Invalid MOF definition when having an Instance[]

[raandree]

Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues.

Steps to reproduce

Reproduction of the issue was done with the resource DnsServerRootHint in DnsServerDsc.

When passing values to a parameter defined as array and `EmbeddedInstance("MSFT_KeyValuePair")], compiling the following configuration.

This issue is related to #126.

ipmo PSDesiredStateConfiguration -Force

$rootHints = @{
 'A.ROOT-SERVERS.NET.' = '2001:503:ba3e::2:30'
 'B.ROOT-SERVERS.NET.' = '2001:500:84::b'
}

configuration RootHintsConfig {
 Import-DscResource -ModuleName DnsServerDsc

 DnsServerRootHint xRootHints
 {
 IsSingleInstance = 'Yes'
 NameServer = $rootHints
 }
}

results in this invalid MOF file. Note that the parameter NameServer is an array but it is lacking the curly braces.

/*
@TargetNode='localhost'
@GeneratedBy=randr
@GenerationDate=08/11/2025 22:39:07
@GenerationHost=RAANDREE1
*/

instance of MSFT_KeyValuePair as $MSFT_KeyValuePair1ref
{
Key = "B.ROOT-SERVERS.NET.";
 Value = "2001:500:84::b";

};

instance of MSFT_KeyValuePair as $MSFT_KeyValuePair2ref
{
Key = "A.ROOT-SERVERS.NET.";
 Value = "2001:503:ba3e::2:30";

};

instance of DSC_DnsServerRootHint as $DSC_DnsServerRootHint1ref
{
IsSingleInstance = "Yes";
 ResourceID = "[DnsServerRootHint]xRootHints";
 ModuleVersion = "3.0.0";
 SourceInfo = "D:\\Git\\CommonTasks\\tests\\x.ps1::11::5::DnsServerRootHint";
 NameServer = $MSFT_KeyValuePair1ref,
 $MSFT_KeyValuePair2ref
;
 ModuleName = "DnsServerDsc";

 ConfigurationName = "RootHintsConfig";

};
instance of OMI_ConfigurationDocument


 {
 Version="2.0.0";


 MinimumCompatibleVersion = "1.0.0";


 CompatibleVersionAdditionalProperties= {"Omi_BaseResource:ConfigurationName"};


 Author="randr";


 GenerationDate="08/11/2025 22:39:07";


 GenerationHost="RAANDREE1";


 Name="RootHintsConfig";


 };

A correct MOF file would look like this:

/*
@TargetNode='localhost'
@GeneratedBy=randr
@GenerationDate=08/11/2025 23:00:24
@GenerationHost=RAANDREE1
*/

instance of MSFT_KeyValuePair as $MSFT_KeyValuePair1ref
{
Key = "A.ROOT-SERVERS.NET.";
 Value = "2001:503:ba3e::2:30";

};

instance of MSFT_KeyValuePair as $MSFT_KeyValuePair2ref
{
Key = "B.ROOT-SERVERS.NET.";
 Value = "2001:500:84::b";

};

instance of DSC_DnsServerRootHint as $DSC_DnsServerRootHint1ref
{
SourceInfo = "D:\\Git\\CommonTasks\\tests\\x.ps1::11::5::DnsServerRootHint";
 ModuleVersion = "3.0.0";
 NameServer = {
 $MSFT_KeyValuePair1ref,
 $MSFT_KeyValuePair2ref

};
 IsSingleInstance = "Yes";
 ModuleName = "DnsServerDsc";
 ResourceID = "[DnsServerRootHint]xRootHints";

 ConfigurationName = "RootHintsConfig";

};
instance of OMI_ConfigurationDocument


 {
 Version="2.0.0";


 MinimumCompatibleVersion = "1.0.0";


 CompatibleVersionAdditionalProperties= {"Omi_BaseResource:ConfigurationName"};


 Author="randr";


 GenerationDate="08/11/2025 23:00:24";


 GenerationHost="RAANDREE1";


 Name="RootHintsConfig";


 };

Expected behavior

Correct MOF file to be creaetd.

Actual behavior

MOF file has a syntax error.

Error details

PSMessageDetails : 
Exception : System.InvalidOperationException: Invalid MOF definition for node 'localhost': Exception 
 calling "ValidateInstanceText" with "1" argument(s): "Syntax error: 
 At line:26, char:40
 Buffer:
 $MSFT_KeyValuePair1ref,^
 $M
 "
TargetObject : 
CategoryInfo : InvalidOperation: (:) [Write-Error], InvalidOperationException
FullyQualifiedErrorId : InvalidMOFDefinition,Write-NodeMOFFile
ErrorDetails : Invalid MOF definition for node 'localhost': Exception calling "ValidateInstanceText" with 
 "1" argument(s): "Syntax error: 
 At line:26, char:40
 Buffer:
 $MSFT_KeyValuePair1ref,^
 $M
 "
InvocationInfo : System.Management.Automation.InvocationInfo
ScriptStackTrace : at Write-NodeMOFFile, D:\Git\CommonTasks\output\RequiredModules\PSDesiredStateConfiguration\2 
 .0.7\PSDesiredStateConfiguration.psm1: line 2954
 at Configuration, D:\Git\CommonTasks\output\RequiredModules\PSDesiredStateConfiguration\2.0.7 
 \PSDesiredStateConfiguration.psm1: line 2236
 at <ScriptBlock>, D:\Git\CommonTasks\tests\x.ps1: line 8
 at <ScriptBlock>, D:\Git\CommonTasks\tests\x.ps1: line 18
 at <ScriptBlock>, <No file>: line 1
PipelineIterationInfo : {0, 0}

Environment data

Name Value
---- -----
PSVersion 7.5.2
PSEdition Core
GitCommitId 7.5.2
OS Microsoft Windows 10.0.26100
Platform Win32NT
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0

Version

Crescendo?

Visuals

No response