fix: support truncated gzip (nodejs#2126)

Author: jimmywarting

lib/fetch/index.js

@@ -2007,7 +2007,14 @@ async function httpNetworkFetch (
             for (const coding of codings) {
               // https://www.rfc-editor.org/rfc/rfc9112.html#section-7.2
               if (coding === 'x-gzip' || coding === 'gzip') {
-                decoders.push(zlib.createGunzip())
+                decoders.push(zlib.createGunzip({
+                  // Be less strict when decoding compressed responses, since sometimes
+                  // servers send slightly invalid responses that are still accepted
+                  // by common browsers.
+                  // Always using Z_SYNC_FLUSH is what cURL does.
+                  flush: zlib.constants.Z_SYNC_FLUSH,
+                  finishFlush: zlib.constants.Z_SYNC_FLUSH
+                }))
               } else if (coding === 'deflate') {
                 decoders.push(zlib.createInflate())
               } else if (coding === 'br') {

test/node-fetch/main.js

@@ -640,15 +640,13 @@ describe('node-fetch', () => {
     })
   })
 
-  xit('should decompress slightly invalid gzip response', () => {
+  it('should decompress slightly invalid gzip response', async () => {
     const url = `${base}gzip-truncated`
-    return fetch(url).then(res => {
-      expect(res.headers.get('content-type')).to.equal('text/plain')
-      return res.text().then(result => {
-        expect(result).to.be.a('string')
-        expect(result).to.equal('hello world')
-      })
-    })
+    const res = await fetch(url)
+    expect(res.headers.get('content-type')).to.equal('text/plain')
+    const result = await res.text()
+    expect(result).to.be.a('string')
+    expect(result).to.equal('hello world')
   })
 
   it('should decompress deflate response', () => {