13 files changed, 1054 insertions, 19 deletions
diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index cd2ef0a84..f67158310 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -69,6 +69,8 @@ tempfile = "3.1.0"
 termcolor = "1.1.0"
 tokio = { version = "0.2.22", features = ["full"] }
 tokio-rustls = "0.14.0"
+# Keep in-sync with warp.
+tokio-tungstenite = { version = "0.11.0" }
 url = "2.1.1"
 webpki = "0.21.3"
 webpki-roots = "0.19.0"
@@ -89,8 +91,6 @@ nix = "0.17.0"
 # Used in benchmark
 chrono = "0.4"
 os_pipe = "0.9.2"
-# Used for testing inspector. Keep in-sync with warp.
-tokio-tungstenite = { version = "0.11.0", features = ["connect"] }
 test_util = { path = "../test_util" }
 
 [package.metadata.winres]
diff --git a/cli/dts/lib.deno.shared_globals.d.ts b/cli/dts/lib.deno.shared_globals.d.ts
index a903a0693..8e97fe014 100644
--- a/cli/dts/lib.deno.shared_globals.d.ts
+++ b/cli/dts/lib.deno.shared_globals.d.ts
@@ -595,7 +595,7 @@ declare class Console {
    *
    * Since we write to stdout, we can't display anything interactive
    * we just fall back to `console.dir`.
-   * 
+   *
    * > [Console.dirxml](https://developer.mozilla.org/en-US/docs/Web/API/Console/dirxml)
    * > by Mozilla Contributors is licensed under CC-BY-SA 2.5.
    */
@@ -1436,3 +1436,99 @@ interface ErrorConstructor {
   // TODO(nayeemrmn): Support `Error.prepareStackTrace()`. We currently use this
   // internally in a way that makes it unavailable for users.
 }
+
+interface CloseEventInit extends EventInit {
+  code?: number;
+  reason?: string;
+  wasClean?: boolean;
+}
+
+interface CloseEvent extends Event {
+  /**
+   * Returns the WebSocket connection close code provided by the server.
+   */
+  readonly code: number;
+  /**
+   * Returns the WebSocket connection close reason provided by the server.
+   */
+  readonly reason: string;
+  /**
+   * Returns true if the connection closed cleanly; false otherwise.
+   */
+  readonly wasClean: boolean;
+}
+
+declare var CloseEvent: {
+  prototype: CloseEvent;
+  new(type: string, eventInitDict?: CloseEventInit): CloseEvent;
+};
+
+interface WebSocketEventMap {
+  "close": CloseEvent;
+  "error": Event;
+  "message": MessageEvent;
+  "open": Event;
+}
+
+/** Provides the API for creating and managing a WebSocket connection to a server, as well as for sending and receiving data on the connection. */
+interface WebSocket extends EventTarget {
+  /**
+   * Returns a string that indicates how binary data from the WebSocket object is exposed to scripts:
+   *
+   * Can be set, to change how binary data is returned. The default is "blob".
+   */
+  binaryType: BinaryType;
+  /**
+   * Returns the number of bytes of application data (UTF-8 text and binary data) that have been queued using send() but not yet been transmitted to the network.
+   *
+   * If the WebSocket connection is closed, this attribute's value will only increase with each call to the send() method. (The number does not reset to zero once the connection closes.)
+   */
+  readonly bufferedAmount: number;
+  /**
+   * Returns the extensions selected by the server, if any.
+   */
+  readonly extensions: string;
+  onclose: ((this: WebSocket, ev: CloseEvent) => any) | null;
+  onerror: ((this: WebSocket, ev: Event) => any) | null;
+  onmessage: ((this: WebSocket, ev: MessageEvent) => any) | null;
+  onopen: ((this: WebSocket, ev: Event) => any) | null;
+  /**
+   * Returns the subprotocol selected by the server, if any. It can be used in conjunction with the array form of the constructor's second argument to perform subprotocol negotiation.
+   */
+  readonly protocol: string;
+  /**
+   * Returns the state of the WebSocket object's connection. It can have the values described below.
+   */
+  readonly readyState: number;
+  /**
+   * Returns the URL that was used to establish the WebSocket connection.
+   */
+  readonly url: string;
+  /**
+   * Closes the WebSocket connection, optionally using code as the the WebSocket connection close code and reason as the the WebSocket connection close reason.
+   */
+  close(code?: number, reason?: string): void;
+  /**
+   * Transmits data using the WebSocket connection. data can be a string, a Blob, an ArrayBuffer, or an ArrayBufferView.
