This module is based on the Get-Parameter function written by Hal Rottenberg, Oisin Grehan, Jason Archer, and Shay Levy, and maintained by myself over the years ...
The main functionality of this module is held in four commands. The first three here are the new ones involved in testing. The fourth is Get-Parameter which has been available as a script on the PowerShell gallery and PoshCode for over a decade and is very useful for helping you understand the available parameters of a command.
Establishes the scope of the tests for parameters of a specific command
Narrows the scope of the tests to a single parameter set
Tests that parameters exist, have certain types, etc.
Enumerates the parameters of one or more commands, returning the parameters by ParameterSet. This means there are duplicates for each parameter which exists in more than one parameter set, but this command was primarily written to help users to understand a command. For example:
PS> Get-Parameter Rename-Item
Command: Microsoft.PowerShell.Management/Rename-Item
Set: ByPath *
Name Aliases Position Mandatory Pipeline ByName Provider Type
---- ------- -------- --------- -------- ------ -------- ----
Confirm {cf} Named False False False All SwitchParameter
Credential {Cr*} Named False False True All PSCredential
Force {F*} Named False False False All SwitchParameter
NewName {N*} 1 True False True All String
PassThru {Pas*} Named False False False All SwitchParameter
Path {Pat*} 0 True True True All String
UseTransaction {usetx} Named False False False All SwitchParameter
WhatIf {wi} Named False False False All SwitchParameter
Command: Microsoft.PowerShell.Management/Rename-Item
Set: ByLiteralPath
Name Aliases Position Mandatory Pipeline ByName Provider Type
---- ------- -------- --------- -------- ------ -------- ----
Confirm {cf} Named False False False All SwitchParameter
Credential {Cr*} Named False False True All PSCredential
Force {F*} Named False False False All SwitchParameter
LiteralPath {PSPath, L*} Named True False True All String
NewName {N*} 1 True False True All String
PassThru {Pas*} Named False False False All SwitchParameter
UseTransaction {usetx} Named False False False All SwitchParameter
WhatIf {wi} Named False False False All SwitchParameter
The output allows you to tell which parameters accept values from the pipeline, and which accept parameters from the pipeline by property name. It shows which are positional, their types, and even the short form aliases (note the * on an alias indicates that is just the shortest unique form of the original parameter, not an explicit alias).
Note that in the case of commands like Get-ChildItem, it will even show parameters which are added by certain providers.
I still expect to write some additional assertions here to test for aliases, for whether parameters support valueFromPipeline, parameter validation, etc.
This should be updated with an actual common command, but for now, documentation with a function I have at work:
This first example avoids testing parameter sets explicitly by using the -AllowMissedSets switch
Test-ParametersOf -Command Import-QMTenant -AllowMissedSets {
Assert-Parameter LogFilePrefix -Type String -Mandatory:$False
Assert-Parameter ArchivePath -Type String -Mandatory
Assert-Parameter TenantID -ParameterSet SingleArchive, BackupWithRepoFiles
Assert-Parameter DatabaseBackup -Type String -Mandatory -ParameterSet BackupWithRepoFiles
Assert-Parameter RepositoryFilesFolder -Type String -Mandatory
}A more specific test of the same commands would require specifying every parameter set, and even duplicating parameters which appear in more than one parameter set unless they appear in ALL parameter sets:
Test-ParametersOf -Command Import-QMTenant {
Assert-Parameter LogFilePrefix -Type String -Mandatory:$False
Select-ParameterSet SingleArchive {
Assert-Parameter ArchivePath -Type String -Mandatory
Assert-Parameter TenantID -Type String -Mandatory
}
Select-ParameterSet BackupWithRepoFiles {
Assert-Parameter DatabaseBackup -Type String -Mandatory
Assert-Parameter RepositoryFilesFolder -Type String -Mandatory
Assert-Parameter TenantID -Type String -Mandatory
}
Select-ParameterSet ThirdParameterSet { }
}For historical reasons, here is the version history for the Get-Parameter command:
Version 0.80 - April 2008 - By Hal Rottenberg http://poshcode.org/186
Version 0.81 - May 2008 - By Hal Rottenberg http://poshcode.org/255
Version 0.90 - June 2008 - By Hal Rottenberg http://poshcode.org/445
Version 0.91 - June 2008 - By Oisin Grehan http://poshcode.org/446
Version 0.92 - April 2008 - By Hal Rottenberg http://poshcode.org/549
- ADDED resolving aliases and avoided empty output
Version 0.93 - Sept 24, 2009 - By Hal Rottenberg http://poshcode.org/1344
Version 1.0 - Jan 19, 2010 - By Joel Bennett http://poshcode.org/1592
- Merged Oisin and Hal's code with my own implementation
- ADDED calculation of dynamic paramters
Version 2.0 - July 22, 2010 - By Joel Bennett http://poshcode.org/get/2005
- CHANGED uses FormatData so the output is objects
- ADDED calculation of shortest names to the aliases (idea from Shay Levy http://poshcode.org/1982,
but with a correct implementation)
Version 2.1 - July 22, 2010 - By Joel Bennett http://poshcode.org/2007
- FIXED Help for SCRIPT file (script help must be separated from #Requires by an emtpy line)
- Fleshed out and added dates to this version history after Bergle's criticism ;)
Version 2.2 - July 29, 2010 - By Joel Bennett http://poshcode.org/2030
- FIXED a major bug which caused Get-Parameters to delete all the parameters from the CommandInfo
Version 2.3 - July 29, 2010 - By Joel Bennett
- ADDED a ToString ScriptMethod which allows queries like:
$parameters = Get-Parameter Get-Process; $parameters -match "Name"
Version 2.4 - July 29, 2010 - By Joel Bennett http://poshcode.org/2032
- CHANGED "Name" to CommandName
- ADDED ParameterName parameter to allow filtering parameters
- FIXED bug in 2.3 and 2.2 with dynamic parameters
Version 2.5 - December 13, 2010 - By Jason Archer http://poshcode.org/2404
- CHANGED format temp file to have static name, prevents bloat of random temporary files
Version 2.6 - July 23, 2011 - By Jason Archer http://poshcode.org/2815
- FIXED miscalculation of shortest unique name (aliases count as unique names),
this caused some parameter names to be thrown out (like "Object")
- CHANGED code style cleanup
Version 2.7 - November 28, 2012 - By Joel Bennett http://poshcode.org/3794
- Added * indicator on default parameter set.
Version 2.8 - August 27, 2013 - By Joel Bennett http://poshcode.org/4438
- Added SetName filter
- Add * on the short name in the aliases list (to distinguish it from real aliases)
FIXED PowerShell 4 Bugs:
- Added PipelineVariable to CommonParameters
FIXED PowerShell 3 Bugs:
- Don't add to the built-in Aliases anymore, it changes the command!
Version 2.9 - July 13, 2015 - By Joel Bennett
- FIXED (hid) exceptions when looking for dynamic parameters
- CHANGE to only search for provider parameters on Microsoft.PowerShell.Management commands (BUG??)
- ADDED SkipProviderParameters switch to manually disable looking for provider parameters (faster!)
- ADDED "Name" alias for CommandName to fix piping Get-Command output