1 files changed, 370 insertions, 0 deletions
diff --git a/cli/rt/26_fetch.js b/cli/rt/26_fetch.js
new file mode 100644
index 000000000..2aee7c457
--- /dev/null
+++ b/cli/rt/26_fetch.js
@@ -0,0 +1,370 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+((window) => {
+  const { notImplemented } = window.__bootstrap.util;
+  const { getHeaderValueParams, isTypedArray } = window.__bootstrap.webUtil;
+  const { Blob, bytesSymbol: blobBytesSymbol } = window.__bootstrap.blob;
+  const { read } = window.__bootstrap.io;
+  const { close } = window.__bootstrap.resources;
+  const { sendAsync } = window.__bootstrap.dispatchJson;
+  const Body = window.__bootstrap.body;
+  const { ReadableStream } = window.__bootstrap.streams;
+  const { MultipartBuilder } = window.__bootstrap.multipart;
+  const { Headers } = window.__bootstrap.headers;
+
+  function opFetch(
+    args,
+    body,
+  ) {
+    let zeroCopy;
+    if (body != null) {
+      zeroCopy = new Uint8Array(body.buffer, body.byteOffset, body.byteLength);
+    }
+
+    return sendAsync("op_fetch", args, ...(zeroCopy ? [zeroCopy] : []));
+  }
+
+  const NULL_BODY_STATUS = [101, 204, 205, 304];
+  const REDIRECT_STATUS = [301, 302, 303, 307, 308];
+
+  const responseData = new WeakMap();
+  class Response extends Body.Body {
+    constructor(body = null, init) {
+      init = init ?? {};
+
+      if (typeof init !== "object") {
+        throw new TypeError(`'init' is not an object`);
+      }
+
+      const extraInit = responseData.get(init) || {};
+      let { type = "default", url = "" } = extraInit;
+
+      let status = init.status === undefined ? 200 : Number(init.status || 0);
+      let statusText = init.statusText ?? "";
+      let headers = init.headers instanceof Headers
+        ? init.headers
+        : new Headers(init.headers);
+
+      if (init.status !== undefined && (status < 200 || status > 599)) {
+        throw new RangeError(
+          `The status provided (${init.status}) is outside the range [200, 599]`,
+        );
+      }
+
+      // null body status
+      if (body && NULL_BODY_STATUS.includes(status)) {
+        throw new TypeError("Response with null body status cannot have body");
+      }
+
+      if (!type) {
+        type = "default";
+      } else {
+        if (type == "error") {
+          // spec: https://fetch.spec.whatwg.org/#concept-network-error
+          status = 0;
+          statusText = "";
+          headers = new Headers();
+          body = null;
+          /* spec for other Response types:
+           https://fetch.spec.whatwg.org/#concept-filtered-response-basic
+           Please note that type "basic" is not the same thing as "default".*/
+        } else if (type == "basic") {
+          for (const h of headers) {
+            /* Forbidden Response-Header Names:
+             https://fetch.spec.whatwg.org/#forbidden-response-header-name */
+            if (["set-cookie", "set-cookie2"].includes(h[0].toLowerCase())) {
+              headers.delete(h[0]);
+            }
+          }
+        } else if (type == "cors") {
+          /* CORS-safelisted Response-Header Names:
+             https://fetch.spec.whatwg.org/#cors-safelisted-response-header-name */
+          const allowedHeaders = [
+            "Cache-Control",
+            "Content-Language",
+            "Content-Length",
+            "Content-Type",
+            "Expires",
+            "Last-Modified",
+            "Pragma",
+          ].map((c) => c.toLowerCase());
+          for (const h of headers) {
+            /* Technically this is still not standards compliant because we are
+             supposed to allow headers allowed in the
+             'Access-Control-Expose-Headers' header in the 'internal response'
+             However, this implementation of response doesn't seem to have an
+             easy way to access the internal response, so we ignore that
+             header.
+             TODO(serverhiccups): change how internal responses are handled
+             so we can do this properly. */
+            if (!allowedHeaders.includes(h[0].toLowerCase())) {
+              headers.delete(h[0]);
+            }
+          }
+          /* TODO(serverhiccups): Once I fix the 'internal response' thing,
+           these actually need to treat the internal response differently */
+        } else if (type == "opaque" || type == "opaqueredirect") {
+          url = "";
+          status = 0;
+          statusText = "";
+          headers = new Headers();
+          body = null;
+        }
+      }
+
+      const contentType = headers.get("content-type") || "";
+      const size = Number(headers.get("content-length")) || undefined;
+
+      super(body, { contentType, size });
+
+      this.url = url;
+      this.statusText = statusText;
+      this.status = extraInit.status || status;
+      this.headers = headers;
+      this.redirected = extraInit.redirected || false;
+      this.type = type;
+    }
+
+    get ok() {
+      return 200 <= this.status && this.status < 300;
+    }
+
+    clone() {
+      if (this.bodyUsed) {
+        throw TypeError(Body.BodyUsedError);
+      }
+
+      const iterators = this.headers.entries();
+      const headersList = [];
+      for (const header of iterators) {
+        headersList.push(header);
+      }
+
+      let resBody = this._bodySource;
+
+      if (this._bodySource instanceof ReadableStream) {
+        const tees = this._bodySource.tee();
+        this._stream = this._bodySource = tees[0];
+        resBody = tees[1];
+      }
+
+      return new Response(resBody, {
+        status: this.status,
+        statusText: this.statusText,
+        headers: new Headers(headersList),
+      });
+    }
+
+    static redirect(url, status) {
+      if (![301, 302, 303, 307, 308].includes(status)) {
+        throw new RangeError(
+          "The redirection status must be one of 301, 302, 303, 307 and 308.",
+        );
+      }
+      return new Response(null, {
+        status,
+        statusText: "",
+        headers: [["Location", typeof url === "string" ? url : url.toString()]],
