Powershell: ConvertFrom-Json tolerates non-standard JSON -- consider a -Strict flag

[AurimasNav]

Steps to reproduce

>"{'key':'value',}" | ConvertFrom-Json

Expected behavior

expecting pwsh to throw an exception just like powershell 5.1

ConvertFrom-Json : Invalid JSON primitive: .
At line:1 char:22
+ "{'key':'value',}" | ConvertFrom-Json
+                      ~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [ConvertFrom-Json], ArgumentException
    + FullyQualifiedErrorId : System.ArgumentException,Microsoft.PowerShell.Commands.ConvertFromJsonCommand

Actual behavior

>"{'key':'value',}" | ConvertFrom-Json

key
---
value

Environment data

Name                           Value
----                           -----
PSVersion                      7.0.3
PSEdition                      Core
GitCommitId                    7.0.3
OS                             Microsoft Windows 10.0.18363
Platform                       Win32NT
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

I would expect pwsh 7 to throw in this case just like powershell 5.1 does, in a case where I need to pass this json string down to some other tool I can't validate it using pwsh which I was able to do with powershell 5.1, I've laso tried Test-Json which behaves consistently:

> "{'key':'value',}" | Test-Json
True

[rjmholt]

This is probably due to Newtonsoft.Json being tolerant and not being configured to reject input like this. If we've been permissive like this, it's possible someone now depends on it, but changing it would strike me as a bucket 3 breaking change

[iSazonov]

We will consider this during migration to the new .Net JSON API.

[rjmholt]

We will consider this during migration to the new .Net JSON API.

Yeah this is the kind of change that would occur with that migration. In this case I think it's acceptable. Although perhaps in the case of something like comments in the JSON or trailing commas, we might have compatibility issues that we need to investigate.

[BrucePay]

Maybe we should add a '-Strict' flag.

[Serg046]

Duplicate of https://github.com/PowerShell/PowerShell/issues/11117.
Newtonsoft.Json doesn't support trailing comma validation. If we need this, we will have to write a custom JsonTextReader.

[iSazonov]

Dup #10628

[msftbot[bot]]

This issue has been marked as duplicate and has not had any activity for 1 day. It has been closed for housekeeping purposes.