diff --git a/index.js b/index.js
index 558c449..973b7cc 100644
--- a/index.js
+++ b/index.js
@@ -84,9 +84,7 @@ function compression (options) {
         this.writeHead(this.statusCode)
       }
 
-      return stream
-        ? stream.write(toBuffer(chunk, encoding))
-        : _write.call(this, chunk, encoding)
+      return stream ? stream.write(toBuffer(chunk, encoding)) : _write.call(this, chunk, encoding)
     }
 
     res.end = function end (chunk, encoding) {
@@ -111,9 +109,7 @@ function compression (options) {
       ended = true
 
       // write Buffer for Node.js 0.8
-      return chunk
-        ? stream.end(toBuffer(chunk, encoding))
-        : stream.end()
+      return chunk ? stream.end(toBuffer(chunk, encoding)) : stream.end()
     }
 
     res.on = function on (type, listener) {
@@ -190,9 +186,7 @@ function compression (options) {
 
       // compression stream
       debug('%s compression', method)
-      stream = method === 'gzip'
-        ? zlib.createGzip(opts)
-        : zlib.createDeflate(opts)
+      stream = method === 'gzip' ? zlib.createGzip(opts) : zlib.createDeflate(opts)
 
       // add buffered listeners to stream
       addListeners(stream, stream.on, listeners)
@@ -241,9 +235,7 @@ function chunkLength (chunk, encoding) {
     return 0
   }
 
-  return !Buffer.isBuffer(chunk)
-    ? Buffer.byteLength(chunk, encoding)
-    : chunk.length
+  return !Buffer.isBuffer(chunk) ? Buffer.byteLength(chunk, encoding) : chunk.length
 }
 
 /**
@@ -272,8 +264,7 @@ function shouldTransform (req, res) {
 
   // Don't compress for Cache-Control: no-transform
   // https://tools.ietf.org/html/rfc7234#section-5.2.2.4
-  return !cacheControl ||
-    !cacheControlNoTransformRegExp.test(cacheControl)
+  return !cacheControl || !cacheControlNoTransformRegExp.test(cacheControl)
 }
 
 /**
@@ -282,7 +273,5 @@ function shouldTransform (req, res) {
  */
 
 function toBuffer (chunk, encoding) {
-  return !Buffer.isBuffer(chunk)
-    ? Buffer.from(chunk, encoding)
-    : chunk
+  return !Buffer.isBuffer(chunk) ? Buffer.from(chunk, encoding) : chunk
 }
diff --git a/test/compression.js b/test/compression.js
index 554477e..6dae3b7 100644
--- a/test/compression.js
+++ b/test/compression.js
@@ -26,11 +26,7 @@ describe('compression()', function () {
       res.end('hello, world')
     })
 
-    request(server)
-      .head('/')
-      .set('Accept-Encoding', 'gzip')
-      .expect(shouldNotHaveHeader('Content-Encoding'))
-      .expect(200, done)
+    request(server).head('/').set('Accept-Encoding', 'gzip').expect(shouldNotHaveHeader('Content-Encoding')).expect(200, done)
   })
 
   it('should skip unknown accept-encoding', function (done) {
@@ -39,11 +35,7 @@ describe('compression()', function () {
       res.end('hello, world')
     })
 
-    request(server)
-      .get('/')
-      .set('Accept-Encoding', 'bogus')
-      .expect(shouldNotHaveHeader('Content-Encoding'))
-      .expect(200, done)
+    request(server).get('/').set('Accept-Encoding', 'bogus').expect(shouldNotHaveHeader('Content-Encoding')).expect(200, done)
   })
 
   it('should skip if content-encoding already set', function (done) {
@@ -53,11 +45,7 @@ describe('compression()', function () {
       res.end('hello, world')
     })
 
-    request(server)
-      .get('/')
-      .set('Accept-Encoding', 'gzip')
-      .expect('Content-Encoding', 'x-custom')
-      .expect(200, 'hello, world', done)
+    request(server).get('/').set('Accept-Encoding', 'gzip').expect('Content-Encoding', 'x-custom').expect(200, 'hello, world', done)
   })
 
   it('should set Vary', function (done) {
@@ -66,11 +54,7 @@ describe('compression()', function () {
       res.end('hello, world')
     })
 
