Jira (PUP-9400) Puppet Parser cannot handle "case $:xxx:{ default: {} }" block

[Alex Siryi (JIRA)]

Title: Message Title

Alex Siryi created an issue   Puppet / PUP-9400 Puppet Parser cannot handle "case $:xxx:{ default: {} }" block Issue Type: Bug Affects Versions: PUP 6.1.0 Assignee: Unassigned Attachments: puppet_crash_stacktrace.txt, puppet-parser-test-current.rb, puppet-parser-test-fixed.rb Components: CLI Created: 2019/01/06 4:57 AM Environment: No puppet server whatsoever, just puppet as a ruby script Labels: parser Priority: Minor Reporter: Alex Siryi Puppet Version: 6.1.0 Puppet Server Version: does not apply** OS Name/Version: Windows but does not apply I am using puppet internals (puppet parser) to parse puppet manifests into JSON (puppet structured AST). I have noticed that PNTransformer cannot transform this block  class breakme { case "test" { default: {} } } into JSON and crashes  Visitor Error: the configured receiver (Puppet::Pops::Model::PNTransformer) can't handle instance of: NilClass (RuntimeError) (see crash stack trace attached).   The reason of this is because the instruction pretty much produces nothing AND PNTransformer has no method to visit the transform_NilClass (puppet server even thinks it's illegal, This 'case' statement has no effect.). However, the instruction being illegal is irrelevant, as the puppet parser has to parse the AST structure correctly anyway.   Please see the puppet-parser-test-current.rb and puppet-parser-test-fixed.rb as self-containing examples Desired Behavior: **It should resolve the default section into, for example, a "nop" instruction: {"^":["class",{"#":["name","breakme","body",[{"^":["case","test",[{"#":["when",[{"^":["default"]}],"then",[{"^":["nop"]}]]}]]}]]}]} Actual Behavior: **It crashes with Visitor Error: the configured receiver (Puppet::Pops::Model::PNTransformer) can't handle instance of: NilClass (RuntimeError)   Solution: The solution would be to add this method to the PNTransformer class: class Puppet::Pops::Model::PNTransformer def transform_NilClass(e) Puppet::Pops::PN::Call.new('nop') end end  Or, it should raise appropriate exception of the _expression_ being illegal, instead of crashing Add Comment   This message was sent by Atlassian JIRA (v7.7.1#77002-sha1:e75ca93) -- You received this message because you are subscribed to the Google Groups "Puppet Bugs" group. To unsubscribe from this group and stop receiving emails from it, send an email to puppet-bugs+unsubscr...@googlegroups.com. To post to this group, send email to puppet-bugs@googlegroups.com. Visit this group at https://groups.google.com/group/puppet-bugs. For more options, visit https://groups.google.com/d/optout.