Add missing isNull check for mapping vinyl metadata.

README.md

@@ -21,7 +21,6 @@ Features:
 
 ```javascript
 var gulp = require('gulp'),
-	AWS = require('aws-sdk'),
 	s3 = require('vinyl-s3');
 
 // Upload files to S3
@@ -37,13 +36,14 @@ gulp.task('download', function() {
 });
 
 // Just print a list of files
+var through2 = require('through2');
 gulp.task('meta', function() {
 	return s3.src('s3://my-bucket/foo/**/*.jpg', { read: false })
 		.pipe(through2.obj(function(file, _, callback) {
-			console.log('found:',file.path);
+			console.log(file.path);
 			callback();
 		}));
-})
+});
 ```
 
 When working with large files you may find it useful to use streaming mode instead of buffering mode. You can enable this in the `src()` family of functions by setting `{ buffer: false }`. The default mode is to use buffering as is the same with `fs.src`.

example/meta.js

@@ -0,0 +1,18 @@
+#!/usr/bin/env node
+
+'use strict';
+
+var argv = require('yargs').argv;
+
+var through2 = require('through2'),
+	s3 = require('vinyl-s3');
+
+// env AWS_PROFILE="home" ./example/meta.js "s3://my-bucket/foo/**/*.jpg"
+s3.src(argv._, { read: false })
+	.pipe(through2.obj(function onFile(file, enc, callback) {
+		console.log(file.path);
+		callback();
+	}))
+	.on('finish', function onFinish() {
+		console.log('Done.');
+	});

lib/vinyl-stream.js

@@ -37,7 +37,7 @@ module.exports = function createVinylStream(options) {
 
 		// Set the length on things like streams which are used
 		// by some frameworks.
-		if (!file.contents.length) {
+		if (!file.isNull() && !file.contents.length) {
 			file.contents.length = file.stat.size;
 		}
 

test/spec/vinyl-stream.spec.js

@@ -53,4 +53,10 @@ describe('#createVinylStream', function() {
 		stream.write({ ContentType: 'foo/bar', Key: 'key', Body: body, ContentLength: '20' });
 		expect(stream.read().contents).to.have.property('length', 20);
 	});
+
+	it('should work with null vinyl objects', function() {
+		var stream = createVinylStream({ meta: true });
+		stream.write({ ContentType: 'foo/bar', Key: 'key' });
+		expect(stream.read()).to.not.be.null;
+	});
 });