Disable secure connection warning when the window.protocol is not available (#664)

The window.location is not available in the WebWorkers contexts and because of the driver keeps wrongly warning about a misconfiguration.
If the information location protocol is not available, the driver should not warning.

Author: bigmontz

src/internal/browser/browser-channel.js

@@ -323,7 +323,9 @@ function isProtocolSecure (protocolSupplier) {
 }
 
 function verifyEncryptionSettings (encryptionOn, encryptionOff, secureProtocol) {
-  if (encryptionOn && !secureProtocol) {
+  if (secureProtocol === null) {
+    // do nothing sice the protocol could not be identified
+  } else if (encryptionOn && !secureProtocol) {
     // encryption explicitly turned on for a driver used on a HTTP web page
     console.warn(
       'Neo4j driver is configured to use secure WebSocket on a HTTP web page. ' +

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

@@ -142,6 +142,24 @@ describe('#unit WebSocketChannel', () => {
     testWarningInMixedEnvironment(ENCRYPTION_OFF, 'https')
   })
 
+  it('should generate not warning when encryption turned and the protocol could not be fetched', () => {
+    testWarningInMixedEnvironment(true, null, warnMessages =>
+      expect(warnMessages.length).toBe(0)
+    )
+    testWarningInMixedEnvironment(ENCRYPTION_ON, null, warnMessages =>
+      expect(warnMessages.length).toBe(0)
+    )
+  })
+
+  it('should generate a warning when encryption turned off and the protocol could not be fetched', () => {
+    testWarningInMixedEnvironment(false, null, warnMessages =>
+      expect(warnMessages.length).toBe(0)
+    )
+    testWarningInMixedEnvironment(ENCRYPTION_OFF, null, warnMessages =>
+      expect(warnMessages.length).toBe(0)
+    )
+  })
+
   it('should resolve close if websocket is already closed', async () => {
     const address = ServerAddress.fromUrl('bolt://localhost:8989')
     const channelConfig = new ChannelConfig(address, {}, SERVICE_UNAVAILABLE)
@@ -216,7 +234,11 @@ describe('#unit WebSocketChannel', () => {
     expect(channel._ws.url).toEqual(expectedScheme + '://localhost:8989')
   }
 
-  function testWarningInMixedEnvironment (encrypted, scheme) {
+  function testWarningInMixedEnvironment (
+    encrypted,
+    scheme,
+    assertWarnMessage = warnMessages => expect(warnMessages.length).toEqual(1)
+  ) {
     const originalConsoleWarn = console.warn
     try {
       // replace console.warn with a function that memorizes the message
@@ -229,7 +251,7 @@ describe('#unit WebSocketChannel', () => {
         { encrypted: encrypted },
         SERVICE_UNAVAILABLE
       )
-      const protocolSupplier = () => scheme + ':'
+      const protocolSupplier = () => (scheme != null ? scheme + ':' : scheme)
 
       const channel = new WebSocketChannel(
         config,
@@ -238,7 +260,7 @@ describe('#unit WebSocketChannel', () => {
       )
 
       expect(channel).toBeDefined()
-      expect(warnMessages.length).toEqual(1)
+      assertWarnMessage(warnMessages)
     } finally {
       console.warn = originalConsoleWarn
     }