[forge-issues] [JBoss JIRA] (FORGE-763) ShellImpl "noInitMode" concept mismanages completers

ShellImpl "noInitMode" concept mismanages completers ---------------------------------------------------- Key: FORGE-763 URL: https://issues.jboss.org/browse/FORGE-763 Project: Forge Issue Type: Bug Components: Shell Affects Versions: 1.2.0.Final Reporter: Matt Benson Assignee: Matt Benson Fix For: 1.2.1.Final The _concept_ at work in the current code is that a number of completers are set up when the {{ShellImpl#init()}} {{Startup}} observer is called (that number currently happens to be 1--the instance of {{PluginCommandCompleter}} that is also passed to the {{Startup}} observer). These are added to an {{AggregateCompleter}} and stored as an instance variable of the {{ShellImpl}}. At the same time, if the shell is determined to be in {{noInitMode}}, these (1) completers are added to a list deemed {{_deferredCompleters}}. The idea is that in {{noInitMode}} the reader will not be known at {{init}} time. Unfortunately, there are a number of implementation problems: * the method that eventually accomplishes setting the completer on the reader, {{_initCompleters()}} is parameterized with a completer, but this completer is never used in the body of the method. Instead, the completer member is sent. * the {{_deferredCompleters}} list is only initialized if it is null. In the test scenario, the result of this is that the list grows by one repeated instance of the same {{PluginCommandCompleter}} for every {{@Test}} method executed in a given unit test class. * the {{noInitMode}} portion of {{initReadersAndStreams()}} calls {{_initCompleters()}} once per element of {{_deferredCompleters}}; this has two effects: it sets the completion handler on the reader multiple times (which is only wasteful), and it adds the instance-bound completer multiple times. As a result, when e.g. {{#promptWithCompleter()}} temporarily removes the shell's completer, there are still {{n}} remaining copies of the same instance hanging around. If the two identified oddities with the current code are fixed, a new issue arises: now, the deferred completers are added individually to the reader. When {{#promptWithCompleter()}} attempts to remove the instance-bound completer from the reader, nothing happens as this is an {{AggregateCompleter}} wrapping the lone deferred completer, which was itself added to the reader. Thus, any deferment to be done must still be done with the {{AggregateCompleter}}, obviating the deferred completers concept entirely.