fix: Don't follow circular symlinks

index.js

@@ -24,6 +24,21 @@ function isFound(glob) {
  return isGlob(glob);
 }
 
+function getSymlinkInfo(filepath, cb) {
+ fs.realpath(filepath, function (err, realPath) {
+ if (err) return cb(err);
+
+ fs.lstat(realPath, function (err, lstat) {
+ if (err) return cb(err);
+
+ cb(null, {
+ destinationPath: realPath,
+ destinationStat: lstat,
+ });
+ });
+ });
+}
+
 function walkdir() {
  var readdirOpts = {
  withFileTypes: true,
@@ -95,12 +110,15 @@ function walkdir() {
 
  if (dirent.isSymbolicLink()) {
  // If it's a symlink, check if the symlink points to a directory
- fs.stat(nextpath, function (err, stats) {
+ getSymlinkInfo(nextpath, function (err, info) {
  if (err) {
  return cb(err);
  }
 
- if (stats.isDirectory()) {
+ if (
+ info.destinationStat.isDirectory() &&
+ !nextpath.startsWith(info.destinationPath + path.sep) // don't follow circular symlinks
+ ) {
  cb(null, nextpath);
  } else {
  cb();

test/fixtures/symlinks/circular-symlink

@@ -0,0 +1 @@
+../../

test/fixtures/symlinks/folder-a/folder-a-file.txt

@@ -0,0 +1 @@
+hello a

test/fixtures/symlinks/folder-a/link-to-b

@@ -0,0 +1 @@
+../folder-b

test/fixtures/symlinks/folder-b/folder-b-file.txt

@@ -0,0 +1 @@
+world b

test/fixtures/symlinks/folder-b/link-to-a

@@ -0,0 +1 @@
+../folder-a

test/index.js

@@ -765,12 +765,48 @@ function suite(moduleName) {
  dir +
  '/fixtures/symlinks/symlink-dest/hey/isaidhey/whatsgoingon/test.txt',
  },
+
+ {
+ cwd: dir,
+ base: dir + '/fixtures/symlinks',
+ path: dir + '/fixtures/symlinks/folder-a/folder-a-file.txt',
+ },
+ {
+ cwd: dir,
+ base: dir + '/fixtures/symlinks',
+ path: dir + '/fixtures/symlinks/folder-b/folder-b-file.txt',
+ },
+
+ // It should follow these circular symlinks, but not infinitely
+ {
+ cwd: dir,
+ base: dir + '/fixtures/symlinks',
+ path: dir + '/fixtures/symlinks/folder-a/link-to-b/folder-b-file.txt',
+ },
+ {
+ cwd: dir,
+ base: dir + '/fixtures/symlinks',
+ path: dir + '/fixtures/symlinks/folder-b/link-to-a/folder-a-file.txt',
+ },
+
+ // And it should follow a symlink to a parent directory (circular symlink) without blowing up
+ {
+ cwd: dir,
+ base: dir + '/fixtures/symlinks',
+ path:
+ dir +
+ '/fixtures/symlinks/symlink-dest/hey/isaidhey/whatsgoingon/test.txt',
+ },
  ];
 
  function assert(pathObjs) {
- expect(pathObjs.length).toBe(2);
+ expect(pathObjs.length).toBe(6);
  expect(pathObjs).toContainEqual(expected[0]);
  expect(pathObjs).toContainEqual(expected[1]);
+ expect(pathObjs).toContainEqual(expected[2]);
+ expect(pathObjs).toContainEqual(expected[3]);
+ expect(pathObjs).toContainEqual(expected[4]);
+ expect(pathObjs).toContainEqual(expected[5]);
  }
 
  stream.pipeline(