Jira (PUP-9305) Built-in unique function behaves differently with undef
Title: Message Title Austin Boyd updated an issue Puppet / PUP-9305 Built-in unique function behaves differently with undef Change By: Austin Boyd Zendesk Ticket IDs: 33515 Zendesk Ticket Count: 1 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 view this discussion on the web visit https://groups.google.com/d/msgid/puppet-bugs/JIRA.284270.1541619277000.6391.1576158540291%40Atlassian.JIRA.
Jira (PUP-9305) Built-in unique function behaves differently with undef
Title: Message Title
Henrik Lindberg commented on PUP-9305
Re: Built-in unique function behaves differently with undef
Sean Millichamp That is what I am leaning towards (not changing) since "give me a unique set of undef" is a strange thing to ask for and most likely masks some other problem if it was to return undef. We had a similar request to make empty() accept undef and return true - there we had lots of breakage of legacy code when it did not accept undef, and it seemed reasonably harmless to allow that even if you can argue that undef is indeed undefined and you cannot even know if it is something "empty or not". OTOH, undef is often referred to as "the empty set". In this case (for unique) this ticket was filed long after 5.0.0 was released - so cannot be a common problem and is easily avoided by using type checking. You can argue that if undef is indeed "the empty set", then a unique should return that empty set - e.g. an empty array. But, if undef represents the "empty set", then it would be reasonable to return undef - but the problem with returning undef is that it should return something that is iterable (for example a String if given a String, and that works also on an empty string). So to comply with that requirement it would need to return an empty iterable (for example an empty Array). So, my position is:
I don't like the idea of turning undef into an Array since I think this masks a problem
I don't like the idea of turning undef into undef since it will move the error to where you try to iterate over the undef result - so this goes against "catch the error early"
I don't like making undef iterable as if it was an empty array - I think that would just mask other errors and move the problem making it more difficult to find the cause.
If accepting something like Optional[Array] and wanting to do a unique it is easy to use conditional logic or calling then
# Three different ways to check with conditional logic
$result = if $maybe_an_array =~ Array { $maybe_an_array.unique } # results in undef if not an array
$result = $maybe_an_array ? { Array => $maybe_an_array.unique, default => undef }
$result = $maybe_an_array.then |$x| { $x.unique }
Jira (PUP-9305) Built-in unique function behaves differently with undef
Title: Message Title Sean Millichamp commented on PUP-9305 Re: Built-in unique function behaves differently with undef Just wanted to add my $0.02: I wish more of the stdlib functions handled types more strictly than they have and I think the behavior of the core unique makes a lot more sense. If I call unique on something I expect that it will be an array. If it is not an array then I probably haven't handled something correctly earlier in the code (either a bug or failed to validate input correctly) and I would want it to raise an error. Please don't change the core unique behavior as added in Puppet 5. It is the right direction for the language/platform. 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.
Jira (PUP-9305) Built-in unique function behaves differently with undef
Title: Message Title Henrik Lindberg commented on PUP-9305 Re: Built-in unique function behaves differently with undef Erik Hansen Well stdlib version of the unique function turns undef into empty string - so would not be exactly the same thing. I looked at that PR and made two comments there. 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.
Jira (PUP-9305) Built-in unique function behaves differently with undef
Title: Message Title Erik Hansen commented on PUP-9305 Re: Built-in unique function behaves differently with undef Henrik Lindberg - undef for undef is I think what we want, since that's what the stdlib function does – unless you think this is an issue with my code that was masked by the stdlib version? Some added context - we originally saw this in some acceptance testing which caused a hard failure with the new function, the stdlib function would pass the test without issues. More context here: https://github.com/puppetlabs/puppet_metrics_dashboard/pull/11 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.
Jira (PUP-9305) Built-in unique function behaves differently with undef
Title: Message Title Henrik Lindberg assigned an issue to Henrik Lindberg Puppet / PUP-9305 Built-in unique function behaves differently with undef Change By: Henrik Lindberg Assignee: Henrik Lindberg 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.
Jira (PUP-9305) Built-in unique function behaves differently with undef
Title: Message Title Henrik Lindberg commented on PUP-9305 Re: Built-in unique function behaves differently with undef We can make the unique function in core return undef when getting an undef value, although it is strange to call unique in the first place on an undef value (since something has probably gone wrong?). It works in the stdlib version since undef is given to a 3.x function as an empty string and unique constructs a new string with unique characters from that string - so the result is an empty string. It would be strange if the core unique function returned an empty string when given an undef value, but returning undef or possibly an empty array would be fine. PUP-7620 added the core unique function for Puppet 5.0.0 so technically it is allowed to break API (even if this was unintentional). Erik Hansen Is it ok to fix this by returning undef for undef ? 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.
Jira (PUP-9305) Built-in unique function behaves differently with undef
Title: Message Title
Erik Hansen updated an issue
Puppet / PUP-9305
Built-in unique function behaves differently with undef
Change By:
Erik Hansen
The unique function introduced in PUP-7620 introduces a possible breaking change, as it behaves differently than the stdlib function when passed an undef value.h5. Reproduction:With the following manifest, unique.pp: {code:java} $unique = unique($this_is_undef)notice($unique){code}With stdlib installed (puppet apply unique.pp):{code:java} Warning: Unknown variable: 'this_is_undef'. at /root/unique.pp:1:22Notice: Scope(Class[main]): Notice: Compiled catalog for pe-2016413-master.puppetdebug.vlan in environment production in 0.19 secondsNotice: Applied catalog in 0.33 seconds{code}Without stdlib installed:{code:java} Warning: Unknown variable: 'this_is_undef'. (file: /root/unique.pp, line: 1, column: 22)Error: Evaluation Error: Error while evaluating a Function Call, 'unique' expects one of: (String string, Callable[String] block?) rejected: parameter 'string' expects a String value, got Undef (Hash hash, Callable[Any] block?) rejected: parameter 'hash' expects a Hash value, got Undef (Array array, Callable[Any] block?) rejected: parameter 'array' expects an Array value, got Undef (Iterable iterable, Callable[Any] block?) rejected: parameter 'iterable' expects an Iterable value, got Undef (file: /root/unique.pp, line: 1, column: 15) on node pe-201813-master.puppetdebug.vlan{code}
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Jira (PUP-9305) Built-in unique function behaves differently with undef
Title: Message Title Erik Hansen created an issue Puppet / PUP-9305 Built-in unique function behaves differently with undef Issue Type: Bug Assignee: Unassigned Created: 2018/11/07 11:34 AM Priority: Normal Reporter: Erik Hansen The unique function introduced in PUP-7620 introduces a possible breaking change, as it behaves differently than the stdlib function when passed an undef value. Reproduction: With the following manifest, unique.pp: $unique = unique($this_is_undef) notice($unique) With stdlib installed (puppet apply unique.pp): Warning: Unknown variable: 'this_is_undef'. at /root/unique.pp:1:22 Notice: Scope(Class[main]):
