Created a first draft of this action. (#14)

Reviewed-on: #14
Co-authored-by: Philipp Horstenkamp <philipp@horstenkamp.de>
Co-committed-by: Philipp Horstenkamp <philipp@horstenkamp.de>

node_modules/undici/lib/handler/DecoratorHandler.js

@@ -0,0 +1,35 @@
+'use strict'
+
+module.exports = class DecoratorHandler {
+  constructor (handler) {
+    this.handler = handler
+  }
+
+  onConnect (...args) {
+    return this.handler.onConnect(...args)
+  }
+
+  onError (...args) {
+    return this.handler.onError(...args)
+  }
+
+  onUpgrade (...args) {
+    return this.handler.onUpgrade(...args)
+  }
+
+  onHeaders (...args) {
+    return this.handler.onHeaders(...args)
+  }
+
+  onData (...args) {
+    return this.handler.onData(...args)
+  }
+
+  onComplete (...args) {
+    return this.handler.onComplete(...args)
+  }
+
+  onBodySent (...args) {
+    return this.handler.onBodySent(...args)
+  }
+}

node_modules/undici/lib/handler/RedirectHandler.js

@@ -0,0 +1,216 @@
+'use strict'
+
+const util = require('../core/util')
+const { kBodyUsed } = require('../core/symbols')
+const assert = require('assert')
+const { InvalidArgumentError } = require('../core/errors')
+const EE = require('events')
+
+const redirectableStatusCodes = [300, 301, 302, 303, 307, 308]
+
+const kBody = Symbol('body')
+
+class BodyAsyncIterable {
+  constructor (body) {
+    this[kBody] = body
+    this[kBodyUsed] = false
+  }
+
+  async * [Symbol.asyncIterator] () {
+    assert(!this[kBodyUsed], 'disturbed')
+    this[kBodyUsed] = true
+    yield * this[kBody]
+  }
+}
+
+class RedirectHandler {
+  constructor (dispatch, maxRedirections, opts, handler) {
+    if (maxRedirections != null && (!Number.isInteger(maxRedirections) || maxRedirections < 0)) {
+      throw new InvalidArgumentError('maxRedirections must be a positive number')
+    }
+
+    util.validateHandler(handler, opts.method, opts.upgrade)
+
+    this.dispatch = dispatch
+    this.location = null
+    this.abort = null
+    this.opts = { ...opts, maxRedirections: 0 } // opts must be a copy
+    this.maxRedirections = maxRedirections
+    this.handler = handler
+    this.history = []
+
+    if (util.isStream(this.opts.body)) {
+      // TODO (fix): Provide some way for the user to cache the file to e.g. /tmp
+      // so that it can be dispatched again?
+      // TODO (fix): Do we need 100-expect support to provide a way to do this properly?
+      if (util.bodyLength(this.opts.body) === 0) {
+        this.opts.body
+          .on('data', function () {
+            assert(false)
+          })
+      }
+
+      if (typeof this.opts.body.readableDidRead !== 'boolean') {
+        this.opts.body[kBodyUsed] = false
+        EE.prototype.on.call(this.opts.body, 'data', function () {
+          this[kBodyUsed] = true
+        })
+      }
+    } else if (this.opts.body && typeof this.opts.body.pipeTo === 'function') {
+      // TODO (fix): We can't access ReadableStream internal state
+      // to determine whether or not it has been disturbed. This is just
+      // a workaround.
+      this.opts.body = new BodyAsyncIterable(this.opts.body)
+    } else if (
+      this.opts.body &&
+      typeof this.opts.body !== 'string' &&
+      !ArrayBuffer.isView(this.opts.body) &&
+      util.isIterable(this.opts.body)
+    ) {
+      // TODO: Should we allow re-using iterable if !this.opts.idempotent
+      // or through some other flag?
+      this.opts.body = new BodyAsyncIterable(this.opts.body)
+    }
+  }
+
+  onConnect (abort) {
+    this.abort = abort
+    this.handler.onConnect(abort, { history: this.history })
+  }
+
+  onUpgrade (statusCode, headers, socket) {
+    this.handler.onUpgrade(statusCode, headers, socket)
+  }
+
+  onError (error) {
+    this.handler.onError(error)
+  }
+
+  onHeaders (statusCode, headers, resume, statusText) {
+    this.location = this.history.length >= this.maxRedirections || util.isDisturbed(this.opts.body)
+      ? null
+      : parseLocation(statusCode, headers)
+
+    if (this.opts.origin) {
+      this.history.push(new URL(this.opts.path, this.opts.origin))
+    }
+
+    if (!this.location) {
+      return this.handler.onHeaders(statusCode, headers, resume, statusText)
+    }
+
