powershell/PSAvoidNullOrEmptyHelpMessageAttribute

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

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

tally disables this rule by default for Dockerfile RUN snippets because a RUN executes statements inline rather than defining cmdlets, parameters, or modules with external callers. Re-enable it with include = ["powershell/PSAvoidNullOrEmptyHelpMessageAttribute"] or by setting rules.powershell.PSAvoidNullOrEmptyHelpMessageAttribute.severity = "warning" in .tally.toml.

Description

The value of the HelpMessage attribute should not be an empty string or a null value as this causes PowerShell’s interpreter to throw an error when executing the function or cmdlet.

How

Specify a value for the HelpMessage attribute.

Examples

Problematic code

Function BadFuncEmptyHelpMessageEmpty
{
    Param(
        [Parameter(HelpMessage='')]
        [String]
        $Param
    )

    $Param
}

Function BadFuncEmptyHelpMessageNull
{
    Param(
        [Parameter(HelpMessage=$null)]
        [String]
        $Param
    )

    $Param
}

Function BadFuncEmptyHelpMessageNoAssignment
{
    Param(
        [Parameter(HelpMessage)]
        [String]
        $Param
    )

    $Param
}

Correct code

Function GoodFuncHelpMessage
{
    Param(
        [Parameter(HelpMessage='This is helpful')]
        [String]
        $Param
    )

    $Param
}

Source

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

powershell/PSAvoidMultipleTypeAttributes

powershell/PSAvoidOverwritingBuiltInCmdlets

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​Description

​How

​Examples

​Problematic code

​Correct code

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Description

How

Examples

Problematic code

Correct code

Source