Fix connection close by server treatment by WebSocket channels (#684)

The lack of set channel._open to false when the onclose event is triggered was causing the channel be broken without the other parts of the driver notice. In tbis way, a next iteration trying to get the broken connection will succeded in the try and run the query will result in a eternal pending promise.

Mark the channel as closed enable the pool to discard and create a new connection if it needed.

Author: bigmontz

src/v1/internal/browser/browser-channel.js

@@ -31,7 +31,11 @@ export default class WebSocketChannel {
    * @param {ChannelConfig} config - configuration for this channel.
    * @param {function(): string} protocolSupplier - function that detects protocol of the web page. Should only be used in tests.
    */
-  constructor (config, protocolSupplier = detectWebPageProtocol) {
+  constructor (
+    config,
+    protocolSupplier = detectWebPageProtocol,
+    socketFactory = createWebSocket
+  ) {
     this._open = true
     this._pending = []
     this._error = null
@@ -44,7 +48,7 @@ export default class WebSocketChannel {
       return
     }
 
-    this._ws = createWebSocket(scheme, config.address)
+    this._ws = socketFactory(scheme, config.address)
     this._ws.binaryType = 'arraybuffer'
 
     const self = this
@@ -54,6 +58,7 @@ export default class WebSocketChannel {
       if (!e.wasClean) {
         self._handleConnectionError()
       }
+      self._open = false
     }
     this._ws.onopen = function () {
       // Connected! Cancel the connection timeout

test/internal/browser/browser-channel.test.js

@@ -24,6 +24,9 @@ import { setTimeoutMock } from '../timers-util'
 import { ENCRYPTION_OFF, ENCRYPTION_ON } from '../../../src/v1/internal/util'
 import ServerAddress from '../../../src/v1/internal/server-address'
 
+const WS_OPEN = 1
+const WS_CLOSED = 3
+
 /* eslint-disable no-global-assign */
 describe('WebSocketChannel', () => {
   let OriginalWebSocket
@@ -236,4 +239,43 @@ describe('WebSocketChannel', () => {
     expect(channel).toBeDefined()
     expect(warnMessages.length).toEqual(1)
   }
+
+  it('should set _open to false when connection closes', async () => {
+    const fakeSetTimeout = setTimeoutMock.install()
+    try {
+      // do not execute setTimeout callbacks
+      fakeSetTimeout.pause()
+      const address = ServerAddress.fromUrl('bolt://localhost:8989')
+      const driverConfig = { connectionTimeout: 4242 }
+      const channelConfig = new ChannelConfig(
+        address,
+        driverConfig,
+        SERVICE_UNAVAILABLE
+      )
+      webSocketChannel = new WebSocketChannel(
+        channelConfig,
+        undefined,
+        createWebSocketFactory(WS_OPEN)
+      )
+      webSocketChannel._ws.close()
+      expect(webSocketChannel._open).toBe(false)
+    } finally {
+      fakeSetTimeout.uninstall()
+    }
+  })
+
+  function createWebSocketFactory (readyState) {
+    const ws = {}
+    ws.readyState = readyState
+    ws.close = () => {
+      ws.readyState = WS_CLOSED
+      if (ws.onclose && typeof ws.onclose === 'function') {
+        ws.onclose({ wasClean: true })
+      }
+    }
+    return url => {
+      ws.url = url
+      return ws
+    }
+  }
 })