deno/ext/fetch/23_response.js

// Copyright 2018-2025 the Deno authors. MIT license.

// @ts-check
/// <reference path="../webidl/internal.d.ts" />
/// <reference path="../web/internal.d.ts" />
/// <reference path="../url/internal.d.ts" />
/// <reference path="../../cli/tsc/dts/lib.deno_web.d.ts" />
/// <reference path="./internal.d.ts" />
/// <reference path="../web/06_streams_types.d.ts" />
/// <reference path="../../cli/tsc/dts/lib.deno_fetch.d.ts" />
/// <reference lib="esnext" />

import { core, primordials } from "ext:core/mod.js";
import * as webidl from "ext:deno_webidl/00_webidl.js";
import { createFilteredInspectProxy } from "ext:deno_console/01_console.js";
import {
  byteLowerCase,
  HTTP_TAB_OR_SPACE,
  regexMatcher,
  serializeJSValueToJSONString,
} from "ext:deno_web/00_infra.js";
import { extractBody, mixinBody } from "ext:deno_fetch/22_body.js";
import { getLocationHref } from "ext:deno_web/12_location.js";
import { extractMimeType } from "ext:deno_web/01_mimesniff.js";
import { URL } from "ext:deno_url/00_url.js";
import {
  fillHeaders,
  getDecodeSplitHeader,
  guardFromHeaders,
  headerListFromHeaders,
  headersFromHeaderList,
} from "ext:deno_fetch/20_headers.js";
const {
  ArrayPrototypeMap,
  ArrayPrototypePush,
  ObjectDefineProperties,
  ObjectPrototypeIsPrototypeOf,
  RangeError,
  RegExpPrototypeExec,
  SafeArrayIterator,
  SafeRegExp,
  Symbol,
  SymbolFor,
  TypeError,
} = primordials;

const VCHAR = ["\x21-\x7E"];
const OBS_TEXT = ["\x80-\xFF"];

const REASON_PHRASE = [
  ...new SafeArrayIterator(HTTP_TAB_OR_SPACE),
  ...new SafeArrayIterator(VCHAR),
  ...new SafeArrayIterator(OBS_TEXT),
];
const REASON_PHRASE_MATCHER = regexMatcher(REASON_PHRASE);
const REASON_PHRASE_RE = new SafeRegExp(`^[${REASON_PHRASE_MATCHER}]*$`);

const _response = Symbol("response");
const _headers = Symbol("headers");
const _mimeType = Symbol("mime type");
const _body = Symbol("body");
const _brand = webidl.brand;

// it's slightly faster to cache these
const webidlConvertersBodyInitDomString =
  webidl.converters["BodyInit_DOMString?"];
const webidlConvertersUSVString = webidl.converters["USVString"];
const webidlConvertersUnsignedShort = webidl.converters["unsigned short"];
const webidlConvertersAny = webidl.converters["any"];
const webidlConvertersByteString = webidl.converters["ByteString"];
const webidlConvertersHeadersInit = webidl.converters["HeadersInit"];

/**
 * @typedef InnerResponse
 * @property {"basic" | "cors" | "default" | "error" | "opaque" | "opaqueredirect"} type
 * @property {() => string | null} url
 * @property {string[]} urlList
 * @property {number} status
 * @property {string} statusMessage
 * @property {[string, string][]} headerList
 * @property {null | typeof __window.bootstrap.fetchBody.InnerBody} body
 * @property {boolean} aborted
 * @property {string} [error]
 */

/**
 * @param {number} status
 * @returns {boolean}
 */
function nullBodyStatus(status) {
  return status === 101 || status === 204 || status === 205 || status === 304;
}

/**
 * @param {number} status
 * @returns {boolean}
 */
function redirectStatus(status) {
  return status === 301 || status === 302 || status === 303 ||
    status === 307 || status === 308;
}

/**
 * https://fetch.spec.whatwg.org/#concept-response-clone
 * @param {InnerResponse} response
 * @returns {InnerResponse}
 */
function cloneInnerResponse(response) {
  const urlList = [...new SafeArrayIterator(response.urlList)];
  const headerList = ArrayPrototypeMap(
    response.headerList,
    (x) => [x[0], x[1]],
  );

  let body = null;
  if (response.body !== null) {
    body = response.body.clone();
  }

  return {
    type: response.type,
    body,
    headerList,
    urlList,
    status: response.status,
    statusMessage: response.statusMessage,
    aborted: response.aborted,
    url() {
      if (this.urlList.length == 0) return null;
      return this.urlList[this.urlList.length - 1];
    },
  };
}

/**
 * @returns {InnerResponse}
 */
function newInnerResponse(status = 200, statusMessage = "") {
  return {
    type: "default",
    body: null,
    headerList: [],
    urlList: [],
    status,
    statusMessage,
    aborted: false,
    url() {
      if (this.urlList.length == 0) return null;
      return this.urlList[this.urlList.length - 1];
    },
  };
}