+   */
+  send(data: string | ArrayBufferLike | Blob | ArrayBufferView): void;
+  readonly CLOSED: number;
+  readonly CLOSING: number;
+  readonly CONNECTING: number;
+  readonly OPEN: number;
+  addEventListener<K extends keyof WebSocketEventMap>(type: K, listener: (this: WebSocket, ev: WebSocketEventMap[K]) => any, options?: boolean | AddEventListenerOptions): void;
+  addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
+  removeEventListener<K extends keyof WebSocketEventMap>(type: K, listener: (this: WebSocket, ev: WebSocketEventMap[K]) => any, options?: boolean | EventListenerOptions): void;
+  removeEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | EventListenerOptions): void;
+}
+
+declare var WebSocket: {
+  prototype: WebSocket;
+  new(url: string, protocols?: string | string[]): WebSocket;
+  readonly CLOSED: number;
+  readonly CLOSING: number;
+  readonly CONNECTING: number;
+  readonly OPEN: number;
+};
+
+type BinaryType = "arraybuffer" | "blob";
diff --git a/cli/ops/mod.rs b/cli/ops/mod.rs
index f8fcea1b5..bc6b4f377 100644
--- a/cli/ops/mod.rs
+++ b/cli/ops/mod.rs
@@ -33,4 +33,5 @@ pub mod timers;
 pub mod tls;
 pub mod tty;
 pub mod web_worker;
+pub mod websocket;
 pub mod worker_host;
diff --git a/cli/ops/websocket.rs b/cli/ops/websocket.rs
new file mode 100644
index 000000000..126d67861
--- /dev/null
+++ b/cli/ops/websocket.rs
@@ -0,0 +1,288 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+use super::dispatch_json::{Deserialize, JsonOp, Value};
+use crate::state::State;
+use core::task::Poll;
+use deno_core::ErrBox;
+use deno_core::ZeroCopyBuf;
+use deno_core::{CoreIsolate, CoreIsolateState};
+use futures::future::{poll_fn, FutureExt};
+use futures::StreamExt;
+use futures::{ready, SinkExt};
+use http::{Method, Request, Uri};
+use std::borrow::Cow;
+use std::fs::File;
+use std::io::BufReader;
+use std::rc::Rc;
+use std::sync::Arc;
+use tokio::net::TcpStream;
+use tokio_rustls::{rustls::ClientConfig, TlsConnector};
+use tokio_tungstenite::stream::Stream as StreamSwitcher;
+use tokio_tungstenite::tungstenite::{
+  handshake::client::Response, protocol::frame::coding::CloseCode,
+  protocol::CloseFrame, Error, Message,
+};
+use tokio_tungstenite::{client_async, WebSocketStream};
+use webpki::DNSNameRef;
+
+pub fn init(i: &mut CoreIsolate, s: &Rc<State>) {
+  i.register_op("op_ws_create", s.stateful_json_op2(op_ws_create));
+  i.register_op("op_ws_send", s.stateful_json_op2(op_ws_send));
+  i.register_op("op_ws_close", s.stateful_json_op2(op_ws_close));
+  i.register_op("op_ws_next_event", s.stateful_json_op2(op_ws_next_event));
+}
+
+type MaybeTlsStream =
+  StreamSwitcher<TcpStream, tokio_rustls::client::TlsStream<TcpStream>>;
+
+type WsStream = WebSocketStream<MaybeTlsStream>;
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct CreateArgs {
+  url: String,
+  protocols: String,
+}
+
+pub fn op_ws_create(
+  isolate_state: &mut CoreIsolateState,
+  state: &Rc<State>,
+  args: Value,
+  _zero_copy: &mut [ZeroCopyBuf],
+) -> Result<JsonOp, ErrBox> {
+  let args: CreateArgs = serde_json::from_value(args)?;
+  state.check_net_url(&url::Url::parse(&args.url)?)?;
+  let resource_table = isolate_state.resource_table.clone();
+  let ca_file = state.global_state.flags.ca_file.clone();
+  let future = async move {
+    let uri: Uri = args.url.parse().unwrap();
+    let request = Request::builder()
+      .method(Method::GET)
+      .uri(&uri)
+      .header("Sec-WebSocket-Protocol", args.protocols)
+      .body(())
+      .unwrap();
+    let domain = &uri.host().unwrap().to_string();
+    let port = &uri.port_u16().unwrap_or(match uri.scheme_str() {
+      Some("wss") => 443,
+      Some("ws") => 80,
+      _ => unreachable!(),
+    });
+    let addr = format!("{}:{}", domain, port);
+    let try_socket = TcpStream::connect(addr).await;
+    let tcp_socket = match try_socket.map_err(Error::Io) {
