adding codec and encoding tests

packages/teleport/src/lib/tdp/codec.test.ts

@@ -0,0 +1,108 @@
+const { TextEncoder } = require('util');
+import Codec, { MessageType, ButtonState, MouseButton } from './codec';
+
+// Use nodejs TextEncoder until jsdom adds support for TextEncoder (https://github.com/jsdom/jsdom/issues/2524)
+window.TextEncoder = window.TextEncoder || TextEncoder;
+const codec = new Codec();
+
+test('encodes the screen spec', () => {
+  const w = 1800;
+  const h = 1200;
+  const message = codec.encodeScreenSpec(w, h);
+  const view = new DataView(message);
+  expect(view.getUint8(0)).toEqual(MessageType.CLIENT_SCREEN_SPEC);
+  expect(view.getUint32(1)).toEqual(w);
+  expect(view.getUint32(5)).toEqual(h);
+});
+
+test('encodes mouse moves', () => {
+  const x = 0;
+  const y = Math.pow(2, 32) - 1;
+  const message = codec.encodeMouseMove(x, y);
+  const view = new DataView(message);
+  expect(view.getUint8(0)).toEqual(MessageType.MOUSE_MOVE);
+  expect(view.getUint32(1)).toEqual(x);
+  expect(view.getUint32(5)).toEqual(y);
+});
+
+test('encodes mouse buttons', () => {
+  [0, 1, 2].forEach(button => {
+    [ButtonState.DOWN, ButtonState.UP].forEach(state => {
+      const message = codec.encodeMouseButton(button as MouseButton, state);
+      const view = new DataView(message);
+      expect(view.getUint8(0)).toEqual(MessageType.MOUSE_BUTTON);
+      expect(view.getUint8(1)).toEqual(button);
+      expect(view.getUint8(2)).toEqual(state);
+    });
+  });
+});
+
+// Username/password tests inspired by https://github.com/google/closure-library/blob/master/closure/goog/crypt/crypt_test.js (Apache License)
+test('encodes typical characters for username and password', () => {
+  // Create a test value with letters, symbols, and numbers and its known UTF8 encodings
+  const username = 'Helloworld!*@123';
+  const usernameUTF8 = [
+    0x0048,
+    0x0065,
+    0x006c,
+    0x006c,
+    0x006f,
+    0x0077,
+    0x006f,
+    0x0072,
+    0x006c,
+    0x0064,
+    0x0021,
+    0x002a,
+    0x0040,
+    0x0031,
+    0x0032,
+    0x0033,
+  ];
+
+  // Encode test vals
+  const message = codec.encodeUsername(username);
+  const view = new DataView(message);
+
+  // Walk through output
+  let offset = 0;
+  expect(view.getUint8(offset++)).toEqual(MessageType.CLIENT_USERNAME);
+  expect(view.getUint32(offset)).toEqual(usernameUTF8.length);
+  offset += 4;
+  usernameUTF8.forEach(byte => {
+    expect(view.getUint8(offset++)).toEqual(byte);
+  });
+});
+
+test('encodes utf8 characters correctly up to 3 bytes for username and password', () => {
+  const first3RangesString = '\u0000\u007F\u0080\u07FF\u0800\uFFFF';
+  const first3RangesUTF8 = [
+    0x00,
+    0x7f,
+    0xc2,
+    0x80,
+    0xdf,
+    0xbf,
+    0xe0,
+    0xa0,
+    0x80,
+    0xef,
+    0xbf,
+    0xbf,
+  ];
+  const message = codec.encodeUsername(first3RangesString);
+  const view = new DataView(message);
+  let offset = 0;
+  expect(view.getUint8(offset++)).toEqual(MessageType.CLIENT_USERNAME);
+  expect(view.getUint32(offset)).toEqual(first3RangesUTF8.length);
+  offset += 4;
+  first3RangesUTF8.forEach(byte => {
+    expect(view.getUint8(offset++)).toEqual(byte);
+  });
+});
+
+// todo until jsdom adds support for Blob.arrayBuffer() (https://github.com/jsdom/jsdom/issues/2555)
+test.todo(`TODO: decoding -- jest uses jsdom to emulate a browser environment during the tests, but jsdom does not currently
+    support Blob.arrayBuffer() (used in our decoding functions) and thus it is difficult to test.
+    I think I've come up with a hacky workaround but @awly and I agreed to put this aside
+    for the time being; all will be tested manually for now by necessity during development.`);