/**
 * @param {string} error
 * @returns {InnerResponse}
 */
function networkError(error) {
  const resp = newInnerResponse(0);
  resp.type = "error";
  resp.error = error;
  return resp;
}

/**
 * @returns {InnerResponse}
 */
function abortedNetworkError() {
  const resp = networkError("aborted");
  resp.aborted = true;
  return resp;
}

/**
 * https://fetch.spec.whatwg.org#initialize-a-response
 * @param {Response} response
 * @param {ResponseInit} init
 * @param {{ body: fetchBody.InnerBody, contentType: string | null } | null} bodyWithType
 */
function initializeAResponse(response, init, bodyWithType) {
  // 1.
  if ((init.status < 200 || init.status > 599) && init.status != 101) {
    throw new RangeError(
      `The status provided (${init.status}) is not equal to 101 and outside the range [200, 599]`,
    );
  }

  // 2.
  if (
    init.statusText &&
    RegExpPrototypeExec(REASON_PHRASE_RE, init.statusText) === null
  ) {
    throw new TypeError(
      `Invalid status text: "${init.statusText}"`,
    );
  }

  // 3.
  response[_response].status = init.status;

  // 4.
  response[_response].statusMessage = init.statusText;
  // 5.
  /** @type {headers.Headers} */
  const headers = response[_headers];
  if (init.headers) {
    fillHeaders(headers, init.headers);
  }

  // 6.
  if (bodyWithType !== null) {
    if (nullBodyStatus(response[_response].status)) {
      throw new TypeError(
        "Response with null body status cannot have body",
      );
    }

    const { body, contentType } = bodyWithType;
    response[_response].body = body;

    if (contentType !== null) {
      let hasContentType = false;
      const list = headerListFromHeaders(headers);
      for (let i = 0; i < list.length; i++) {
        if (byteLowerCase(list[i][0]) === "content-type") {
          hasContentType = true;
          break;
        }
      }
      if (!hasContentType) {
        ArrayPrototypePush(list, ["Content-Type", contentType]);
      }
    }
  }
}

class Response {
  get [_mimeType]() {
    const values = getDecodeSplitHeader(
      headerListFromHeaders(this[_headers]),
      "Content-Type",
    );
    return extractMimeType(values);
  }
  get [_body]() {
    return this[_response].body;
  }

  /**
   * @returns {Response}
   */
  static error() {
    const inner = newInnerResponse(0);
    inner.type = "error";
    const response = webidl.createBranded(Response);
    response[_response] = inner;
    response[_headers] = headersFromHeaderList(
      response[_response].headerList,
      "immutable",
    );
    return response;
  }

  /**
   * @param {string} url
   * @param {number} status
   * @returns {Response}
   */
  static redirect(url, status = 302) {
    const prefix = "Failed to execute 'Response.redirect'";
    url = webidlConvertersUSVString(url, prefix, "Argument 1");
    status = webidlConvertersUnsignedShort(status, prefix, "Argument 2");

    const baseURL = getLocationHref();
    const parsedURL = new URL(url, baseURL);
    if (!redirectStatus(status)) {
      throw new RangeError(`Invalid redirect status code: ${status}`);
    }
    const inner = newInnerResponse(status);
    inner.type = "default";
    ArrayPrototypePush(inner.headerList, ["Location", parsedURL.href]);
    const response = webidl.createBranded(Response);
    response[_response] = inner;
    response[_headers] = headersFromHeaderList(
      response[_response].headerList,
      "immutable",
    );
    return response;
  }

  /**
   * @param {any} data
   * @param {ResponseInit} init
   * @returns {Response}
   */
  static json(data = undefined, init = { __proto__: null }) {
    const prefix = "Failed to execute 'Response.json'";
    data = webidlConvertersAny(data);
    init = webidlConvertersResponseInitFast(init, prefix, "Argument 2");

    const str = serializeJSValueToJSONString(data);
    const res = extractBody(str);
    res.contentType = "application/json";
    const response = webidl.createBranded(Response);
    response[_response] = newInnerResponse();
    response[_headers] = headersFromHeaderList(
      response[_response].headerList,
      "response",
    );
    initializeAResponse(response, init, res);
    return response;
  }

  /**
   * @param {BodyInit | null} body
   * @param {ResponseInit} init
   */
  constructor(body = null, init = undefined) {
    if (body === _brand) {
      this[_brand] = _brand;
      return;
    }

    const prefix = "Failed to construct 'Response'";
    body = webidlConvertersBodyInitDomString(body, prefix, "Argument 1");
    init = webidlConvertersResponseInitFast(init, prefix, "Argument 2");

    this[_response] = newInnerResponse();
    this[_headers] = headersFromHeaderList(
      this[_response].headerList,
      "response",
    );

    let bodyWithType = null;
    if (body !== null) {
      bodyWithType = extractBody(body);
    }
    initializeAResponse(this, init, bodyWithType);
    this[_brand] = _brand;
  }

