hush: wait for close event instead of finish event

use stream.pipeline to cover all the corner cases

src/hush.js

@@ -6,6 +6,7 @@ const assert = require('assert'),
     debug = require('debug')('box:hush'),
     fs = require('fs'),
     ProgressStream = require('./progress-stream.js'),
+    stream = require('stream'),
     TransformStream = require('stream').Transform;
 
 class EncryptStream extends TransformStream {
@@ -184,32 +185,28 @@ function createWriteStream(destFile, encryption) {
     assert.strictEqual(typeof destFile, 'string');
     assert.strictEqual(typeof encryption, 'object');
 
-    const stream = fs.createWriteStream(destFile);
+    const destStream = fs.createWriteStream(destFile);
     const ps = new ProgressStream({ interval: 10000 }); // display a progress every 10 seconds
 
-    stream.on('error', function (error) {
-        debug(`createWriteStream: write stream error ${destFile}. %o`, error);
-        ps.emit('error', new BoxError(BoxError.FS_ERROR, `Write error ${destFile}: ${error.message}`));
-    });
-
-    stream.on('finish', function () {
-        debug('createWriteStream: done.');
-        // we use a separate event because ps is a through2 stream which emits 'finish' event indicating end of inStream and not write
-        ps.emit('done');
-    });
+    const streams = [ ps ];
 
     if (encryption) {
-        let decrypt = new DecryptStream(encryption);
-        decrypt.on('error', function (error) {
-            debug(`createWriteStream: decrypt stream error ${destFile}. %o`, error);
-            ps.emit('error', new BoxError(BoxError.CRYPTO_ERROR, `Decryption error at ${destFile}: ${error.message}`));
-        });
-
-        ps.pipe(decrypt).pipe(stream);
-    } else {
-        ps.pipe(stream);
+        const decryptStream = new DecryptStream(encryption);
+        streams.push(decryptStream);
     }
 
+    streams.push(destStream);
+
+    stream.pipeline(streams, function (error) {
+        if (error) {
+            debug(`createWriteStream: write stream error ${destFile}. %o`, error);
+            ps.emit('error', new BoxError(BoxError.FS_ERROR, `Write error ${destFile}: ${error.message}`));
+        } else {
+            debug(`createWriteStream: ${destFile} done`);
+            return ps.emit('done');
+        }
+    });
+
     return ps;
 }