Allow uploading media files from file streams

lib/file_uploader.js

@@ -2,6 +2,8 @@ var assert = require('assert');
 var fs = require('fs');
 var mime = require('mime');
 var util = require('util');
+var request = require('http');
+var fileType = require('file-type');
 
 var MAX_FILE_SIZE_BYTES = 15 * 1024 * 1024;
 var MAX_FILE_CHUNK_BYTES = 5 * 1024 * 1024;
@@ -14,17 +16,28 @@ var MAX_FILE_CHUNK_BYTES = 5 * 1024 * 1024;
  *     console.log(err, bodyObj);
  *   })
  *
- * @param  {Object}         params  Object of the form { file_path: String }.
+ *   var request = require('request')
+ *   var stream = request('http://www.domain.com/file_to_upload.ext')
+ *   var fu = new FileUploader({ file_stream: stream }, twit);
+ *   fu.upload(function (err, bodyObj, resp) {
+ *     console.log(err, bodyObj);
+ *   })
+ *
+ * @param  {Object}         params  Object of the form { file_path: String } or { file_strea: ReadableStream }
  * @param  {Twit(object)}   twit    Twit instance.
  */
 var FileUploader = function (params, twit) {
   assert(params)
-  assert(params.file_path, 'Must specify `file_path` to upload a file. Got: ' + params.file_path + '.')
+  assert(params.file_path || params.file_stream, 'Must specify `file_path` or `file_stream` to upload a file.')
   var self = this;
   self._file_path = params.file_path;
+  self._file_stream = params.file_stream;
+  self._remoteUpload = self._file_stream ? true : false;
   self._twit = twit;
   self._isUploading = false;
   self._isFileStreamEnded = false;
+
+  if (self._remoteUpload) {self._file_stream.pause();}
 }
 
 /**
@@ -43,7 +56,7 @@ FileUploader.prototype.upload = function (cb) {
     } else {
       var mediaTmpId = bodyObj.media_id_string;
       var chunkNumber = 0;
-      var mediaFile = fs.createReadStream(self._file_path, { highWatermark: MAX_FILE_CHUNK_BYTES });
+      var mediaFile = self._file_stream || fs.createReadStream(self._file_path, { highWatermark: MAX_FILE_CHUNK_BYTES });
 
       mediaFile.on('data', function (chunk) {
         // Pause our file stream from emitting `data` events until the upload of this chunk completes.
@@ -75,6 +88,7 @@ FileUploader.prototype.upload = function (cb) {
           self._finalizeMedia(mediaTmpId, cb);
         }
       });
+      mediaFile.resume();
     }
   })
 }
@@ -116,28 +130,61 @@ FileUploader.prototype._appendMedia = function(media_id_string, chunk_part, segm
   }, cb);
 }
 
+FileUploader.prototype._getFileInfoForUpload = function(cb) {
+  var self = this;
+
+  if (self._remoteUpload === true) {
+
+    request.get(self._file_stream.uri.href, function(res){
+      res.once('data', function(chunk){
+
+        var len = res.headers['content-length']
+        if (!len) {
+          return cb(new Error('Unable to determine file size'))
+        }
+        len = +len
+        if (len !== len) {
+          return cb(new Error('Invalid Content-Length received'))
+        }
+
+        var mediaFileSizeBytes = +res.headers['content-length']
+        var mediaType = fileType(chunk)["mime"];
+
+        cb(null, mediaType, mediaFileSizeBytes);
+        res.destroy();
+      });
+    });
+  }
+  else {
+    var mediaType = mime.lookup(self._file_path);
+    var mediaFileSizeBytes = fs.statSync(self._file_path).size;
+    cb(null, mediaType, mediaFileSizeBytes);
+  }
+}
+
 /**
  * Send INIT command for our underlying media object.
  *
  * @param  {Function} cb
  */
 FileUploader.prototype._initMedia = function (cb) {
   var self = this;
-  var mediaType = mime.lookup(self._file_path);
-  var mediaFileSizeBytes = fs.statSync(self._file_path).size;
-
-  // Check the file size - it should not go over 15MB for video.
-  // See https://dev.twitter.com/rest/reference/post/media/upload-chunked
-  if (mediaFileSizeBytes < MAX_FILE_SIZE_BYTES) {
-    self._twit.post('media/upload', {
-      'command': 'INIT',
-      'media_type': mediaType,
-      'total_bytes': mediaFileSizeBytes
-    }, cb);
-  } else {
-    var errMsg = util.format('This file is too large. Max size is %dB. Got: %dB.', MAX_FILE_SIZE_BYTES, mediaFileSizeBytes);
-    cb(new Error(errMsg));
-  }
+
+  self._getFileInfoForUpload(function(err, mediaType, mediaFileSizeBytes){
+
+    // Check the file size - it should not go over 15MB for video.
+    // See https://dev.twitter.com/rest/reference/post/media/upload-chunked
+    if (mediaFileSizeBytes < MAX_FILE_SIZE_BYTES) {
+      self._twit.post('media/upload', {
+        'command': 'INIT',
+        'media_type': mediaType,
+        'total_bytes': mediaFileSizeBytes
+      }, cb);
+    } else {
+      var errMsg = util.format('This file is too large. Max size is %dB. Got: %dB.', MAX_FILE_SIZE_BYTES, mediaFileSizeBytes);
+      cb(new Error(errMsg));
+    }
+  });
 }
 
 module.exports = FileUploader

package.json

@@ -13,6 +13,7 @@
   ],
   "dependencies": {
     "bluebird": "^3.1.5",
+    "file-type": "^3.9.0",
     "mime": "^1.3.4",
     "request": "^2.68.0"
   },