+      Ok(socket) => socket,
+      Err(_) => return Ok(json!({"success": false})),
+    };
+
+    let socket: MaybeTlsStream = match uri.scheme_str() {
+      Some("ws") => StreamSwitcher::Plain(tcp_socket),
+      Some("wss") => {
+        let mut config = ClientConfig::new();
+        config
+          .root_store
+          .add_server_trust_anchors(&webpki_roots::TLS_SERVER_ROOTS);
+
+        if let Some(path) = ca_file {
+          let key_file = File::open(path)?;
+          let reader = &mut BufReader::new(key_file);
+          config.root_store.add_pem_file(reader).unwrap();
+        }
+
+        let tls_connector = TlsConnector::from(Arc::new(config));
+        let dnsname =
+          DNSNameRef::try_from_ascii_str(&domain).expect("Invalid DNS lookup");
+        let tls_socket = tls_connector.connect(dnsname, tcp_socket).await?;
+        StreamSwitcher::Tls(tls_socket)
+      }
+      _ => unreachable!(),
+    };
+
+    let (stream, response): (WsStream, Response) =
+      client_async(request, socket).await.unwrap();
+
+    let rid = {
+      let mut resource_table = resource_table.borrow_mut();
+      resource_table.add("webSocketStream", Box::new(stream))
+    };
+
+    let protocol = match response.headers().get("Sec-WebSocket-Protocol") {
+      Some(header) => header.to_str().unwrap(),
+      None => "",
+    };
+    let extensions = response
+      .headers()
+      .get_all("Sec-WebSocket-Extensions")
+      .iter()
+      .map(|header| header.to_str().unwrap())
+      .collect::<String>();
+    Ok(json!({
+    "success": true,
+    "rid": rid,
+    "protocol": protocol,
+    "extensions": extensions
+    }))
+  };
+  Ok(JsonOp::Async(future.boxed_local()))
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct SendArgs {
+  rid: u32,
+  text: Option<String>,
+}
+
+pub fn op_ws_send(
+  isolate_state: &mut CoreIsolateState,
+  _state: &Rc<State>,
+  args: Value,
+  zero_copy: &mut [ZeroCopyBuf],
+) -> Result<JsonOp, ErrBox> {
+  let args: SendArgs = serde_json::from_value(args)?;
+
+  let mut maybe_msg = Some(match args.text {
+    Some(text) => Message::Text(text),
+    None => Message::Binary(zero_copy[0].to_owned().to_vec()),
+  });
+  let resource_table = isolate_state.resource_table.clone();
+  let rid = args.rid;
+
+  let future = poll_fn(move |cx| {
+    let mut resource_table = resource_table.borrow_mut();
+    let stream = resource_table
+      .get_mut::<WsStream>(rid)
+      .ok_or_else(ErrBox::bad_resource_id)?;
+
+    // TODO(ry) Handle errors below instead of unwrap.
+    // Need to map tungstenite::error::Error to ErrBox.
+
+    ready!(stream.poll_ready_unpin(cx)).unwrap();
+    if let Some(msg) = maybe_msg.take() {
+      stream.start_send_unpin(msg).unwrap();
+    }
+    ready!(stream.poll_flush_unpin(cx)).unwrap();
+
+    Poll::Ready(Ok(json!({})))
+  });
+  Ok(JsonOp::Async(future.boxed_local()))
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct CloseArgs {
+  rid: u32,
+  code: Option<u16>,
+  reason: Option<String>,
+}
+
+pub fn op_ws_close(
+  isolate_state: &mut CoreIsolateState,
+  _state: &Rc<State>,
+  args: Value,
+  _zero_copy: &mut [ZeroCopyBuf],
+) -> Result<JsonOp, ErrBox> {
+  let args: CloseArgs = serde_json::from_value(args)?;
+  let resource_table = isolate_state.resource_table.clone();
+  let rid = args.rid;
+  let mut maybe_msg = Some(Message::Close(args.code.map(|c| CloseFrame {
+    code: CloseCode::from(c),
+    reason: match args.reason {
+      Some(reason) => Cow::from(reason),
+      None => Default::default(),
+    },
+  })));
+
+  let future = poll_fn(move |cx| {
+    let mut resource_table = resource_table.borrow_mut();
+    let stream = resource_table
+      .get_mut::<WsStream>(rid)
+      .ok_or_else(ErrBox::bad_resource_id)?;
+
+    // TODO(ry) Handle errors below instead of unwrap.
+    // Need to map tungstenite::error::Error to ErrBox.
