1 files changed, 259 insertions, 0 deletions
diff --git a/vanilla/node_modules/undici/lib/interceptor/decompress.js b/vanilla/node_modules/undici/lib/interceptor/decompress.js
new file mode 100644
index 0000000..ee4202a
--- /dev/null
+++ b/vanilla/node_modules/undici/lib/interceptor/decompress.js
@@ -0,0 +1,259 @@
+'use strict'
+
+const { createInflate, createGunzip, createBrotliDecompress, createZstdDecompress } = require('node:zlib')
+const { pipeline } = require('node:stream')
+const DecoratorHandler = require('../handler/decorator-handler')
+const { runtimeFeatures } = require('../util/runtime-features')
+
+/** @typedef {import('node:stream').Transform} Transform */
+/** @typedef {import('node:stream').Transform} Controller */
+/** @typedef {Transform&import('node:zlib').Zlib} DecompressorStream */
+
+/** @type {Record<string, () => DecompressorStream>} */
+const supportedEncodings = {
+  gzip: createGunzip,
+  'x-gzip': createGunzip,
+  br: createBrotliDecompress,
+  deflate: createInflate,
+  compress: createInflate,
+  'x-compress': createInflate,
+  ...(runtimeFeatures.has('zstd') ? { zstd: createZstdDecompress } : {})
+}
+
+const defaultSkipStatusCodes = /** @type {const} */ ([204, 304])
+
+let warningEmitted = /** @type {boolean} */ (false)
+
+/**
+ * @typedef {Object} DecompressHandlerOptions
+ * @property {number[]|Readonly<number[]>} [skipStatusCodes=[204, 304]] - List of status codes to skip decompression for
+ * @property {boolean} [skipErrorResponses] - Whether to skip decompression for error responses (status codes >= 400)
+ */
+
+class DecompressHandler extends DecoratorHandler {
+  /** @type {Transform[]} */
+  #decompressors = []
+  /** @type {Readonly<number[]>} */
+  #skipStatusCodes
+  /** @type {boolean} */
+  #skipErrorResponses
+
+  constructor (handler, { skipStatusCodes = defaultSkipStatusCodes, skipErrorResponses = true } = {}) {
+    super(handler)
+    this.#skipStatusCodes = skipStatusCodes
+    this.#skipErrorResponses = skipErrorResponses
+  }
+
+  /**
+   * Determines if decompression should be skipped based on encoding and status code
+   * @param {string} contentEncoding - Content-Encoding header value
+   * @param {number} statusCode - HTTP status code of the response
+   * @returns {boolean} - True if decompression should be skipped
+   */
+  #shouldSkipDecompression (contentEncoding, statusCode) {
+    if (!contentEncoding || statusCode < 200) return true
+    if (this.#skipStatusCodes.includes(statusCode)) return true
+    if (this.#skipErrorResponses && statusCode >= 400) return true
+    return false
+  }
+
+  /**
+   * Creates a chain of decompressors for multiple content encodings
+   *
+   * @param {string} encodings - Comma-separated list of content encodings
+   * @returns {Array<DecompressorStream>} - Array of decompressor streams
+   * @throws {Error} - If the number of content-encodings exceeds the maximum allowed
+   */
+  #createDecompressionChain (encodings) {
+    const parts = encodings.split(',')
+
+    // Limit the number of content-encodings to prevent resource exhaustion.
+    // CVE fix similar to urllib3 (GHSA-gm62-xv2j-4w53) and curl (CVE-2022-32206).
