AvoidNullOrEmptyHelpMessageAttribute.md

Pattern: Use of null or empty HelpMessage attribute

Issue: -

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.

Example

Example of incorrect 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
}

Example of correct code:

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

	$Param
}

Further Reading

• PSScriptAnalyzer - AvoidNullOrEmptyHelpMessageAttribute