+
+    ready!(stream.poll_ready_unpin(cx)).unwrap();
+    if let Some(msg) = maybe_msg.take() {
+      stream.start_send_unpin(msg).unwrap();
+    }
+    ready!(stream.poll_flush_unpin(cx)).unwrap();
+    ready!(stream.poll_close_unpin(cx)).unwrap();
+
+    Poll::Ready(Ok(json!({})))
+  });
+
+  Ok(JsonOp::Async(future.boxed_local()))
+}
+
+#[derive(Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct NextEventArgs {
+  rid: u32,
+}
+
+pub fn op_ws_next_event(
+  isolate_state: &mut CoreIsolateState,
+  _state: &Rc<State>,
+  args: Value,
+  _zero_copy: &mut [ZeroCopyBuf],
+) -> Result<JsonOp, ErrBox> {
+  let args: NextEventArgs = serde_json::from_value(args)?;
+  let resource_table = isolate_state.resource_table.clone();
+  let future = poll_fn(move |cx| {
+    let mut resource_table = resource_table.borrow_mut();
+    let stream = resource_table
+      .get_mut::<WsStream>(args.rid)
+      .ok_or_else(ErrBox::bad_resource_id)?;
+
+    stream.poll_next_unpin(cx).map(|val| {
+      match val {
+        Some(val) => {
+          match val {
+            Ok(message) => {
+              match message {
+                Message::Text(text) => Ok(json!({
+                  "type": "string",
+                  "data": text
+                })),
+                Message::Binary(data) => {
+                  Ok(json!({ //TODO: don't use json to send binary data
+                    "type": "binary",
+                    "data": data
+                  }))
+                }
+                Message::Close(frame) => {
+                  if let Some(frame) = frame {
+                    let code: u16 = frame.code.into();
+                    Ok(json!({
+                      "type": "close",
+                      "code": code,
+                      "reason": frame.reason.as_ref()
+                    }))
+                  } else {
+                    Ok(json!({ "type": "close" }))
+                  }
+                }
+                Message::Ping(_) => Ok(json!({"type": "ping"})),
+                Message::Pong(_) => Ok(json!({"type": "pong"})),
+              }
+            }
+            Err(_) => Ok(json!({
+              "type": "error",
+            })),
+          }
+        }
+        None => {
+          resource_table
+            .close(args.rid)
+            .ok_or_else(ErrBox::bad_resource_id)?;
+          Ok(json!({
+            "type": "closed",
+          }))
+        }
+      }
+    })
+  });
+
+  Ok(JsonOp::Async(future.boxed_local()))
+}
diff --git a/cli/rt/11_workers.js b/cli/rt/11_workers.js
index 8ae0d5ad5..9a23e3dd8 100644
--- a/cli/rt/11_workers.js
+++ b/cli/rt/11_workers.js
@@ -39,20 +39,6 @@
   const encoder = new TextEncoder();
   const decoder = new TextDecoder();
 
-  class MessageEvent extends Event {
-    constructor(type, eventInitDict) {
-      super(type, {
-        bubbles: eventInitDict?.bubbles ?? false,
-        cancelable: eventInitDict?.cancelable ?? false,
-        composed: eventInitDict?.composed ?? false,
-      });
-
-      this.data = eventInitDict?.data ?? null;
-      this.origin = eventInitDict?.origin ?? "";
-      this.lastEventId = eventInitDict?.lastEventId ?? "";
-    }
-  }
-
   function encodeMessage(data) {
     const dataJson = JSON.stringify(data);
     return encoder.encode(dataJson);
@@ -226,6 +212,5 @@
 
   window.__bootstrap.worker = {
     Worker,
-    MessageEvent,
   };
 })(this);
diff --git a/cli/rt/27_websocket.js b/cli/rt/27_websocket.js
new file mode 100644
index 000000000..0b113ebca
--- /dev/null
+++ b/cli/rt/27_websocket.js
@@ -0,0 +1,305 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+((window) => {
+  const { sendAsync } = window.__bootstrap.dispatchJson;
+  const { close } = window.__bootstrap.resources;
+  const { requiredArguments } = window.__bootstrap.webUtil;
+  const CONNECTING = 0;
+  const OPEN = 1;
+  const CLOSING = 2;
+  const CLOSED = 3;
+
+  class WebSocket extends EventTarget {
+    #readyState = CONNECTING;
+
+    constructor(url, protocols = []) {
+      super();
+      requiredArguments("WebSocket", arguments.length, 1);
+
+      const wsURL = new URL(url);
+
+      if (wsURL.protocol !== "ws:" && wsURL.protocol !== "wss:") {
+        throw new DOMException(
+          "Only ws & wss schemes are allowed in a WebSocket URL.",
+          "SyntaxError",
+        );
+      }
+
+      if (wsURL.hash !== "" || wsURL.href.endsWith("#")) {
+        throw new DOMException(
+          "Fragments are not allowed in a WebSocket URL.",
+          "SyntaxError",
+        );
+      }
+
+      this.#url = wsURL.href;
+
+      if (protocols && typeof protocols === "string") {
+        protocols = [protocols];
+      }
+
+      if (
+        protocols.some((x) => protocols.indexOf(x) !== protocols.lastIndexOf(x))
