Add support for zstd

README.md

@@ -14,8 +14,9 @@ The following compression codings are supported:
   - deflate
   - gzip
   - br (brotli)
+  - zstd (Zstandard)
 
-**Note** Brotli is supported only since Node.js versions v11.7.0 and v10.16.0.
+**Note** Brotli is supported only since Node.js versions v11.7.0 and v10.16.0. Zstd is supported only since Node.js v23.8.0 and v22.15.0.
 
 ## Install
 
@@ -46,9 +47,10 @@ as compressing will transform the body.
 #### Options
 
 `compression()` accepts these properties in the options object. In addition to
-those listed below, [zlib](https://nodejs.org/api/zlib.html) options may be
-passed in to the options object or
-[brotli](https://nodejs.org/api/zlib.html#zlib_class_brotlioptions) options.
+those listed below, [zlib](https://nodejs.org/api/zlib.html),
+[brotli](https://nodejs.org/api/zlib.html#zlib_class_brotlioptions), or
+[zstd](https://nodejs.org/api/zlib.html#class-zstdoptions) options may be
+passed in to the options object.
 
 ##### chunkSize
 
@@ -116,6 +118,11 @@ Type: `Object`
 
 This specifies the options for configuring Brotli. See [Node.js documentation](https://nodejs.org/api/zlib.html#class-brotlioptions) for a complete list of available options.
 
+##### zstd
+
+Type: `Object`
+
+This specifies the options for configuring Zstd. See [Node.js documentation](https://nodejs.org/api/zlib.html#class-zstdoptions) for a complete list of available options.
 
 ##### strategy
 

index.js

@@ -36,15 +36,33 @@ module.exports.filter = shouldCompress
  */
 var hasBrotliSupport = 'createBrotliCompress' in zlib
 
+/**
+ * @const
+ * whether current node version has zstd support
+ */
+var hasZstdSupport = 'createZstdCompress' in zlib
+
 /**
  * Module variables.
  * @private
  */
 var cacheControlNoTransformRegExp = /(?:^|,)\s*?no-transform\s*?(?:,|$)/
-var SUPPORTED_ENCODING = hasBrotliSupport ? ['br', 'gzip', 'deflate', 'identity'] : ['gzip', 'deflate', 'identity']
-var PREFERRED_ENCODING = hasBrotliSupport ? ['br', 'gzip'] : ['gzip']
 
-var encodingSupported = ['gzip', 'deflate', 'identity', 'br']
+var SUPPORTED_ENCODING = (function () {
+  var supported = ['gzip', 'deflate', 'identity']
+  if (hasZstdSupport) supported.unshift('zstd')
+  if (hasBrotliSupport) supported.unshift('br')
+  return supported
+})()
+
+var PREFERRED_ENCODING = (function () {
+  var preferred = ['gzip']
+  if (hasZstdSupport) preferred.unshift('zstd') // prefer zstd over gzip
+  if (hasBrotliSupport) preferred.unshift('br') // prefer br over zstd or gzip
+  return preferred
+})()
+
+var encodingSupported = ['gzip', 'deflate', 'identity', 'br', 'zstd']
 
 /**
  * Compress response data with gzip / deflate.
@@ -57,6 +75,7 @@ var encodingSupported = ['gzip', 'deflate', 'identity', 'br']
 function compression (options) {
   var opts = options || {}
   var optsBrotli = {}
+  var optsZstd = {}
 
   if (hasBrotliSupport) {
     Object.assign(optsBrotli, opts.brotli)
@@ -68,6 +87,10 @@ function compression (options) {
     optsBrotli.params = Object.assign(brotliParams, optsBrotli.params)
   }
 
