Merge pull request #173 from fastify/fix_172

Author: jsumners

index.js

@@ -403,7 +403,7 @@ function setVaryHeader (reply) {
   if (reply.hasHeader('Vary')) {
     const varyHeader = Array.isArray(reply.getHeader('Vary')) ? reply.getHeader('Vary') : [reply.getHeader('Vary')]
     if (!varyHeader.some((h) => h.includes('accept-encoding'))) {
-      reply.header('Vary', [...varyHeader, 'accept-encoding'])
+      reply.header('Vary', `${varyHeader.join(', ')}, accept-encoding`)
     }
   } else {
     reply.header('Vary', 'accept-encoding')

test/test-global-compress.js

@@ -1829,7 +1829,7 @@ test('should concat accept-encoding to vary header if present', t => {
     }
   }, (err, res) => {
     t.error(err)
-    t.same(res.headers.vary, ['different-header', 'accept-encoding'])
+    t.same(res.headers.vary, 'different-header, accept-encoding')
   })
 
   fastify.inject({
@@ -1840,7 +1840,7 @@ test('should concat accept-encoding to vary header if present', t => {
     }
   }, (err, res) => {
     t.error(err)
-    t.same(res.headers.vary, ['different-header', 'my-header', 'accept-encoding'])
+    t.same(res.headers.vary, 'different-header, my-header, accept-encoding')
   })
 })
 
@@ -1856,7 +1856,7 @@ test('should not add accept-encoding to vary header if already present', t => {
   })
 
   fastify.get('/foo', (req, reply) => {
-    reply.header('vary', ['accept-encoding', 'different-header', 'my-header'])
+    reply.header('vary', 'accept-encoding, different-header, my-header')
     reply.type('text/plain').compress(createReadStream('./package.json'))
   })
 
@@ -1879,6 +1879,6 @@ test('should not add accept-encoding to vary header if already present', t => {
     }
   }, (err, res) => {
     t.error(err)
-    t.same(res.headers.vary, ['accept-encoding', 'different-header', 'my-header'])
+    t.same(res.headers.vary, 'accept-encoding, different-header, my-header')
   })
 })