From cf7e5884cd3908f2200fac3684ebebdb5cbeb577 Mon Sep 17 00:00:00 2001
From: Samy Pesse <samypesse@gmail.com>
Date: Fri, 6 May 2016 10:53:55 +0200
Subject: [PATCH] Add method readAsStream on fs model

---
 lib/fs/node.js   |  3 ++-
 lib/models/fs.js | 29 ++++++++++++++++++++++++++++-
 lib/utils/fs.js  |  1 +
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/lib/fs/node.js b/lib/fs/node.js
index 9b8c05657..dfe9fae90 100644
--- a/lib/fs/node.js
+++ b/lib/fs/node.js
@@ -36,6 +36,7 @@ module.exports = function createNodeFS(root) {
         fsReadFile: fs.readFile,
         fsStatFile: fs.stat,
         fsReadDir: fsReadDir,
-        fsLoadObject: fsLoadObject
+        fsLoadObject: fsLoadObject,
+        fsReadAsStream: fs.readStream
     });
 };
diff --git a/lib/models/fs.js b/lib/models/fs.js
index ab65dd5bb..12aee537e 100644
--- a/lib/models/fs.js
+++ b/lib/models/fs.js
@@ -1,5 +1,6 @@
 var path = require('path');
 var Immutable = require('immutable');
+var stream = require('stream');
 
 var File = require('./file');
 var Promise = require('../utils/promise');
@@ -13,7 +14,9 @@ var FS = Immutable.Record({
     fsReadFile:       Function(),
     fsStatFile:       Function(),
     fsReadDir:        Function(),
-    fsLoadObject:     null
+
+    fsLoadObject:     null,
+    fsReadAsStream:   null
 });
 
 /**
@@ -111,6 +114,30 @@ FS.prototype.readAsString = function(filename, encoding) {
     });
 };
 
+/**
+    Read file as a stream
+
+    @param {String} filename
+    @return {Promise<Stream>}
+*/
+FS.prototype.readAsStream = function(filename) {
+    var that = this;
+    var filepath = that.resolve(filename);
+    var fsReadAsStream = this.get('fsReadAsStream');
+
+    if (fsReadAsStream) {
+        return Promise(fsReadAsStream(filepath));
+    }
+
+    return this.read(filename)
+    .then(function(buf) {
+        var bufferStream = new stream.PassThrough();
+        bufferStream.end(buf);
+
+        return bufferStream;
+    });
+};
+
 /**
     Read stat infos about a file
 
diff --git a/lib/utils/fs.js b/lib/utils/fs.js
index da22fdb33..35839a329 100644
--- a/lib/utils/fs.js
+++ b/lib/utils/fs.js
@@ -157,6 +157,7 @@ module.exports = {
     statSync: fs.statSync,
     readdir: Promise.nfbind(fs.readdir),
     writeStream: writeStream,
+    readStream: fs.createReadStream,
     copy: Promise.nfbind(cp),
     copyDir: Promise.nfbind(cpr),
     tmpFile: genTmpFile,