+      ) {
+        throw new DOMException(
+          "Can't supply multiple times the same protocol.",
+          "SyntaxError",
+        );
+      }
+
+      sendAsync("op_ws_create", {
+        url: wsURL.href,
+        protocols: protocols.join("; "),
+      }).then((create) => {
+        if (create.success) {
+          this.#rid = create.rid;
+          this.#extensions = create.extensions;
+          this.#protocol = create.protocol;
+
+          if (this.#readyState === CLOSING) {
+            sendAsync("op_ws_close", {
+              rid: this.#rid,
+            }).then(() => {
+              this.#readyState = CLOSED;
+
+              const errEvent = new Event("error");
+              errEvent.target = this;
+              this.onerror?.(errEvent);
+              this.dispatchEvent(errEvent);
+
+              const event = new CloseEvent("close");
+              event.target = this;
+              this.onclose?.(event);
+              this.dispatchEvent(event);
+              close(this.#rid);
+            });
+
+            const event = new Event("error");
+            event.target = this;
+            this.onerror?.(event);
+            this.dispatchEvent(event);
+          } else {
+            this.#readyState = OPEN;
+            const event = new Event("open");
+            event.target = this;
+            this.onopen?.(event);
+            this.dispatchEvent(event);
+
+            this.#eventLoop();
+          }
+        } else {
+          this.#readyState = CLOSED;
+
+          const errEvent = new Event("error");
+          errEvent.target = this;
+          this.onerror?.(errEvent);
+          this.dispatchEvent(errEvent);
+
+          const closeEvent = new CloseEvent("close");
+          closeEvent.target = this;
+          this.onclose?.(closeEvent);
+          this.dispatchEvent(closeEvent);
+        }
+      });
+    }
+
+    get CONNECTING() {
+      return CONNECTING;
+    }
+    get OPEN() {
+      return OPEN;
+    }
+    get CLOSING() {
+      return CLOSING;
+    }
+    get CLOSED() {
+      return CLOSED;
+    }
+
+    get readyState() {
+      return this.#readyState;
+    }
+
+    #extensions = "";
+    #protocol = "";
+    #url = "";
+    #rid;
+
+    get extensions() {
+      return this.#extensions;
+    }
+    get protocol() {
+      return this.#protocol;
+    }
+
+    #binaryType = "blob";
+    get binaryType() {
+      return this.#binaryType;
+    }
+    set binaryType(value) {
+      if (value === "blob" || value === "arraybuffer") {
+        this.#binaryType = value;
+      }
+    }
+    #bufferedAmount = 0;
+    get bufferedAmount() {
+      return this.#bufferedAmount;
+    }
+
+    get url() {
+      return this.#url;
+    }
+
+    onopen = () => {};
+    onerror = () => {};
+    onclose = () => {};
+    onmessage = () => {};
+
+    send(data) {
+      requiredArguments("WebSocket.send", arguments.length, 1);
+
+      if (this.#readyState != OPEN) {
+        throw Error("readyState not OPEN");
+      }
+
+      const sendTypedArray = (ta) => {
+        this.#bufferedAmount += ta.size;
+        sendAsync("op_ws_send", {
+          rid: this.#rid,
+        }, ta).then(() => {
+          this.#bufferedAmount -= ta.size;
+        });
+      };
+
+      if (data instanceof Blob) {
+        data.slice().arrayBuffer().then((ab) =>
+          sendTypedArray(new DataView(ab))
+        );
+      } else if (
+        data instanceof Int8Array || data instanceof Int16Array ||
+        data instanceof Int32Array || data instanceof Uint8Array ||
+        data instanceof Uint16Array || data instanceof Uint32Array ||
+        data instanceof Uint8ClampedArray || data instanceof Float32Array ||
+        data instanceof Float64Array || data instanceof DataView
+      ) {
+        sendTypedArray(data);
+      } else if (data instanceof ArrayBuffer) {
+        sendTypedArray(new DataView(data));
+      } else {
+        const string = String(data);
+        const encoder = new TextEncoder();
+        const d = encoder.encode(string);
+        this.#bufferedAmount += d.size;
+        sendAsync("op_ws_send", {
+          rid: this.#rid,
+          text: string,
+        }).then(() => {
+          this.#bufferedAmount -= d.size;
+        });
+      }
+    }
+
+    close(code, reason) {
+      if (code && (code !== 1000 && !(3000 <= code > 5000))) {
+        throw new DOMException(
+          "The close code must be either 1000 or in the range of 3000 to 4999.",
+          "NotSupportedError",
+        );
+      }
+
+      const encoder = new TextEncoder();
+      if (reason && encoder.encode(reason).byteLength > 123) {
+        throw new DOMException(
+          "The close reason may not be longer than 123 bytes.",
