powershell/PSDSCReturnCorrectTypesForDSCFunctions

powershell/PSDSCReturnCorrectTypesForDSCFunctions is a PSScriptAnalyzer diagnostic emitted by tally for PowerShell snippets embedded in Dockerfiles.

Property	Value
Severity	Information
Category	PSScriptAnalyzer
Default	Disabled in tally
Auto-fix	No

tally disables this rule by default because Desired State Configuration resources are out of scope for Dockerfile RUN analysis. Re-enable it with include = ["powershell/PSDSCReturnCorrectTypesForDSCFunctions"] or by setting rules.powershell.PSDSCReturnCorrectTypesForDSCFunctions.severity = "warning" in .tally.toml.

Description

The functions in DSC resources have specific return objects. For non-class based resources:

Set-TargetResource must not return any value.
Test-TargetResource must return a boolean.
Get-TargetResource must return a hash table.

For class based resources:

Set must not return any value.
Test must return a boolean.
Get must return an instance of the DSC class.

How

Ensure that each function returns the correct type.

Example 1

Problematic code

function Get-TargetResource
{
    param
    (
        [parameter(Mandatory = $true)]
        [String]
        $Name
    )
    ...
}

function Set-TargetResource
{
    param
    (
        [parameter(Mandatory = $true)]
        [String]
        $Name
    )
    ...
}

function Test-TargetResource
{
    param
    (
        [parameter(Mandatory = $true)]
        [String]
        $Name
    )
    ...
}

Correct code

function Get-TargetResource
{
    [OutputType([Hashtable])]
    param
    (
        [parameter(Mandatory = $true)]
        [String]
        $Name
    )
    ...
}

function Set-TargetResource
{
    param
    (
        [parameter(Mandatory = $true)]
        [String]
        $Name
    )
    ...
}

function Test-TargetResource
{
    [OutputType([System.Boolean])]
    param
    (
        [parameter(Mandatory = $true)]
        [String]
        $Name
    )
    ...
}

Example 2

Problematic code

[DscResource()]
class MyDSCResource
{
    [DscProperty(Key)]
    [string] $Name

    [String] Get()
    {
        ...
    }

    [String] Set()
    {
        ...
    }

    [bool] Test()
    {
        ...
    }
}

Correct code

[DscResource()]
class MyDSCResource
{
    [DscProperty(Key)]
    [string] $Name

    [MyDSCResource] Get()
    {
        ...
    }

    [void] Set()
    {
        ...
    }

    [bool] Test()
    {
        ...
    }
}

Source

This rule documentation is adapted from Microsoft’s PSScriptAnalyzer documentation for DSCReturnCorrectTypesForDSCFunctions, licensed under CC BY 4.0.

Overview

Security

Correctness

Performance

JavaScript

Style

Labels

GPU / CUDA

PHP

Ruby

PowerShell

Windows

BuildKit Rules

Hadolint Rules

ShellCheck Rules

powershell/PSDSCReturnCorrectTypesForDSCFunctions

Description

How

Example 1

Problematic code

Correct code

Example 2

Problematic code

Correct code

Source

​Description

​How

​Example 1

​Problematic code

​Correct code

​Example 2

​Problematic code

​Correct code

​Source

Description

How

Example 1

Problematic code

Correct code

Example 2

Problematic code

Correct code

Source