+    const maxContentEncodings = 5
+    if (parts.length > maxContentEncodings) {
+      throw new Error(`too many content-encodings in response: ${parts.length}, maximum allowed is ${maxContentEncodings}`)
+    }
+
+    /** @type {DecompressorStream[]} */
+    const decompressors = []
+
+    for (let i = parts.length - 1; i >= 0; i--) {
+      const encoding = parts[i].trim()
+      if (!encoding) continue
+
+      if (!supportedEncodings[encoding]) {
+        decompressors.length = 0 // Clear if unsupported encoding
+        return decompressors // Unsupported encoding
+      }
+
+      decompressors.push(supportedEncodings[encoding]())
+    }
+
+    return decompressors
+  }
+
+  /**
+   * Sets up event handlers for a decompressor stream using readable events
+   * @param {DecompressorStream} decompressor - The decompressor stream
+   * @param {Controller} controller - The controller to coordinate with
+   * @returns {void}
+   */
+  #setupDecompressorEvents (decompressor, controller) {
+    decompressor.on('readable', () => {
+      let chunk
+      while ((chunk = decompressor.read()) !== null) {
+        const result = super.onResponseData(controller, chunk)
+        if (result === false) {
+          break
+        }
+      }
+    })
+
+    decompressor.on('error', (error) => {
+      super.onResponseError(controller, error)
+    })
+  }
+
+  /**
+   * Sets up event handling for a single decompressor
+   * @param {Controller} controller - The controller to handle events
+   * @returns {void}
+   */
+  #setupSingleDecompressor (controller) {
+    const decompressor = this.#decompressors[0]
+    this.#setupDecompressorEvents(decompressor, controller)
+
+    decompressor.on('end', () => {
+      super.onResponseEnd(controller, {})
+    })
+  }
+
+  /**
+   * Sets up event handling for multiple chained decompressors using pipeline
+   * @param {Controller} controller - The controller to handle events
+   * @returns {void}
+   */
+  #setupMultipleDecompressors (controller) {
+    const lastDecompressor = this.#decompressors[this.#decompressors.length - 1]
+    this.#setupDecompressorEvents(lastDecompressor, controller)
+
+    pipeline(this.#decompressors, (err) => {
+      if (err) {
+        super.onResponseError(controller, err)
+        return
+      }
+      super.onResponseEnd(controller, {})
+    })
+  }
+
+  /**
+   * Cleans up decompressor references to prevent memory leaks
+   * @returns {void}
+   */
+  #cleanupDecompressors () {
+    this.#decompressors.length = 0
+  }
+
+  /**
+   * @param {Controller} controller
+   * @param {number} statusCode
+   * @param {Record<string, string | string[] | undefined>} headers
+   * @param {string} statusMessage
+   * @returns {void}
+   */
+  onResponseStart (controller, statusCode, headers, statusMessage) {
+    const contentEncoding = headers['content-encoding']
+
+    // If content encoding is not supported or status code is in skip list
+    if (this.#shouldSkipDecompression(contentEncoding, statusCode)) {
+      return super.onResponseStart(controller, statusCode, headers, statusMessage)
+    }
+
+    const decompressors = this.#createDecompressionChain(contentEncoding.toLowerCase())
+
+    if (decompressors.length === 0) {
+      this.#cleanupDecompressors()
+      return super.onResponseStart(controller, statusCode, headers, statusMessage)
+    }
+
+    this.#decompressors = decompressors
+
+    // Remove compression headers since we're decompressing
+    const { 'content-encoding': _, 'content-length': __, ...newHeaders } = headers
+
+    if (this.#decompressors.length === 1) {
+      this.#setupSingleDecompressor(controller)
+    } else {
+      this.#setupMultipleDecompressors(controller)
+    }
+
+    return super.onResponseStart(controller, statusCode, newHeaders, statusMessage)
+  }
+
+  /**
+   * @param {Controller} controller
+   * @param {Buffer} chunk
+   * @returns {void}
+   */
+  onResponseData (controller, chunk) {
+    if (this.#decompressors.length > 0) {
+      this.#decompressors[0].write(chunk)
+      return
+    }
+    super.onResponseData(controller, chunk)
+  }
+
+  /**
+   * @param {Controller} controller
+   * @param {Record<string, string | string[]> | undefined} trailers
+   * @returns {void}
+   */
+  onResponseEnd (controller, trailers) {
+    if (this.#decompressors.length > 0) {
+      this.#decompressors[0].end()
+      this.#cleanupDecompressors()
+      return
+    }
+    super.onResponseEnd(controller, trailers)
+  }
+
+  /**
+   * @param {Controller} controller
+   * @param {Error} err
+   * @returns {void}
+   */
+  onResponseError (controller, err) {
+    if (this.#decompressors.length > 0) {
+      for (const decompressor of this.#decompressors) {
+        decompressor.destroy(err)
+      }
+      this.#cleanupDecompressors()
+    }
+    super.onResponseError(controller, err)
+  }
+}
+
+/**
+ * Creates a decompression interceptor for HTTP responses
+ * @param {DecompressHandlerOptions} [options] - Options for the interceptor
+ * @returns {Function} - Interceptor function
+ */
+function createDecompressInterceptor (options = {}) {
+  // Emit experimental warning only once
+  if (!warningEmitted) {
+    process.emitWarning(
+      'DecompressInterceptor is experimental and subject to change',
+      'ExperimentalWarning'
+    )
+    warningEmitted = true
+  }
+
+  return (dispatch) => {
+    return (opts, handler) => {
+      const decompressHandler = new DecompressHandler(handler, options)
+      return dispatch(opts, decompressHandler)
+    }
+  }
+}
+
+module.exports = createDecompressInterceptor