Change ConvertFrom-Json -AsHashtable to use ordered hashtable

[SteveL-MSFT]

PR Summary

JSON typically has ordering to make it easier to read. Currently, a Hashtable does not preserve ordering so for complex JSON, the members are not where you would expect in terms of order. This change wraps OrderedDictionary into a OrderedHashtable that derives from Hashtable. This preserves existing compatibility with scripts that expect a Hashtable to be returned, but preserves the order of elements.

PR Context

Fix #17404

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[SteveL-MSFT]

Going to rework this as additional -AsOrderedDictionary switch

[ghost]

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[PaulHigin]

This implementation seems unusual to me. Everything is computed as an ordered dictionary, but then at the end converted to a Hashtable type if requested. Why not just have two code paths, one for Hashtable switch and one for Ordered switch?

[strawgate]

PS> compare-object (@{} | get-member).name ([ordered]@{} | get-member).name

InputObject   SideIndicator
-----------   -------------
AsReadOnly    =>
Insert        =>
RemoveAt      =>
Clone         <=
ContainsKey   <=
ContainsValue <=

System.Collections.Specialized.OrderedDictionary has 3 extra methods, Insert,RemoveAt, AsReadOnly but is missing Clone, ContainsKey, and ContainsValue when compared to System.Collections.Hashtable

Given the ubiquity of ContainsKey and ContainsValue when dealing with Hashtables I think this is probably a very large breaking change if it does not sit behind a -switch on the cmdlet so I also vote for having it as a switch (not that I get a vote).

[ghost]

This pull request has been automatically marked as stale because it has been marked as requiring author feedback but has not had any activity for 15 days. It will be closed if no further activity occurs within 10 days of this comment.

[SteveL-MSFT]

CI bootstrap issue is dotnet-install.sh no longer working, created dotnet/install-scripts#285

[SteveL-MSFT]

@PaulHigin can you take another look, decided instead of a separate switch for Hashtable vs OrderedDictionary, just wrap OrderedDictionary as OrderedHashtable to preserve compatibility

[ghost]

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Maintainer, please provide feedback and/or mark it as Waiting on Author

[jhoneill]

There are multiple ways that the order of data might be valuable, so losing that is a negative and changing to keep it is a positive. There's just a question of possible breakages, and since Windows PowerShell didn't have the -AsHashTable switch changing its behaviour doesn't affect 15 years' worth of scripts. Anything which uses it in PowerShell 6 /7 is able to work with the items in any order so if the order is the original order it doesn't matter. A few things can't work with the randomized order or need to do extra work.

One pitfall is side stepped by using this new ordered hashtable instead of an ordered dictionary - anything that checks inpu with -is [hashtable] won't be affected (something which checks the full type as a string might be). Unless there's an argument against doing this that I've missed it seems like all positives, no negatives.

[iSazonov]

@SteveL-MSFT Need rebase to pass Unix tests?

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🎉v7.3.0-preview.6 has been released which incorporates this pull request.:tada:

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