feat(createReadStream): add `.fileSize` (#60)

lib/api/createReadStream.js

@@ -24,7 +24,8 @@ module.exports = function createReadStream(path, options, cb) {
     }
 
     var offset = options.start || 0;
-    var end = BigInt.fromBuffer(file.EndofFile).toNumber();
+    var fileSize = BigInt.fromBuffer(file.EndofFile).toNumber();
+    var end = fileSize;
 
     if (options.end < end) {
       end = options.end + 1; // end option is inclusive
@@ -33,6 +34,7 @@ module.exports = function createReadStream(path, options, cb) {
     var close = request.bind(undefined, 'close', file, connection);
 
     var stream = new Readable();
+    stream.fileSize = fileSize;
     if (shouldClose) {
       stream._destroy = function(err, cb) {
         close(function(err2) {

test/index.js

@@ -58,12 +58,12 @@ const tests = {
       const fd = yield client.open(file, 'r');
       $d.call(client, 'close', fd);
 
-      t.same(
-        yield getStream.buffer(
-          yield client.createReadStream('', { autoClose: false, fd })
-        ),
-        data
-      );
+      const readStream = yield client.createReadStream('', {
+        autoClose: false,
+        fd,
+      });
+      t.same(yield getStream.buffer(readStream), data);
+      t.same(readStream.fileSize, data.length);
     })
   ),
   createWriteStream: defer(