+  if (hasZstdSupport) {
+    Object.assign(optsZstd, opts.zstd)
+  }
+
   // options
   var filter = opts.filter || shouldCompress
   var threshold = bytes.parse(opts.threshold)
@@ -215,7 +238,9 @@ function compression (options) {
         ? zlib.createGzip(opts)
         : method === 'br'
           ? zlib.createBrotliCompress(optsBrotli)
-          : zlib.createDeflate(opts)
+          : method === 'zstd'
+            ? zlib.createZstdCompress(optsZstd)
+            : zlib.createDeflate(opts)
 
       // add buffered listeners to stream
       addListeners(stream, stream.on, listeners)

package.json

@@ -12,7 +12,7 @@
     "type": "opencollective",
     "url": "https://opencollective.com/express"
   },
-  "keywords": ["compression", "gzip", "deflate", "middleware", "express", "brotli", "http", "stream"],
+  "keywords": ["compression", "gzip", "deflate", "middleware", "express", "brotli", "zstd", "http", "stream"],
   "dependencies": {
     "bytes": "3.1.2",
     "compressible": "~2.0.18",

test/compression.js

@@ -26,6 +26,13 @@ var compression = require('..')
 var hasBrotliSupport = 'createBrotliCompress' in zlib
 var brotli = hasBrotliSupport ? it : it.skip
 
+/**
+ * @const
+ * whether current node version has zstd support
+ */
+var hasZstdSupport = 'createZstdCompress' in zlib
+var zstd = hasZstdSupport ? it : it.skip
+
 describe('compression()', function () {
   it('should skip HEAD', function (done) {
     var server = createServer({ threshold: 0 }, function (req, res) {
@@ -563,6 +570,52 @@ describe('compression()', function () {
     })
   })
 
+  describe('when "Accept-Encoding: zstd"', function () {
+    zstd('should respond with zstd', function (done) {
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'zstd')
+        .expect('Content-Encoding', 'zstd', done)
+    })
+  })
+
+  describe('when "Accept-Encoding: zstd" and passing compression level', function () {
+    zstd('should respond with zstd', function (done) {
+      var params = {}
+      params[zlib.constants.ZSTD_c_compressionLevel] = 10
+
+      var server = createServer({ threshold: 0, zstd: { params: params } }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'zstd')
+        .expect('Content-Encoding', 'zstd', done)
+    })
+
+    zstd('shouldn\'t break compression when gzip is requested', function (done) {
+      var params = {}
+      params[zlib.constants.ZSTD_c_compressionLevel] = 9
+
+      var server = createServer({ threshold: 0, zstd: { params: params } }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'gzip')
+        .expect('Content-Encoding', 'gzip', done)
+    })
+  })
+
   describe('when "Accept-Encoding: gzip, deflate"', function () {
     it('should respond with gzip', function (done) {
       var server = createServer({ threshold: 0 }, function (req, res) {
@@ -634,6 +687,20 @@ describe('compression()', function () {
     })
   })
 
+  describe('when "Accept-Encoding: deflate, gzip, br, zstd"', function () {
+    brotli('should respond with br', function (done) {
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'deflate, gzip, br, zstd')
+        .expect('Content-Encoding', 'br', done)
+    })
+  })
+
   describe('when "Accept-Encoding: gzip;q=1, br;q=0.3"', function () {
     brotli('should respond with gzip', function (done) {
       var server = createServer({ threshold: 0 }, function (req, res) {
@@ -648,6 +715,20 @@ describe('compression()', function () {
     })
   })
 
+  describe('when "Accept-Encoding: gzip;q=1, br;q=0.3, zstd;q=0.5"', function () {
+    it('should respond with gzip', function (done) {
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'gzip;q=1, br;q=0.3, zstd;q=0.5')
+        .expect('Content-Encoding', 'gzip', done)
+    })
+  })
+
   describe('when "Accept-Encoding: gzip, br;q=0.8"', function () {
     brotli('should respond with gzip', function (done) {
       var server = createServer({ threshold: 0 }, function (req, res) {
@@ -662,6 +743,62 @@ describe('compression()', function () {
     })
   })
 