-    request(server)
-      .get('/')
-      .set('Accept-Encoding', 'gzip')
-      .expect('Content-Encoding', 'gzip')
-      .expect('Vary', 'Accept-Encoding', done)
+    request(server).get('/').set('Accept-Encoding', 'gzip').expect('Content-Encoding', 'gzip').expect('Vary', 'Accept-Encoding', done)
   })
 
   it('should set Vary even if Accept-Encoding is not set', function (done) {
@@ -79,11 +63,7 @@ describe('compression()', function () {
       res.end('hello, world')
     })
 
-    request(server)
-      .get('/')
-      .expect('Vary', 'Accept-Encoding')
-      .expect(shouldNotHaveHeader('Content-Encoding'))
-      .expect(200, done)
+    request(server).get('/').expect('Vary', 'Accept-Encoding').expect(shouldNotHaveHeader('Content-Encoding')).expect(200, done)
   })
 
   it('should not set Vary if Content-Type does not pass filter', function (done) {
@@ -92,10 +72,7 @@ describe('compression()', function () {
       res.end()
     })
 
-    request(server)
-      .get('/')
-      .expect(shouldNotHaveHeader('Vary'))
-      .expect(200, done)
+    request(server).get('/').expect(shouldNotHaveHeader('Vary')).expect(200, done)
   })
 
   it('should set Vary for HEAD request', function (done) {
@@ -104,10 +81,7 @@ describe('compression()', function () {
       res.end('hello, world')
     })
 
-    request(server)
-      .head('/')
-      .set('Accept-Encoding', 'gzip')
-      .expect('Vary', 'Accept-Encoding', done)
+    request(server).head('/').set('Accept-Encoding', 'gzip').expect('Vary', 'Accept-Encoding', done)
   })
 
   it('should transfer chunked', function (done) {
@@ -116,10 +90,7 @@ describe('compression()', function () {
       res.end('hello, world')
     })
 
-    request(server)
-      .get('/')
-      .set('Accept-Encoding', 'gzip')
-      .expect('Transfer-Encoding', 'chunked', done)
+    request(server).get('/').set('Accept-Encoding', 'gzip').expect('Transfer-Encoding', 'chunked', done)
   })
 
   it('should remove Content-Length for chunked', function (done) {
@@ -128,11 +99,7 @@ describe('compression()', function () {
       res.end('hello, world')
     })
 
-    request(server)
-      .get('/')
-      .expect('Content-Encoding', 'gzip')
-      .expect(shouldNotHaveHeader('Content-Length'))
-      .expect(200, done)
+    request(server).get('/').expect('Content-Encoding', 'gzip').expect(shouldNotHaveHeader('Content-Length')).expect(200, done)
   })
 
   it('should work with encoding arguments', function (done) {
@@ -142,11 +109,7 @@ describe('compression()', function () {
       res.end('world', 'utf8')
     })
 
-    request(server)
-      .get('/')
-      .set('Accept-Encoding', 'gzip')
-      .expect('Transfer-Encoding', 'chunked')
-      .expect(200, 'hello, world', done)
+    request(server).get('/').set('Accept-Encoding', 'gzip').expect('Transfer-Encoding', 'chunked').expect(200, 'hello, world', done)
   })
 
   it('should allow writing after close', function (done) {
@@ -229,17 +192,24 @@ describe('compression()', function () {
     var client
     var drained = false
     var resp
-    var server = createServer({ filter: function () { return false } }, function (req, res) {
-      resp = res
-
-      res.on('drain', function () {
-        drained = true
-      })
+    var server = createServer(
+      {
+        filter: function () {
+          return false
+        }
+      },
+      function (req, res) {
+        resp = res
+
+        res.on('drain', function () {
+          drained = true
+        })
 