+          "SyntaxError",
+        );
+      }
+
+      if (this.#readyState === CONNECTING) {
+        this.#readyState = CLOSING;
+      } else if (this.#readyState === OPEN) {
+        this.#readyState = CLOSING;
+
+        sendAsync("op_ws_close", {
+          rid: this.#rid,
+          code,
+          reason,
+        }).then(() => {
+          this.#readyState = CLOSED;
+          const event = new CloseEvent("close", {
+            wasClean: true,
+            code,
+            reason,
+          });
+          event.target = this;
+          this.onclose?.(event);
+          this.dispatchEvent(event);
+          close(this.#rid);
+        });
+      }
+    }
+
+    async #eventLoop() {
+      if (this.#readyState === OPEN) {
+        const message = await sendAsync("op_ws_next_event", { rid: this.#rid });
+        if (message.type === "string" || message.type === "binary") {
+          let data;
+
+          if (message.type === "string") {
+            data = message.data;
+          } else {
+            if (this.binaryType === "blob") {
+              data = new Blob([new Uint8Array(message.data)]);
+            } else {
+              data = new Uint8Array(message.data).buffer;
+            }
+          }
+
+          const event = new MessageEvent("message", {
+            data,
+            origin: this.#url,
+          });
+          event.target = this;
+          this.onmessage?.(event);
+          this.dispatchEvent(event);
+
+          this.#eventLoop();
+        } else if (message.type === "close") {
+          this.#readyState = CLOSED;
+          const event = new CloseEvent("close", {
+            wasClean: true,
+            code: message.code,
+            reason: message.reason,
+          });
+          event.target = this;
+          this.onclose?.(event);
+          this.dispatchEvent(event);
+        } else if (message.type === "error") {
+          const event = new Event("error");
+          event.target = this;
+          this.onerror?.(event);
+          this.dispatchEvent(event);
+        }
+      }
+    }
+  }
+
+  Object.defineProperties(WebSocket, {
+    CONNECTING: {
+      value: 0,
+    },
+    OPEN: {
+      value: 1,
+    },
+    CLOSING: {
+      value: 2,
+    },
+    CLOSED: {
+      value: 3,
+    },
+  });
+
+  window.__bootstrap.webSocket = {
+    WebSocket,
+  };
+})(this);
diff --git a/cli/rt/99_main.js b/cli/rt/99_main.js
index c6d6d1395..ede47980c 100644
--- a/cli/rt/99_main.js
+++ b/cli/rt/99_main.js
@@ -30,6 +30,7 @@ delete Object.prototype.__proto__;
   const progressEvent = window.__bootstrap.progressEvent;
   const fileReader = window.__bootstrap.fileReader;
   const formData = window.__bootstrap.formData;
+  const webSocket = window.__bootstrap.webSocket;
   const request = window.__bootstrap.request;
   const fetch = window.__bootstrap.fetch;
   const denoNs = window.__bootstrap.denoNs;
@@ -80,7 +81,7 @@ delete Object.prototype.__proto__;
 
   let isClosing = false;
   async function workerMessageRecvCallback(data) {
-    const msgEvent = new worker.MessageEvent("message", {
+    const msgEvent = new MessageEvent("message", {
       cancelable: false,
       data,
     });
@@ -232,10 +233,13 @@ delete Object.prototype.__proto__;
     CustomEvent: util.nonEnumerable(CustomEvent),
     DOMException: util.nonEnumerable(DOMException),
     ErrorEvent: util.nonEnumerable(ErrorEvent),
+    CloseEvent: util.nonEnumerable(CloseEvent),
+    MessageEvent: util.nonEnumerable(MessageEvent),
     Event: util.nonEnumerable(Event),
     EventTarget: util.nonEnumerable(EventTarget),
     Headers: util.nonEnumerable(headers.Headers),
     FormData: util.nonEnumerable(formData.FormData),
+    WebSocket: util.nonEnumerable(webSocket.WebSocket),
     ReadableStream: util.nonEnumerable(streams.ReadableStream),
     Request: util.nonEnumerable(request.Request),
     Response: util.nonEnumerable(fetch.Response),
diff --git a/cli/tests/integration_tests.rs b/cli/tests/integration_tests.rs
index 08c68a9ae..94d410dcc 100644
--- a/cli/tests/integration_tests.rs
+++ b/cli/tests/integration_tests.rs
@@ -3205,6 +3205,27 @@ async fn inspector_runtime_evaluate_does_not_crash() {
 }
 
 #[test]
+fn websocket() {
+  let _g = util::http_server();
+
+  let script = util::tests_path().join("websocket_test.ts");
+  let root_ca = util::tests_path().join("tls/RootCA.pem");
+  let status = util::deno_cmd()
+    .arg("test")
+    .arg("--unstable")
+    .arg("--allow-net")
+    .arg("--cert")
+    .arg(root_ca)
+    .arg(script)
+    .spawn()
+    .unwrap()
+    .wait()
+    .unwrap();
+
+  assert!(status.success());
+}
+
+#[test]
 fn exec_path() {
   let output = util::deno_cmd()
     .current_dir(util::root_path())
diff --git a/cli/tests/websocket_test.ts b/cli/tests/websocket_test.ts