  /**
   * @returns {"basic" | "cors" | "default" | "error" | "opaque" | "opaqueredirect"}
   */
  get type() {
    webidl.assertBranded(this, ResponsePrototype);
    return this[_response].type;
  }

  /**
   * @returns {string}
   */
  get url() {
    webidl.assertBranded(this, ResponsePrototype);
    const url = this[_response].url();
    if (url === null) return "";
    const newUrl = new URL(url);
    newUrl.hash = "";
    return newUrl.href;
  }

  /**
   * @returns {boolean}
   */
  get redirected() {
    webidl.assertBranded(this, ResponsePrototype);
    return this[_response].urlList.length > 1;
  }

  /**
   * @returns {number}
   */
  get status() {
    webidl.assertBranded(this, ResponsePrototype);
    return this[_response].status;
  }

  /**
   * @returns {boolean}
   */
  get ok() {
    webidl.assertBranded(this, ResponsePrototype);
    const status = this[_response].status;
    return status >= 200 && status <= 299;
  }

  /**
   * @returns {string}
   */
  get statusText() {
    webidl.assertBranded(this, ResponsePrototype);
    return this[_response].statusMessage;
  }

  /**
   * @returns {Headers}
   */
  get headers() {
    webidl.assertBranded(this, ResponsePrototype);
    return this[_headers];
  }

  /**
   * @returns {Response}
   */
  clone() {
    webidl.assertBranded(this, ResponsePrototype);
    if (this[_body] && this[_body].unusable()) {
      throw new TypeError("Body is unusable");
    }
    const second = webidl.createBranded(Response);
    const newRes = cloneInnerResponse(this[_response]);
    second[_response] = newRes;
    second[_headers] = headersFromHeaderList(
      newRes.headerList,
      guardFromHeaders(this[_headers]),
    );
    return second;
  }

  [SymbolFor("Deno.privateCustomInspect")](inspect, inspectOptions) {
    return inspect(
      createFilteredInspectProxy({
        object: this,
        evaluate: ObjectPrototypeIsPrototypeOf(ResponsePrototype, this),
        keys: [
          "body",
          "bodyUsed",
          "headers",
          "ok",
          "redirected",
          "status",
          "statusText",
          "url",
        ],
      }),
      inspectOptions,
    );
  }
}

webidl.configureInterface(Response);
ObjectDefineProperties(Response, {
  json: { __proto__: null, enumerable: true },
  redirect: { __proto__: null, enumerable: true },
  error: { __proto__: null, enumerable: true },
});
const ResponsePrototype = Response.prototype;
mixinBody(ResponsePrototype, _body, _mimeType);

webidl.converters["Response"] = webidl.createInterfaceConverter(
  "Response",
  ResponsePrototype,
);
const webidlConvertersResponseInit = webidl.converters["ResponseInit"] = webidl
  .createDictionaryConverter(
    "ResponseInit",
    [{
      key: "status",
      defaultValue: 200,
      converter: webidlConvertersUnsignedShort,
    }, {
      key: "statusText",
      defaultValue: "",
      converter: webidlConvertersByteString,
    }, {
      key: "headers",
      converter: webidlConvertersHeadersInit,
    }],
  );
const webidlConvertersResponseInitFast = webidl
  .converters["ResponseInit_fast"] = function (
    init,
    prefix,
    context,
    opts,
  ) {
    if (init === undefined || init === null) {
      return { status: 200, statusText: "", headers: undefined };
    }
    // Fast path, if not a proxy
    if (typeof init === "object" && !core.isProxy(init)) {
      // Not a proxy fast path
      const status = init.status !== undefined
        ? webidlConvertersUnsignedShort(init.status)
        : 200;
      const statusText = init.statusText !== undefined
        ? webidlConvertersByteString(init.statusText)
        : "";
      const headers = init.headers !== undefined
        ? webidlConvertersHeadersInit(init.headers)
        : undefined;
      return { status, statusText, headers };
    }
    // Slow default path
    return webidlConvertersResponseInit(init, prefix, context, opts);
  };

/**
 * @param {Response} response
 * @returns {InnerResponse}
 */
function toInnerResponse(response) {
  return response[_response];
}

/**
 * @param {InnerResponse} inner
 * @param {"request" | "immutable" | "request-no-cors" | "response" | "none"} guard
 * @returns {Response}
 */
function fromInnerResponse(inner, guard) {
  const response = new Response(_brand);
  response[_response] = inner;
  response[_headers] = headersFromHeaderList(inner.headerList, guard);
  return response;
}

export {
  abortedNetworkError,
  fromInnerResponse,
  networkError,
  newInnerResponse,
  nullBodyStatus,
  redirectStatus,
  Response,
  ResponsePrototype,
  toInnerResponse,
};