-      res.setHeader('Content-Type', 'text/plain')
-      res.write('start')
-      pressure()
-    })
+        res.setHeader('Content-Type', 'text/plain')
+        res.write('start')
+        pressure()
+      }
+    )
 
     crypto.randomBytes(1024 * 128, function (err, chunk) {
       if (err) return done(err)
@@ -329,12 +299,13 @@ describe('compression()', function () {
         request.on('response', function (headers) {
           assert.strictEqual(headers['content-encoding'], 'gzip')
         })
-        var chunks = [];
+        var chunks = []
         request.on('data', function (chunk) {
-          chunks.push(chunk);
+          chunks.push(chunk)
         })
         request.on('end', function () {
-          zlib.gunzip(Buffer.concat(chunks), function(err, data) { 
+          zlib.gunzip(Buffer.concat(chunks), function (err, data) {
+            if (err) return done(err)
             assert.strictEqual(data.toString(), 'hello, world')
             closeHttp2(client, server, done)
           })
@@ -352,11 +323,7 @@ describe('compression()', function () {
         res.end('hello, world')
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect(shouldNotHaveHeader('Content-Encoding'))
-        .expect(200, done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect(shouldNotHaveHeader('Content-Encoding')).expect(200, done)
     })
 
     it('should compress responses above the threshold size', function (done) {
@@ -366,10 +333,7 @@ describe('compression()', function () {
         res.end(Buffer.alloc(2048))
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect('Content-Encoding', 'gzip', done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect('Content-Encoding', 'gzip', done)
     })
 
     it('should compress when streaming without a content-length', function (done) {
@@ -381,10 +345,7 @@ describe('compression()', function () {
         }, 10)
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect('Content-Encoding', 'gzip', done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect('Content-Encoding', 'gzip', done)
     })
 
     it('should not compress when streaming and content-length is lower than threshold', function (done) {
@@ -397,11 +358,7 @@ describe('compression()', function () {
         }, 10)
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect(shouldNotHaveHeader('Content-Encoding'))
-        .expect(200, done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect(shouldNotHaveHeader('Content-Encoding')).expect(200, done)
     })
 
     it('should compress when streaming and content-length is larger than threshold', function (done) {
@@ -414,10 +371,7 @@ describe('compression()', function () {
         }, 10)
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect('Content-Encoding', 'gzip', done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect('Content-Encoding', 'gzip', done)
     })
 
     // res.end(str, encoding) broken in node.js 0.8
@@ -428,11 +382,7 @@ describe('compression()', function () {
         res.end('2e2e2e2e', 'hex')
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect(shouldNotHaveHeader('Content-Encoding'))
-        .expect(200, '....', done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect(shouldNotHaveHeader('Content-Encoding')).expect(200, '....', done)
     })
 
     it('should consider res.end() as 0 length', function (done) {
@@ -441,11 +391,7 @@ describe('compression()', function () {
         res.end()
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect(shouldNotHaveHeader('Content-Encoding'))
-        .expect(200, '', done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect(shouldNotHaveHeader('Content-Encoding')).expect(200, '', done)
     })
 
     it('should work with res.end(null)', function (done) {
@@ -454,11 +400,7 @@ describe('compression()', function () {
         res.end(null)
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect(shouldNotHaveHeader('Content-Encoding'))
-        .expect(200, '', done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect(shouldNotHaveHeader('Content-Encoding')).expect(200, '', done)
     })
   })
 
@@ -469,10 +411,7 @@ describe('compression()', function () {
         res.end('hello, world')
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect('Content-Encoding', 'gzip', done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect('Content-Encoding', 'gzip', done)
     })
 
     it('should return false writing after end', function (done) {
@@ -483,10 +422,7 @@ describe('compression()', function () {
         assert.ok(res.end() === false)
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect('Content-Encoding', 'gzip', done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect('Content-Encoding', 'gzip', done)
     })
   })
 
@@ -497,10 +433,7 @@ describe('compression()', function () {
         res.end('hello, world')
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'deflate')
-        .expect('Content-Encoding', 'deflate', done)
+      request(server).get('/').set('Accept-Encoding', 'deflate').expect('Content-Encoding', 'deflate', done)
     })
   })
 
@@ -511,10 +444,7 @@ describe('compression()', function () {
         res.end('hello, world')
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip, deflate')
-        .expect('Content-Encoding', 'gzip', done)
+      request(server).get('/').set('Accept-Encoding', 'gzip, deflate').expect('Content-Encoding', 'gzip', done)
     })
   })
 
@@ -525,10 +455,7 @@ describe('compression()', function () {
         res.end('hello, world')
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'deflate, gzip')
-        .expect('Content-Encoding', 'gzip', done)
+      request(server).get('/').set('Accept-Encoding', 'deflate, gzip').expect('Content-Encoding', 'gzip', done)
     })
   })
 
