Powershell: `Test-Json` fails to parse schema while other validators succeed

[chriskuech]

Steps to reproduce

good.params.json

{
  "$schema": "https://schema.management.azure.com/schemas/2015-01-01/deploymentParameters.json#",
  "contentVersion": "0.0.0.1",
  "parameters": {
    "var1": {
      "value": "4"
    },
    "var2": {
      "reference": {
        "keyVault": {
          "id": "<keyvault-resource-id>"
        },
        "secretName": "<secret-name>"
      }
    }
  }
}

$json = Get-Content $PSScriptRoot\good.params.json -Raw
$schemaUri = ($json | ConvertFrom-Json).'$schema' -replace "#.*"
[string]$schema = Invoke-WebRequest $schemaUri
Test-Json -Json $json -Schema $schema

Expected behavior

I have tested the schema and json in two online validators and neither had issues, so I would expect Test-Json to not throw an error.

Actual behavior

Test-Json : Cannot parse the JSON schema.
At /bugrepro.ps1:4 char:1
+ Test-Json -Json $json -Schema $schema
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : InvalidData: (:) [Test-Json], Exception
+ FullyQualifiedErrorId : InvalidJsonSchema,Microsoft.PowerShell.Commands.TestJsonCommand

Environment data

Name                           Value
----                           -----
PSVersion                      6.2.0
PSEdition                      Core
GitCommitId                    6.2.0
OS                             Darwin 18.5.0 Darwin Kernel Version 18.5.…
Platform                       Unix
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1
WSManStackVersion              3.0

[savagemonitor]

It looks like this is a bug with NJsonSchema as they currently have this issue: https://github.com/RicoSuter/NJsonSchema/issues/588

What other validators did you use that succeeded?

[chriskuech]

I used a few different random ones to validate. Is there any known workaround?

[rlvandaveer]

I was working on a CI process that validates ARM templates yesterday evening and I also encountered this issue.

[chriskuech]

@PowerShellTeam , considering

• the NJsonSchema bug basically renders this cmdlet useless
• the NJsonSchema bug is very stale with no recent responses from their team
• PowerShell already contains references to Newtonsoft

Would you consider updating this cmdlet to use Json.NET instead of NJsonSchema?

[AdamCoulterOz]

This really needs to be fixed regardless of the "external" dependencies. You offer a service which includes choices made on libraries you use. If the library doesn't work anymore, then you need to respond and fix it in another way. @chriskuech seems to have an option which could help.

[iSazonov]

Anyщтн could contribute to NJsonSchema.

[MalcolmTyrrell]

FYI, the issue at NJsonSchema (https://github.com/RicoSuter/NJsonSchema/issues/588) has been fixed.

[iSazonov]

We will get this with follow NJsonSchema release.