diff --git a/lib/storage.js b/lib/storage.js
index 4b0bfd7..fa8f12a 100755
--- a/lib/storage.js
+++ b/lib/storage.js
@@ -50,15 +50,25 @@ storage.flushToStorage = (options, callback) => {
flags = options.isDir ? 'r' : 'r+'
}
- // Windows can't fsync (FlushFileBuffers) directories. We can live with this as it cannot cause 100% dataloss
- // except in the very rare event of the first time database is loaded and a crash happens
- if (flags === 'r' && (process.platform === 'win32' || process.platform === 'win64')) return callback(null)
+ /**
+ * Some OSes and/or storage backends (augmented node fs) do not support fsync (FlushFileBuffers) directories,
+ * or calling open() on directories at all. Flushing fails silently in this case, supported by following heuristics:
+ * + isDir === true
+ * |-- open(
) -> (err.code === 'EISDIR'): can't call open() on directories (eg. BrowserFS)
+ * `-- fsync() -> (errFS.code === 'EPERM' || errFS.code === 'EISDIR'): can't fsync directory: permissions are checked
+ * on open(); EPERM error should only occur on fsync incapability and not for general lack of permissions (e.g. Windows)
+ *
+ * We can live with this as it cannot cause 100% dataloss except in the very rare event of the first time
+ * database is loaded and a crash happens.
+ */
fs.open(filename, flags, (err, fd) => {
- if (err) return callback(err)
+ if (err) {
+ return callback((err.code === 'EISDIR' && options.isDir) ? null : err)
+ }
fs.fsync(fd, errFS => {
fs.close(fd, errC => {
- if (errFS || errC) {
+ if ((errFS || errC) && !((errFS.code === 'EPERM' || errFS.code === 'EISDIR') && options.isDir)) {
const e = new Error('Failed to flush to storage')
e.errorOnFsync = errFS
e.errorOnClose = errC
diff --git a/test/byline.test.js b/test/byline.test.js
index fa07524..713d80d 100644
--- a/test/byline.test.js
+++ b/test/byline.test.js
@@ -37,7 +37,7 @@ describe('byline', function () {
lineStream.pipe(output)
output.on('close', function () {
const out = fs.readFileSync(localPath('test.txt'), 'utf8')
- const in_ = fs.readFileSync(localPath('empty.txt'), 'utf8').replace(/\n/g, '')
+ const in_ = fs.readFileSync(localPath('empty.txt'), 'utf8').replace(/\r?\n/g, '')
assert.equal(in_, out)
fs.unlinkSync(localPath('test.txt'))
done()
diff --git a/test_lac/openFdsLaunch.sh b/test_lac/openFdsLaunch.sh
index 495c8a3..7c04a5a 100755
--- a/test_lac/openFdsLaunch.sh
+++ b/test_lac/openFdsLaunch.sh
@@ -1,2 +1,3 @@
+#!/bin/sh
ulimit -n 128
node ./test_lac/openFds.test.js