new file mode 100644
index 000000000..0fb9af951
--- /dev/null
+++ b/cli/tests/websocket_test.ts
@@ -0,0 +1,259 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import {
+  assertEquals,
+  assertThrows,
+  createResolvable,
+  fail,
+} from "./unit/test_util.ts";
+
+Deno.test("invalid scheme", () => {
+  assertThrows(() => new WebSocket("foo://localhost:4242"));
+});
+
+Deno.test("fragment", () => {
+  assertThrows(() => new WebSocket("ws://localhost:4242/#"));
+  assertThrows(() => new WebSocket("ws://localhost:4242/#foo"));
+});
+
+Deno.test("duplicate protocols", () => {
+  assertThrows(() => new WebSocket("ws://localhost:4242", ["foo", "foo"]));
+});
+
+Deno.test("invalid server", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:2121");
+  let err = false;
+  ws.onerror = (): void => {
+    err = true;
+  };
+  ws.onclose = (): void => {
+    if (err) {
+      promise.resolve();
+    } else {
+      fail();
+    }
+  };
+  ws.onopen = (): void => fail();
+  await promise;
+});
+
+Deno.test("connect & close", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => {
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("connect & abort", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  ws.close();
+  let err = false;
+  ws.onerror = (): void => {
+    err = true;
+  };
+  ws.onclose = (): void => {
+    if (err) {
+      promise.resolve();
+    } else {
+      fail();
+    }
+  };
+  ws.onopen = (): void => fail();
+  await promise;
+});
+
+Deno.test("connect & close custom valid code", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => ws.close(1000);
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("connect & close custom invalid code", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => {
+    assertThrows(() => ws.close(1001));
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("connect & close custom valid reason", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => ws.close(1000, "foo");
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("connect & close custom invalid reason", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => {
+    assertThrows(() => ws.close(1000, "".padEnd(124, "o")));
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("echo string", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => ws.send("foo");
+  ws.onmessage = (e): void => {
+    assertEquals(e.data, "foo");
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("echo string tls", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("wss://localhost:4243");
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => ws.send("foo");
+  ws.onmessage = (e): void => {
+    assertEquals(e.data, "foo");
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("echo blob with binaryType blob", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  const blob = new Blob(["foo"]);
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => ws.send(blob);
+  ws.onmessage = (e): void => {
+    e.data.text().then((actual: string) => {
+      blob.text().then((expected) => {
+        assertEquals(actual, expected);
+      });
+    });
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("echo blob with binaryType arraybuffer", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  ws.binaryType = "arraybuffer";
+  const blob = new Blob(["foo"]);
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => ws.send(blob);
+  ws.onmessage = (e): void => {
+    blob.arrayBuffer().then((expected) => {
+      assertEquals(e.data, expected);
+    });
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("echo uint8array with binaryType blob", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  const uint = new Uint8Array([102, 111, 111]);
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => ws.send(uint);
+  ws.onmessage = (e): void => {
+    e.data.arrayBuffer().then((actual: ArrayBuffer) => {
+      assertEquals(actual, uint.buffer);
+    });
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("echo uint8array with binaryType arraybuffer", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  ws.binaryType = "arraybuffer";
+  const uint = new Uint8Array([102, 111, 111]);
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => ws.send(uint);
+  ws.onmessage = (e): void => {
+    assertEquals(e.data, uint.buffer);
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("echo arraybuffer with binaryType blob", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  const buffer = new ArrayBuffer(3);
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => ws.send(buffer);
+  ws.onmessage = (e): void => {
+    e.data.arrayBuffer().then((actual: ArrayBuffer) => {
+      assertEquals(actual, buffer);
+    });
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
