feat: add decompress interceptor

index.js

@@ -41,7 +41,8 @@ module.exports.createRedirectInterceptor = createRedirectInterceptor
 module.exports.interceptors = {
   redirect: require('./lib/interceptor/redirect'),
   retry: require('./lib/interceptor/retry'),
-  dump: require('./lib/interceptor/dump')
+  dump: require('./lib/interceptor/dump'),
+  decompress: require('./lib/interceptor/decompress')
 }
 
 module.exports.buildConnector = buildConnector

lib/interceptor/decompress.js

@@ -0,0 +1,131 @@
+'use strict'
+
+const util = require('../core/util')
+const DecoratorHandler = require('../handler/decorator-handler')
+const zlib = require('node:zlib')
+const { pipeline, finished } = require('node:stream')
+const { createInflate } = require('../web/fetch/util')
+
+const nullBodyStatus = [101, 204, 205, 304]
+
+class DecompressHandler extends DecoratorHandler {
+  #handler
+  #opts
+
+  #inputStream = null
+  #trailers = null
+
+  constructor (opts, handler) {
+    super(handler)
+    this.#handler = handler
+    this.#opts = opts
+  }
+
+  onConnect (abort) {
+    this.#inputStream = null
+    this.#trailers = null
+    return this.#handler.onConnect(abort)
+  }
+
+  #onDecompressStreamFinished (err) {
+    if (err) {
+      this.#handler.onError(err)
+    } else {
+      this.#handler.onComplete(this.#trailers)
+    }
+  }
+
+  onHeaders (statusCode, rawHeaders, resume, statusMessage) {
+    const parsedHeaders = util.parseHeaders(rawHeaders)
+    const contentEncoding = parsedHeaders['content-encoding']
+    const requestEncodings = contentEncoding ? contentEncoding.split(',').map(e => e.trim().toLowerCase()) : []
+
+    const { method } = this.#opts
+
+    // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Encoding
+    if (requestEncodings.length !== 0 && method !== 'HEAD' && method !== 'CONNECT' && !nullBodyStatus.includes(statusCode)) {
+      const decoders = []
+      for (let i = 0; i < requestEncodings.length; ++i) {
+        const requestEncoding = requestEncodings[i]
+        // https://www.rfc-editor.org/rfc/rfc9112.html#section-7.2
+        if ((requestEncoding === 'x-gzip' || requestEncoding === 'gzip')) {
+          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 (requestEncoding === 'deflate') {
+          decoders.push(createInflate())
+        } else if (requestEncoding === 'br') {
+          decoders.push(zlib.createBrotliDecompress())
+        } else {
+          decoders.length = 0
+          break
+        }
+      }
+
+      if (decoders.length !== 0) {
+        const [firstDecoder, ...restDecoders] = decoders
+        this.#inputStream = firstDecoder
+        let outputStream = firstDecoder
+
+        if (restDecoders.length !== 0) {
+          outputStream = pipeline(
+            this.#inputStream,
+            ...restDecoders,
+            this.#onDecompressStreamFinished.bind(this)
+          )
+        } else {
+          finished(
+            this.#inputStream,
+            this.#onDecompressStreamFinished.bind(this)
+          )
+        }
+
+        outputStream.on('data', (chunk) => {
+          if (!this.#handler.onData(chunk)) {
+            this.#inputStream.pause()
+            this.#inputStream.once('drain', () => this.#inputStream.resume())
+          }
+        })
+      }
+    }
+
+    return this.#handler.onHeaders(
+      statusCode,
+      rawHeaders,
+      resume,
+      statusMessage
+    )
+  }
+
+  onData (chunk) {
+    if (this.#inputStream) {
+      return this.#inputStream.write(chunk)
+    }
+    return this.#handler.onData(chunk)
+  }
+
+  onComplete (trailers) {
+    if (this.#inputStream) {
+      this.#trailers = trailers
+      this.#inputStream.end()
+      return
+    }
+
+    return this.#handler.onComplete(trailers)
+  }
+}
+
+function createDecompressionInterceptor () {
+  return dispatch => {
+    return function Decompress (opts, handler) {
+      return dispatch(opts, new DecompressHandler(opts, handler))
+    }
+  }
+}
+
+module.exports = createDecompressionInterceptor