Merge pull request #73 from alexindigo/71_read_range

#71 Respect bytes range in a read stream.

lib/form_data.js

@@ -79,14 +79,38 @@ FormData.prototype._trackLength = function(header, value, options) {
   this._lengthRetrievers.push(function(next) {
 
     if (value.hasOwnProperty('fd')) {
-      fs.stat(value.path, function(err, stat) {
-        if (err) {
-          next(err);
-          return;
-        }
 
-        next(null, stat.size);
-      });
+      // take read range into a account
+      // `end` = Infinity –> read file till the end
+      //
+      // TODO: Looks like there is bug in Node fs.createReadStream
+      // it doesn't respect `end` options without `start` options
+      // Fix it when node fixes it.
+      // https://github.com/joyent/node/issues/7819
+      if (value.end != undefined && value.end != Infinity && value.start != undefined) {
+
+        // when end specified
+        // no need to calculate range
+        // inclusive, starts with 0
+        next(null, value.end+1 - (value.start ? value.start : 0));
+
+      // not that fast snoopy
+      } else {
+        // still need to fetch file size from fs
+        fs.stat(value.path, function(err, stat) {
+
+          var fileSize;
+
+          if (err) {
+            next(err);
+            return;
+          }
+
+          // update final size based on the range options
+          fileSize = stat.size - (value.start ? value.start : 0);
+          next(null, fileSize);
+        });
+      }
 
     // or http response
     } else if (value.hasOwnProperty('httpVersion')) {

test/fixture/veggies.txt

@@ -0,0 +1 @@
+Veggies are healthy.

test/integration/test-form-get-length.js

@@ -66,7 +66,7 @@ var fs = require('fs');
     },
     {
       name: 'my_txt',
-      value: fs.createReadStream(common.dir.fixture + '/bacon.txt'),
+      value: fs.createReadStream(common.dir.fixture + '/veggies.txt'),
     },
   ];
 
@@ -89,5 +89,3 @@ var fs = require('fs');
   fake.expectAnytime(callback, [null, expectedLength]);
   form.getLength(callback);
 })();
-
-

test/integration/test-ranged-filestream.js

@@ -0,0 +1,97 @@
+/*
+test ranged fs.createReadStream
+re: https://github.com/felixge/node-form-data/issues/71
+*/
+
+var common       = require('../common');
+var assert       = common.assert;
+var http         = require('http');
+var fs           = require('fs');
+
+var FormData     = require(common.dir.lib + '/form_data');
+var IncomingForm = require('formidable').IncomingForm;
+
+var testSubjects = {
+  'a_file': {
+    file: 'veggies.txt',
+    start: 8,
+    end: 18
+  }, 'b_file': {
+    file: 'veggies.txt',
+    start: 6
+  }, 'c_file': {
+    file: 'veggies.txt',
+    end: 16
+  }, 'd_file': {
+    file: 'veggies.txt',
+    start: 0,
+    end: 16
+  }, 'e_file': {
+    file: 'veggies.txt',
+    start: 0,
+    end: 0
+  }
+};
+
+var server = http.createServer(function(req, res) {
+  var requestBodyLength = 0;
+
+  // calculate actual length of the request body
+  req.on('data', function(data) {
+      requestBodyLength += data.length;
+  });
+
+  var form = new IncomingForm({uploadDir: common.dir.tmp});
+
+  form.parse(req);
+
+  form
+    .on('file', function(name, file) {
+
+      // make sure total Content-Length is properly calculated
+      assert.equal(req.headers['content-length'], requestBodyLength);
+      // make sure chunks are the same size
+      assert.equal(file.size, testSubjects[name].readSize);
+    })
+    .on('end', function() {
+      res.writeHead(200);
+      res.end('done');
+    });
+});
+
+
+server.listen(common.port, function() {
+  var form = new FormData();
+  var name, options;
+
+  // add test subjects to the form
+  for (name in testSubjects) {
+    if (!testSubjects.hasOwnProperty(name)) continue;
+
+    options = {encoding: 'utf8'};
+    testSubjects[name].start && (options.start = testSubjects[name].start);
+    testSubjects[name].end && (options.end = testSubjects[name].end);
+
+    form.append(name, testSubjects[name].fsStream = fs.createReadStream(common.dir.fixture + '/' + testSubjects[name].file, options));
+
+    // calculate data size
+    testSubjects[name].readSize = 0;
+    testSubjects[name].fsStream.on('data', function(data) {
+      this.readSize += data.length;
+    }.bind(testSubjects[name]));
+  }
+
+  form.submit('http://localhost:' + common.port + '/', function(err, res) {
+    if (err) {
+      throw err;
+    }
+
+    assert.strictEqual(res.statusCode, 200);
+
+    // unstuck new streams
+    res.resume();
+
+    server.close();
+  });
+
+});