+      });
+    }
+  }
+
+  function sendFetchReq(
+    url,
+    method,
+    headers,
+    body,
+  ) {
+    let headerArray = [];
+    if (headers) {
+      headerArray = Array.from(headers.entries());
+    }
+
+    const args = {
+      method,
+      url,
+      headers: headerArray,
+    };
+
+    return opFetch(args, body);
+  }
+
+  async function fetch(
+    input,
+    init,
+  ) {
+    let url;
+    let method = null;
+    let headers = null;
+    let body;
+    let redirected = false;
+    let remRedirectCount = 20; // TODO: use a better way to handle
+
+    if (typeof input === "string" || input instanceof URL) {
+      url = typeof input === "string" ? input : input.href;
+      if (init != null) {
+        method = init.method || null;
+        if (init.headers) {
+          headers = init.headers instanceof Headers
+            ? init.headers
+            : new Headers(init.headers);
+        } else {
+          headers = null;
+        }
+
+        // ref: https://fetch.spec.whatwg.org/#body-mixin
+        // Body should have been a mixin
+        // but we are treating it as a separate class
+        if (init.body) {
+          if (!headers) {
+            headers = new Headers();
+          }
+          let contentType = "";
+          if (typeof init.body === "string") {
+            body = new TextEncoder().encode(init.body);
+            contentType = "text/plain;charset=UTF-8";
+          } else if (isTypedArray(init.body)) {
+            body = init.body;
+          } else if (init.body instanceof ArrayBuffer) {
+            body = new Uint8Array(init.body);
+          } else if (init.body instanceof URLSearchParams) {
+            body = new TextEncoder().encode(init.body.toString());
+            contentType = "application/x-www-form-urlencoded;charset=UTF-8";
+          } else if (init.body instanceof Blob) {
+            body = init.body[blobBytesSymbol];
+            contentType = init.body.type;
+          } else if (init.body instanceof FormData) {
+            let boundary;
+            if (headers.has("content-type")) {
+              const params = getHeaderValueParams("content-type");
+              boundary = params.get("boundary");
+            }
+            const multipartBuilder = new MultipartBuilder(init.body, boundary);
+            body = multipartBuilder.getBody();
+            contentType = multipartBuilder.getContentType();
+          } else {
+            // TODO: ReadableStream
+            notImplemented();
+          }
+          if (contentType && !headers.has("content-type")) {
+            headers.set("content-type", contentType);
+          }
+        }
+      }
+    } else {
+      url = input.url;
+      method = input.method;
+      headers = input.headers;
+
+      if (input._bodySource) {
+        body = new DataView(await input.arrayBuffer());
+      }
+    }
+
+    let responseBody;
+    let responseInit = {};
+    while (remRedirectCount) {
+      const fetchResponse = await sendFetchReq(url, method, headers, body);
+
+      if (
+        NULL_BODY_STATUS.includes(fetchResponse.status) ||
+        REDIRECT_STATUS.includes(fetchResponse.status)
+      ) {
+        // We won't use body of received response, so close it now
+        // otherwise it will be kept in resource table.
+        close(fetchResponse.bodyRid);
+        responseBody = null;
+      } else {
+        responseBody = new ReadableStream({
+          async pull(controller) {
+            try {
+              const b = new Uint8Array(1024 * 32);
+              const result = await read(fetchResponse.bodyRid, b);
+              if (result === null) {
+                controller.close();
+                return close(fetchResponse.bodyRid);
+              }
+
+              controller.enqueue(b.subarray(0, result));
+            } catch (e) {
+              controller.error(e);
+              controller.close();
+              close(fetchResponse.bodyRid);
+            }
+          },
+          cancel() {
+            // When reader.cancel() is called
+            close(fetchResponse.bodyRid);
+          },
+        });
+      }
+
+      responseInit = {
+        status: 200,
+        statusText: fetchResponse.statusText,
+        headers: fetchResponse.headers,
+      };
+
+      responseData.set(responseInit, {
+        redirected,
+        rid: fetchResponse.bodyRid,
+        status: fetchResponse.status,
+        url,
+      });
+
+      const response = new Response(responseBody, responseInit);
+
+      if (REDIRECT_STATUS.includes(fetchResponse.status)) {
+        // We're in a redirect status
+        switch ((init && init.redirect) || "follow") {
+          case "error":
+            responseInit = {};
+            responseData.set(responseInit, {
+              type: "error",
+              redirected: false,
+              url: "",
+            });
+            return new Response(null, responseInit);
+          case "manual":
+            responseInit = {};
+            responseData.set(responseInit, {
+              type: "opaqueredirect",
+              redirected: false,
+              url: "",
+            });
+            return new Response(null, responseInit);
+          case "follow":
+          default:
+            let redirectUrl = response.headers.get("Location");
+            if (redirectUrl == null) {
+              return response; // Unspecified
+            }
+            if (
+              !redirectUrl.startsWith("http://") &&
+              !redirectUrl.startsWith("https://")
+            ) {
+              redirectUrl = new URL(redirectUrl, url).href;
+            }
+            url = redirectUrl;
+            redirected = true;
+            remRedirectCount--;
+        }
+      } else {
+        return response;
+      }
+    }
+
+    responseData.set(responseInit, {
+      type: "error",
+      redirected: false,
+      url: "",
+    });
+
+    return new Response(null, responseInit);
+  }
+
+  window.__bootstrap.fetch = {
+    fetch,
+    Response,
+  };
+})(this);