From 3f0ca274229606c69366a2db03abc35b8af11dbc Mon Sep 17 00:00:00 2001
From: Izaak Schroeder <izaak.schroeder@gmail.com>
Date: Wed, 15 Apr 2015 01:56:11 -0700
Subject: [PATCH] Add missing `isNull` check for mapping vinyl metadata.

When requesting only metadata (i.e. `{ read: false }`) the check for the `.length` property on the file's contents will fail because the file has no contents. A check is added to deal with this case and a corresponding test has been provided.

Additionally the README has been updated to include an otherwise missing module, and the examples folder now includes an example for just retrieving the metadata.

This fixes https://github.com/izaakschroeder/vinyl-s3/issues/9.
---
 README.md                      |  6 +++---
 example/meta.js                | 18 ++++++++++++++++++
 lib/vinyl-stream.js            |  2 +-
 test/spec/vinyl-stream.spec.js |  6 ++++++
 4 files changed, 28 insertions(+), 4 deletions(-)
 create mode 100755 example/meta.js

diff --git a/README.md b/README.md
index bb5f769..86d1612 100644
--- a/README.md
+++ b/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`.
diff --git a/example/meta.js b/example/meta.js
new file mode 100755
index 0000000..9d64c8f
--- /dev/null
+++ b/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.');
+	});
diff --git a/lib/vinyl-stream.js b/lib/vinyl-stream.js
index b89b495..73e8671 100644
--- a/lib/vinyl-stream.js
+++ b/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;
 		}
 
diff --git a/test/spec/vinyl-stream.spec.js b/test/spec/vinyl-stream.spec.js
index 402a569..74f0ae0 100644
--- a/test/spec/vinyl-stream.spec.js
+++ b/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;
+	});
 });