Implement initial getLength

felixge · felixge · commit 9060c91b861a · 2011-05-28T20:47:14.000+02:00
Doesn't deal with file streams yet
diff --git a/lib/form_data.js b/lib/form_data.js
@@ -5,46 +5,73 @@ var mime = require('mime');
 
 module.exports = FormData;
 function FormData() {
+  this._overheadLength = 0;
+  this._valueLength = 0;
+
   CombinedStream.call(this);
 }
 util.inherits(FormData, CombinedStream);
 
+FormData.LINE_BREAK = '\r\n';
+
 FormData.prototype.append = function(field, value) {
-  var parentAppend = CombinedStream.prototype.append;
+  var append = CombinedStream.prototype.append.bind(this);
+
+  var header = this._multiPartHeader(field, value);
+  var footer = this._multiPartFooter(field, value);
 
-  parentAppend.call(this, this._multiPartHeader.bind(this, field, value));
-  parentAppend.call(this, value);
-  parentAppend.call(this, this._multiPartFooter.bind(this, field, value));
+  append(header);
+  append(value);
+  append(footer);
+
+  this._trackLength(header, value)
 };
 
-FormData.prototype._multiPartHeader = function(field, value, next) {
-  var boundary = this.getBoundary();
+FormData.prototype._trackLength = function(header, value) {
+  var valueLength = 0;
+  if (Buffer.isBuffer(value)) {
+    valueLength = value.length;
+  } else if (typeof value === 'string') {
+    valueLength = Buffer.byteLength(value);
+  }
+
+  this._valueLength += valueLength;
+  this._overheadLength +=
+    Buffer.byteLength(header) +
+    + FormData.LINE_BREAK.length;
+};
 
+FormData.prototype._multiPartHeader = function(field, value) {
+  var boundary = this.getBoundary();
   var header =
-    '--' + boundary
-    + '\r\n'
-    + 'Content-Disposition: form-data; name="' + field + '"';
+    '--' + boundary + FormData.LINE_BREAK +
+    'Content-Disposition: form-data; name="' + field + '"';
 
   if (value.path) {
     header +=
-      '; filename="' + path.basename(value.path) + '"\r\n'
-      + 'Content-Type: ' + mime.lookup(value.path);
+      '; filename="' + path.basename(value.path) + '"' + FormData.LINE_BREAK +
+      'Content-Type: ' + mime.lookup(value.path);
   }
 
-  header += '\r\n\r\n';
-
-  next(header);
+  header += FormData.LINE_BREAK + FormData.LINE_BREAK;
+  return header;
 };
 
-FormData.prototype._multiPartFooter = function(field, value, next) {
-  var footer = '\r\n';
+FormData.prototype._multiPartFooter = function(field, value) {
+  return function(next) {
+    var footer = FormData.LINE_BREAK;
 
-  var lastPart = (this._streams.length === 0);
-  if (lastPart) {
-    footer += '--' + this.getBoundary() + '--';
-  }
+    var lastPart = (this._streams.length === 0);
+    if (lastPart) {
+      footer += this._lastBoundary();
+    }
 
-  next(footer);
+    next(footer);
+  }.bind(this);
+};
+
+FormData.prototype._lastBoundary = function() {
+  return '--' + this.getBoundary() + '--';
 };
 
 FormData.prototype.getHeaders = function(userHeaders) {
@@ -77,3 +104,13 @@ FormData.prototype._generateBoundary = function() {
 
   this._boundary = boundary;
 };
+
+FormData.prototype.getLength = function(cb) {
+  var knownLength = this._overheadLength + this._valueLength;
+
+  if (this._streams.length) {
+    knownLength += this._lastBoundary().length;
+  }
+
+  process.nextTick(cb.bind(this, null, knownLength));
+};
diff --git a/test/integration/test-form-get-length.js b/test/integration/test-form-get-length.js
@@ -0,0 +1,51 @@
+var common = require('../common');
+var assert = common.assert;
+var FormData = require(common.dir.lib + '/form_data');
+var fake = require('fake').create();
+
+(function testEmptyForm() {
+  var form = new FormData();
+  var callback = fake.callback(arguments.callee.name + '-getLength');
+  var calls = fake.expect(callback, [null, 0]).calls;
+
+  form.getLength(callback);
+
+  // Make sure our response is async
+  assert.strictEqual(calls.length, 0);
+})();
+
+(function testUtf8String() {
+  var FIELD = 'my_field';
+  var VALUE = 'May the € be with you';
+
+  var form = new FormData();
+  form.append(FIELD, VALUE);
+  var callback = fake.callback(arguments.callee.name + '-getLength');
+
+  var expectedLength =
+    form._overheadLength +
+    Buffer.byteLength(VALUE) +
+    form._lastBoundary().length;
+
+  fake.expect(callback, [null, expectedLength]);
+  form.getLength(callback);
+})();
+
+(function testBuffer() {
+  var FIELD = 'my_field';
+  var VALUE = new Buffer(23);
+
+  var form = new FormData();
+  form.append(FIELD, VALUE);
+  var callback = fake.callback(arguments.callee.name + '-getLength');
+
+  var expectedLength =
+    form._overheadLength +
+    VALUE.length +
+    form._lastBoundary().length;
+
+  fake.expect(callback, [null, expectedLength]);
+  form.getLength(callback);
+})();
+
+
