Normalize fs access

1 files changed, 66 insertions, 0 deletions

diff --git a/lib/utils/fs.js b/lib/utils/fs.js
new file mode 100644
index 0000000..2fa6ff9
--- /dev/null
+++ b/lib/utils/fs.js
@@ -0,0 +1,66 @@
+var fs = require('graceful-fs');
+var mkdirp = require('mkdirp');
+var destroy = require('destroy');
+
+var Promise = require('./promise');
+
+// Write a stream to a file
+function writeStream(filename, st) {
+    var d = Promise.defer();
+
+    var wstream = fs.createWriteStream(filename);
+    var cleanup = function() {
+        destroy(wstream);
+        wstream.removeAllListeners();
+    };
+
+    wstream.on('finish', function () {
+        cleanup();
+        d.resolve();
+    });
+    wstream.on('error', function (err) {
+        cleanup();
+        d.reject(err);
+    });
+
+    st.on('error', function(err) {
+        cleanup();
+        d.reject(err);
+    });
+
+    st.pipe(wstream);
+
+    return d.promise;
+}
+
+// Copy a file using stream
+function copyFile(from, to) {
+    return Promise()
+    .then(function() {
+        return writeStream(to, fs.createReadStream(from));
+    });
+}
+
+// Return a promise resolved with a boolean
+function fileExists(filename) {
+    var d = Promise.defer();
+
+    fs.exists(filename, function(exists) {
+        d.resolve(exists);
+    });
+
+    return d.promise;
+}
+
+
+module.exports = {
+    exists: fileExists,
+    mkdirp: Promise.nfbind(mkdirp),
+    readFile: Promise.nfbind(fs.readFile),
+    writeFile: Promise.nfbind(fs.writeFile),
+    stat: Promise.nfbind(fs.stat),
+    statSync: fs.statSync,
+    readdir: Promise.nfbind(fs.readdir),
+    writeStream: writeStream,
+    copy: copyFile
+};