedSymlinks.push(symlink);
}
});
const timeEnd = Date.now();
console.log(`Scanning ${folders.length} folders for symlinks in ${lookupFolder} (${timeEnd - timeStart}ms)`);
return resolvedSymlinks;
};
function rootExists(roots, child) {
return roots.some(root => isDescendant(root, child));
}
function isDescendant(root, child) {
return root === child || child.startsWith(root + path.sep);
}