Replace socket.io with plain WebSocket

Replace socket.io with plain WebSocket using the ws library as it
doesn't really provide any useful tools over plain WebSocket when it
comes to implementing reliable communication that works across
reconnects.  The widespread browser support for WebSocket also means
it has little value to add for the web interface over WebSocket.

test/lib/link/connector.js

@@ -6,14 +6,14 @@ const link = require('lib/link');
 
 
 describe("lib/link/connectors", function() {
-	describe("class SocketIOClientConnector", function() {
-		let testConnector = new link.SocketIOClientConnector('source', 'url', 'token');
+	describe("class WebSocketClientConnector", function() {
+		let testConnector = new link.WebSocketClientConnector('source', 'url');
 		testConnector._socket = new mock.MockSocket();
 		describe(".disconnect()", function() {
-			it("should call close on the socket", function() {
-				testConnector._socket.closeCalled = false;
+			it("should call terminate on the socket", function() {
+				testConnector._socket.terminateCalled = false;
 				testConnector.disconnect();
-				assert(testConnector._socket.closeCalled, "Close was not called");
+				assert(testConnector._socket.terminateCalled, "Close was not called");
 			});
 		});
 
@@ -30,21 +30,22 @@ describe("lib/link/connectors", function() {
 			it("calls send on the socket", function() {
 				testConnector._socket.sentMessages = [];
 				let seq = testConnector.send('test', { test: true });
-				assert.deepEqual(testConnector._socket.sentMessages, [{ seq, type: 'test', data: { test: true }}]);
+				assert.deepEqual(
+					testConnector._socket.sentMessages.map(JSON.parse),
+					[{ seq, type: 'test', data: { test: true }}]
+				);
 			});
 		});
 
 		describe(".close()", function() {
-			it("should send close and call disconnect", function() {
+			it("should send close", function() {
 				testConnector._socket.sentMessages = [];
 				let called = false;
-				testConnector.disconnect = () => { called = true; }
 				testConnector.close("test reason");
 				assert.deepEqual(
-					testConnector._socket.sentMessages,
+					testConnector._socket.sentMessages.map(JSON.parse),
 					[{ seq: testConnector._seq - 1, type: 'close', data: { reason: "test reason" } }]
 				)
-				assert(called, ".disconnect() was not called");
 			});
 		});
 
@@ -53,7 +54,7 @@ describe("lib/link/connectors", function() {
 				testConnector._socket.sentMessages = [];
 				testConnector._processHandshake({ data: "invalid message" }),
 				assert.deepEqual(
-					testConnector._socket.sentMessages,
+					testConnector._socket.sentMessages.map(JSON.parse),
 					[{seq: testConnector._seq - 1, type: 'close', data: {
 						reason: "Invalid handshake" }
 					}]
@@ -85,7 +86,7 @@ describe("lib/link/connectors", function() {
 			it("should throw on message received in invalid state", function() {
 				testConnector._state = "new";
 				assert.throws(
-					() => testConnector._socket.events.get('message')(),
+					() => testConnector._socket.events.get("message")("{}"),
 					new Error("Received message in unexpected state new")
 				);
 			});
@@ -93,15 +94,15 @@ describe("lib/link/connectors", function() {
 				testConnector._state = "handshake";
 				let called = false;
 				testConnector._processHandshake = () => { called = true; };
-				testConnector._socket.events.get('message')();
+				testConnector._socket.events.get("message")("{}");
 				assert(called, "_processHandshake was not called");
 			});
 			it("should emit message on message in ready state", async function() {
 				testConnector._socket.sentMessages = [];
 				testConnector._state = "ready";
 				let result = events.once(testConnector, 'message');
-				testConnector._socket.events.get('message')("message");
-				assert.deepEqual(await result, ["message"]);
+				testConnector._socket.events.get("message")('{"message":true}');
+				assert.deepEqual(await result, [{ message: true }]);
 			});
 		});
 	});

test/master.js

@@ -63,13 +63,13 @@ describe('Master testing', function() {
 		}
 	});
 
-	describe("class SocketIOServerConnector", function() {
-		let testConnector = new master._SocketIOServerConnector(new mock.MockSocket());
+	describe("class WebSocketServerConnector", function() {
+		let testConnector = new master._WebSocketServerConnector(new mock.MockSocket());
 		describe(".disconnect()", function() {
 			it("should call disconnect on the socket", function() {
-				testConnector._socket.disconnectCalled = false;
+				testConnector._socket.terminateCalled = false;
 				testConnector.disconnect();
-				assert(testConnector._socket.disconnectCalled, "Disconnect was not called");
+				assert(testConnector._socket.terminateCalled, "Terminate was not called");
 			});
 		});
 	});

test/mock.js

@@ -7,7 +7,6 @@ class MockSocket {
 	constructor() {
 		this.sentMessages = [];
 		this.events = new Map();
-		this.handshake = { address: "socket.test" };
 	}
 
 	send(message) {
@@ -18,8 +17,8 @@ class MockSocket {
 		this.events.set(event, fn);
 	}
 
-	disconnect() {
-		this.disconnectCalled = true;
+	terminate() {
+		this.terminateCalled = true;
 	}
 
 	close() {