Causal error not reported for datasource connection test failure in web console in JBoss EAP

Issue

• An invalid (e.g. misspelled) user is specified in a datasource configuration

• When testing datasource connectivity, the web console reports a generic error which provides no indication of the root cause

  WFLYJCA0040: failed to invoke operation: WFLYJCA0047: Connection is not valid
  

• The causal error can be found by opening the server.log

  ... WARN  [org.jboss.jca.core.connectionmanager.pool.strategy.OnePool] (External Management Request Threads -- 1) IJ000604: Throwable while attempting to get a new connection: null: javax.resource.ResourceException: IJ031084: Unable to create connection
      at org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory.createLocalManagedConnection(LocalManagedConnectionFactory.java:345)
      ...
  Caused by: java.sql.SQLException: Access denied for user 'notme'@'localhost' (using password: YES)
      at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:129)
      ...
      at org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory.createLocalManagedConnection(LocalManagedConnectionFactory.java:321)
      ...
  

• or

    ...
Caused by: javax.resource.ResourceException: IJ031087: Failed to register DriverClass for: com.mysql.cj.jdbc.Driver
    at org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory.getDriver(LocalManagedConnectionFactory.java:604)
    at org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory.createLocalManagedConnection(LocalManagedConnectionFactory.java:320)
    ... 39 more
Caused by: java.lang.ClassNotFoundException: com.mysql.cj.jdbc.Driver from [Module "deployment.mysql-connector-java-xxx-bin.jar" from Service Module Loader]
    at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:255)
    at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:410)
    at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:398)
    at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:116)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at org.jboss.jca.adapters.jdbc.local.LocalManagedConnectionFactory.getDriver(LocalManagedConnectionFactory.java:595)
    ... 40 more