+  describe('when "Accept-Encoding: gzip, br;q=0.8, zstd;q=0.9"', function () {
+    it('should respond with gzip', function (done) {
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'gzip, br;q=0.8, zstd;q=0.9')
+        .expect('Content-Encoding', 'gzip', done)
+    })
+  })
+
+  describe('when "Accept-Encoding: gzip;q=0.2, br;q=0.8, zstd;q=0.6"', function () {
+    brotli('should respond with brotli', function (done) {
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'gzip;q=0.2, br;q=0.8, zstd;q=0.6')
+        .expect('Content-Encoding', 'br', done)
+    })
+  })
+
+  describe('when "Accept-Encoding: gzip;q=0.2, br;q=0.4, zstd;q=0.6"', function () {
+    zstd('should respond with zstd', function (done) {
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'gzip;q=0.2, br;q=0.4, zstd;q=0.6')
+        .expect('Content-Encoding', 'zstd', done)
+    })
+  })
+
+  describe('when "Accept-Encoding: gzip;q=0.1, br;q=0.2, zstd"', function () {
+    zstd('should respond with zstd', function (done) {
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'gzip;q=0.1, br;q=0.2, zstd')
+        .expect('Content-Encoding', 'zstd', done)
+    })
+  })
+
   describe('when "Accept-Encoding: gzip;q=0.001"', function () {
     brotli('should respond with gzip', function (done) {
       var server = createServer({ threshold: 0 }, function (req, res) {
@@ -690,6 +827,20 @@ describe('compression()', function () {
     })
   })
 
+  describe('when "Accept-Encoding: deflate, zstd"', function () {
+    zstd('should respond with zstd', function (done) {
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'deflate, zstd')
+        .expect('Content-Encoding', 'zstd', done)
+    })
+  })
+
   describe('when "Cache-Control: no-transform" response header', function () {
     it('should not compress response', function (done) {
       var server = createServer({ threshold: 0 }, function (req, res) {
@@ -854,6 +1005,32 @@ describe('compression()', function () {
         .end()
     })
 
+    zstd('should flush small chunks for zstd', function (done) {
+      var chunks = 0
+      var next
+      var server = createServer({ threshold: 0 }, function (req, res) {
+        next = writeAndFlush(res, 2, Buffer.from('..'))
+        res.setHeader('Content-Type', 'text/plain')
+        next()
+      })
+
+      function onchunk (chunk) {
+        assert.ok(chunks++ < 20)
+        assert.strictEqual(chunk.toString(), '..')
+        next()
+      }
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', 'zstd')
+        .request()
+        .on('response', unchunk('zstd', onchunk, function (err) {
+          if (err) return done(err)
+          server.close(done)
+        }))
+        .end()
+    })
+
     it('should flush small chunks for deflate', function (done) {
       var chunks = 0
       var next
@@ -947,6 +1124,19 @@ describe('compression()', function () {
         .expect(200, done)
     })
 
+    zstd('should compress when enforceEncoding is zstd', function (done) {
+      var server = createServer({ threshold: 0, enforceEncoding: 'zstd' }, function (req, res) {
+        res.setHeader('Content-Type', 'text/plain')
+        res.end('hello, world')
+      })
+
+      request(server)
+        .get('/')
+        .set('Accept-Encoding', '')
+        .expect('Content-Encoding', 'zstd')
+        .expect(200, done)
+    })
+
     it('should not compress when enforceEncoding is unknown', function (done) {
       var server = createServer({ threshold: 0, enforceEncoding: 'bogus' }, function (req, res) {
         res.setHeader('Content-Type', 'text/plain')
@@ -1070,6 +1260,9 @@ function unchunk (encoding, onchunk, onend) {
       case 'br':
         stream = res.pipe(zlib.createBrotliDecompress())
         break
+      case 'zstd':
+        stream = res.pipe(zlib.createZstdDecompress())
+        break
     }
 
     stream.on('data', onchunk)