+    const { origin, pathname, search } = util.parseURL(new URL(this.location, this.opts.origin && new URL(this.opts.path, this.opts.origin)))
+    const path = search ? `${pathname}${search}` : pathname
+
+    // Remove headers referring to the original URL.
+    // By default it is Host only, unless it's a 303 (see below), which removes also all Content-* headers.
+    // https://tools.ietf.org/html/rfc7231#section-6.4
+    this.opts.headers = cleanRequestHeaders(this.opts.headers, statusCode === 303, this.opts.origin !== origin)
+    this.opts.path = path
+    this.opts.origin = origin
+    this.opts.maxRedirections = 0
+    this.opts.query = null
+
+    // https://tools.ietf.org/html/rfc7231#section-6.4.4
+    // In case of HTTP 303, always replace method to be either HEAD or GET
+    if (statusCode === 303 && this.opts.method !== 'HEAD') {
+      this.opts.method = 'GET'
+      this.opts.body = null
+    }
+  }
+
+  onData (chunk) {
+    if (this.location) {
+      /*
+        https://tools.ietf.org/html/rfc7231#section-6.4
+
+        TLDR: undici always ignores 3xx response bodies.
+
+        Redirection is used to serve the requested resource from another URL, so it is assumes that
+        no body is generated (and thus can be ignored). Even though generating a body is not prohibited.
+
+        For status 301, 302, 303, 307 and 308 (the latter from RFC 7238), the specs mention that the body usually
+        (which means it's optional and not mandated) contain just an hyperlink to the value of
+        the Location response header, so the body can be ignored safely.
+
+        For status 300, which is "Multiple Choices", the spec mentions both generating a Location
+        response header AND a response body with the other possible location to follow.
+        Since the spec explicitily chooses not to specify a format for such body and leave it to
+        servers and browsers implementors, we ignore the body as there is no specified way to eventually parse it.
+      */
+    } else {
+      return this.handler.onData(chunk)
+    }
+  }
+
+  onComplete (trailers) {
+    if (this.location) {
+      /*
+        https://tools.ietf.org/html/rfc7231#section-6.4
+
+        TLDR: undici always ignores 3xx response trailers as they are not expected in case of redirections
+        and neither are useful if present.
+
+        See comment on onData method above for more detailed informations.
+      */
+
+      this.location = null
+      this.abort = null
+
+      this.dispatch(this.opts, this)
+    } else {
+      this.handler.onComplete(trailers)
+    }
+  }
+
+  onBodySent (chunk) {
+    if (this.handler.onBodySent) {
+      this.handler.onBodySent(chunk)
+    }
+  }
+}
+
+function parseLocation (statusCode, headers) {
+  if (redirectableStatusCodes.indexOf(statusCode) === -1) {
+    return null
+  }
+
+  for (let i = 0; i < headers.length; i += 2) {
+    if (headers[i].toString().toLowerCase() === 'location') {
+      return headers[i + 1]
+    }
+  }
+}
+
+// https://tools.ietf.org/html/rfc7231#section-6.4.4
+function shouldRemoveHeader (header, removeContent, unknownOrigin) {
+  return (
+    (header.length === 4 && header.toString().toLowerCase() === 'host') ||
+    (removeContent && header.toString().toLowerCase().indexOf('content-') === 0) ||
+    (unknownOrigin && header.length === 13 && header.toString().toLowerCase() === 'authorization') ||
+    (unknownOrigin && header.length === 6 && header.toString().toLowerCase() === 'cookie')
+  )
+}
+
+// https://tools.ietf.org/html/rfc7231#section-6.4
+function cleanRequestHeaders (headers, removeContent, unknownOrigin) {
+  const ret = []
+  if (Array.isArray(headers)) {
+    for (let i = 0; i < headers.length; i += 2) {
+      if (!shouldRemoveHeader(headers[i], removeContent, unknownOrigin)) {
+        ret.push(headers[i], headers[i + 1])
+      }
+    }
+  } else if (headers && typeof headers === 'object') {
+    for (const key of Object.keys(headers)) {
+      if (!shouldRemoveHeader(key, removeContent, unknownOrigin)) {
+        ret.push(key, headers[key])
+      }
+    }
+  } else {
+    assert(headers == null, 'headers must be an object or an array')
+  }
+  return ret
+}
+
+module.exports = RedirectHandler