+
+Deno.test("echo arraybuffer with binaryType arraybuffer", async () => {
+  const promise = createResolvable();
+  const ws = new WebSocket("ws://localhost:4242");
+  ws.binaryType = "arraybuffer";
+  const buffer = new ArrayBuffer(3);
+  ws.onerror = (): void => fail();
+  ws.onopen = (): void => ws.send(buffer);
+  ws.onmessage = (e): void => {
+    assertEquals(e.data, buffer);
+    ws.close();
+  };
+  ws.onclose = (): void => {
+    promise.resolve();
+  };
+  await promise;
+});
diff --git a/cli/web_worker.rs b/cli/web_worker.rs
index 8d9c00499..9b42ebe32 100644
--- a/cli/web_worker.rs
+++ b/cli/web_worker.rs
@@ -127,6 +127,7 @@ impl WebWorker {
       ops::errors::init(isolate, &state);
       ops::timers::init(isolate, &state);
       ops::fetch::init(isolate, &state);
+      ops::websocket::init(isolate, &state);
 
       if has_deno_namespace {
         ops::runtime_compiler::init(isolate, &state);
diff --git a/cli/worker.rs b/cli/worker.rs
index 0129242e6..3773871dc 100644
--- a/cli/worker.rs
+++ b/cli/worker.rs
@@ -263,6 +263,7 @@ impl MainWorker {
       ops::runtime_compiler::init(isolate, &state);
       ops::errors::init(isolate, &state);
       ops::fetch::init(isolate, &state);
+      ops::websocket::init(isolate, &state);
       ops::fs::init(isolate, &state);
       ops::fs_events::init(isolate, &state);
       ops::idna::init(isolate, &state);
diff --git a/op_crates/web/01_event.js b/op_crates/web/01_event.js
index 48899e6fd..5b21d4402 100644
--- a/op_crates/web/01_event.js
+++ b/op_crates/web/01_event.js
@@ -1011,6 +1011,55 @@
     "error",
   ]);
 
+  class CloseEvent extends Event {
+    #wasClean = "";
+    #code = "";
+    #reason = "";
+
+    get wasClean() {
+      return this.#wasClean;
+    }
+    get code() {
+      return this.#code;
+    }
+    get reason() {
+      return this.#reason;
+    }
+
+    constructor(type, {
+      bubbles,
+      cancelable,
+      composed,
+      wasClean = false,
+      code = 0,
+      reason = "",
+    } = {}) {
+      super(type, {
+        bubbles: bubbles,
+        cancelable: cancelable,
+        composed: composed,
+      });
+
+      this.#wasClean = wasClean;
+      this.#code = code;
+      this.#reason = reason;
+    }
+  }
+
+  class MessageEvent extends Event {
+    constructor(type, eventInitDict) {
+      super(type, {
+        bubbles: eventInitDict?.bubbles ?? false,
+        cancelable: eventInitDict?.cancelable ?? false,
+        composed: eventInitDict?.composed ?? false,
+      });
+
+      this.data = eventInitDict?.data ?? null;
+      this.origin = eventInitDict?.origin ?? "";
+      this.lastEventId = eventInitDict?.lastEventId ?? "";
+    }
+  }
+
   class CustomEvent extends Event {
     #detail = null;
 
@@ -1037,6 +1086,8 @@
   window.Event = Event;
   window.EventTarget = EventTarget;
   window.ErrorEvent = ErrorEvent;
+  window.CloseEvent = CloseEvent;
+  window.MessageEvent = MessageEvent;
   window.CustomEvent = CustomEvent;
   window.dispatchEvent = EventTarget.prototype.dispatchEvent;
   window.addEventListener = EventTarget.prototype.addEventListener;
diff --git a/test_util/src/lib.rs b/test_util/src/lib.rs
index 1f8548e34..832c40f59 100644
--- a/test_util/src/lib.rs
+++ b/test_util/src/lib.rs
@@ -39,6 +39,8 @@ const DOUBLE_REDIRECTS_PORT: u16 = 4548;
 const INF_REDIRECTS_PORT: u16 = 4549;
 const REDIRECT_ABSOLUTE_PORT: u16 = 4550;
 const HTTPS_PORT: u16 = 5545;
+const WS_PORT: u16 = 4242;
+const WSS_PORT: u16 = 4243;
 
 pub const PERMISSION_VARIANTS: [&str; 5] =
   ["read", "write", "env", "net", "run"];
@@ -135,6 +137,25 @@ pub async fn run_all_servers() {
   let redirect_server_fut =
     warp::serve(routes).bind(([127, 0, 0, 1], REDIRECT_PORT));
 
+  let websocket_route = warp::ws().map(|ws: warp::ws::Ws| {
+    ws.on_upgrade(|websocket| {
+      use futures::stream::StreamExt;
+      let (tx, rx) = websocket.split();
+      rx.forward(tx).map(|result| {
+        if let Err(e) = result {
+          println!("websocket server error: {:?}", e);
+        }
+      })
+    })
+  });
+  let ws_server_fut =
+    warp::serve(websocket_route).bind(([127, 0, 0, 1], WS_PORT));
+  let wss_server_fut = warp::serve(websocket_route)
+    .tls()
+    .cert_path("std/http/testdata/tls/localhost.crt")
+    .key_path("std/http/testdata/tls/localhost.key")
+    .bind(([127, 0, 0, 1], WSS_PORT));
+
   let routes = warp::path::full().map(|path: warp::path::FullPath| {
     let p = path.as_str();
     assert_eq!(&p[0..1], "/");
@@ -426,6 +447,8 @@ pub async fn run_all_servers() {
       http_fut,
       https_fut,
       redirect_server_fut,
+      ws_server_fut,
+      wss_server_fut,
       another_redirect_server_fut,
       inf_redirect_server_fut,
       double_redirect_server_fut,