fix: support deflate raw responses (nodejs#2650)

lib/fetch/index.js

@@ -43,7 +43,8 @@ const {
   urlHasHttpsScheme,
   clampAndCoursenConnectionTimingInfo,
   simpleRangeHeaderValue,
-  buildContentRange
+  buildContentRange,
+  createInflate
 } = require('./util')
 const { kState } = require('./symbols')
 const assert = require('assert')
@@ -1089,7 +1090,7 @@ function fetchFinale (fetchParams, response) {
     // 3. Set up transformStream with transformAlgorithm set to identityTransformAlgorithm and flushAlgorithm
     //    set to processResponseEndOfBody.
     const transformStream = new TransformStream({
-      start () {},
+      start () { },
       transform (chunk, controller) {
         controller.enqueue(chunk)
       },
@@ -2179,7 +2180,7 @@ async function httpNetworkFetch (
                   finishFlush: zlib.constants.Z_SYNC_FLUSH
                 }))
               } else if (coding === 'deflate') {
-                decoders.push(zlib.createInflate())
+                decoders.push(createInflate())
               } else if (coding === 'br') {
                 decoders.push(zlib.createBrotliDecompress())
               } else {
@@ -2195,7 +2196,7 @@ async function httpNetworkFetch (
             headersList,
             body: decoders.length
               ? pipeline(this.body, ...decoders, () => { })
-              : this.body.on('error', () => {})
+              : this.body.on('error', () => { })
           })
 
           return true

lib/fetch/util.js

@@ -1,5 +1,7 @@
 'use strict'
 
+const { Transform } = require('node:stream')
+const zlib = require('node:zlib')
 const { redirectStatusSet, referrerPolicySet: referrerPolicyTokens, badPortsSet } = require('./constants')
 const { getGlobalOrigin } = require('./global')
 const { performance } = require('perf_hooks')
@@ -1174,6 +1176,43 @@ function buildContentRange (rangeStart, rangeEnd, fullLength) {
   return contentRange
 }
 
+// A Stream, which pipes the response to zlib.createInflate() or
+// zlib.createInflateRaw() depending on the first byte of the Buffer.
+// If the lower byte of the first byte is 0x08, then the stream is
+// interpreted as a zlib stream, otherwise it's interpreted as a
+// raw deflate stream.
+class InflateStream extends Transform {
+  _transform (chunk, encoding, callback) {
+    if (!this._inflateStream) {
+      if (chunk.length === 0) {
+        callback()
+        return
+      }
+      this._inflateStream = (chunk[0] & 0x0F) === 0x08
+        ? zlib.createInflate()
+        : zlib.createInflateRaw()
+
+      this._inflateStream.on('data', this.push.bind(this))
+      this._inflateStream.on('end', () => this.push(null))
+      this._inflateStream.on('error', (err) => this.destroy(err))
+    }
+
+    this._inflateStream.write(chunk, encoding, callback)
+  }
+
+  _final (callback) {
+    if (this._inflateStream) {
+      this._inflateStream.end()
+      this._inflateStream = null
+    }
+    callback()
+  }
+}
+
+function createInflate () {
+  return new InflateStream()
+}
+
 module.exports = {
   isAborted,
   isCancelled,
@@ -1221,5 +1260,6 @@ module.exports = {
   normalizeMethodRecord,
   simpleRangeHeaderValue,
   buildContentRange,
-  parseMetadata
+  parseMetadata,
+  createInflate
 }

test/node-fetch/main.js

@@ -659,7 +659,7 @@ describe('node-fetch', () => {
     })
   })
 
-  xit('should decompress deflate raw response from old apache server', () => {
+  it('should decompress deflate raw response from old apache server', () => {
     const url = `${base}deflate-raw`
     return fetch(url).then(res => {
       expect(res.headers.get('content-type')).to.equal('text/plain')