@@ -555,12 +482,7 @@ describe('compression()', function () {
         res.end('hello, world')
       })
 
-      request(server)
-        .get('/')
-        .set('Accept-Encoding', 'gzip')
-        .expect('Cache-Control', 'no-transform')
-        .expect(shouldNotHaveHeader('Vary'))
-        .expect(200, done)
+      request(server).get('/').set('Accept-Encoding', 'gzip').expect('Cache-Control', 'no-transform').expect(shouldNotHaveHeader('Vary')).expect(200, done)
     })
   })
 
@@ -574,9 +496,7 @@ describe('compression()', function () {
         res.end(String(compression.filter(req, res)))
       })
 
-      request(server)
-        .get('/')
-        .expect(200, 'false', done)
+      request(server).get('/').expect(200, 'false', done)
     })
 
     it('should return true for "text/plain"', function (done) {
@@ -585,9 +505,7 @@ describe('compression()', function () {
         res.end(String(compression.filter(req, res)))
       })
 
-      request(server)
-        .get('/')
-        .expect(200, 'true', done)
+      request(server).get('/').expect(200, 'true', done)
     })
 
     it('should return false for "application/x-bogus"', function (done) {
@@ -596,25 +514,19 @@ describe('compression()', function () {
         res.end(String(compression.filter(req, res)))
       })
 
-      request(server)
-        .get('/')
-        .expect(200, 'false', done)
+      request(server).get('/').expect(200, 'false', done)
     })
   })
 
   describe('res.flush()', function () {
     it('should always be present', function (done) {
       var server = createServer(null, function (req, res) {
-        res.statusCode = typeof res.flush === 'function'
-          ? 200
-          : 500
+        res.statusCode = typeof res.flush === 'function' ? 200 : 500
         res.flush()
         res.end()
       })
 
-      request(server)
-        .get('/')
-        .expect(200, done)
+      request(server).get('/').expect(200, done)
     })
 
     it('should flush the response', function (done) {
@@ -637,10 +549,13 @@ describe('compression()', function () {
         .get('/')
         .set('Accept-Encoding', 'gzip')
         .request()
-        .on('response', unchunk('gzip', onchunk, function (err) {
-          if (err) return done(err)
-          server.close(done)
-        }))
+        .on(
+          'response',
+          unchunk('gzip', onchunk, function (err) {
+            if (err) return done(err)
+            server.close(done)
+          })
+        )
         .end()
     })
 
@@ -663,10 +578,13 @@ describe('compression()', function () {
         .get('/')
         .set('Accept-Encoding', 'gzip')
         .request()
-        .on('response', unchunk('gzip', onchunk, function (err) {
-          if (err) return done(err)
-          server.close(done)
-        }))
+        .on(
+          'response',
+          unchunk('gzip', onchunk, function (err) {
+            if (err) return done(err)
+            server.close(done)
+          })
+        )
         .end()
     })
 
@@ -689,10 +607,13 @@ describe('compression()', function () {
         .get('/')
         .set('Accept-Encoding', 'deflate')
         .request()
-        .on('response', unchunk('deflate', onchunk, function (err) {
-          if (err) return done(err)
-          server.close(done)
-        }))
+        .on(
+          'response',
+          unchunk('deflate', onchunk, function (err) {
+            if (err) return done(err)
+            server.close(done)
+          })
+        )
         .end()
     })
   })
@@ -737,20 +658,20 @@ function createHttp2Client (port) {
 function closeHttp2 (client, server, callback) {
   if (typeof client.shutdown === 'function') {
     // this is the node v8.x way of closing the connections
-      client.shutdown({}, function () {
-        server.close(function () {
-          callback()
-        })
+    client.shutdown({}, function () {
+      server.close(function () {
+        callback()
       })
+    })
   } else {
     // this is the node v9.x onwards way of closing the connections
-      client.close(function () {
-        // force existing connections to time out after 1ms.
-        // this is done to force the server to close in some cases where it wouldn't do it otherwise.
-        server.close(function () {
-          callback()
-        })
+    client.close(function () {
+      // force existing connections to time out after 1ms.
+      // this is done to force the server to close in some cases where it wouldn't do it otherwise.
+      server.close(function () {
+        callback()
       })
+    })
   }
 }