Skip to main content
Version: v6

Should-HaveParameter

This page was generated

Contributions are welcome in Pester-repo.

SYNOPSIS​

Asserts that a command has the expected parameter.

SYNTAX​

Should-HaveParameter [[-ParameterName] <string>] [[-Type] <Object>] [[-DefaultValue] <string>]
 [[-InParameterSet] <string>] [[-Alias] <string[]>] [[-Actual] <Object>] [[-Because] <string>]
 [-Mandatory] [-HasArgumentCompleter]

DESCRIPTION​

This assertion inspects command metadata and can also verify parameter details such as type, default value, aliases, parameter set membership, mandatory status, and argument completers.

EXAMPLES​

EXAMPLE 1​

Get-Command Invoke-WebRequest | Should-HaveParameter Uri -Type ([uri]) -Mandatory

This assertion passes, because Invoke-WebRequest has a mandatory -Uri parameter of type [uri].

EXAMPLE 2​

function Get-Cat {
    [CmdletBinding(DefaultParameterSetName = 'ByName')]
    param(
        [Parameter(ParameterSetName = 'ByName', Mandatory)]
        [Alias('Id')]
        [string] $Name,

[Parameter(ParameterSetName = 'ByIndex', Mandatory)]
        [int] $Index,

        [ValidateSet('Json', 'Xml')]
        [string] $Format = 'Json'
    )
}

Describe 'Get-Cat public contract' {
    It 'requires a Name' {
        Get-Command Get-Cat | Should-HaveParameter Name -Type ([string]) -Mandatory -Alias 'Id'
    }

    It 'defaults Format to Json' {
        Get-Command Get-Cat | Should-HaveParameter Format -Type ([string]) -DefaultValue 'Json'
    }
}

A typical real-life use is locking down the public API of your own command. These assertions pass, because -Name is a mandatory [string] with the alias Id, and -Format is an optional [string] that defaults to Json.

EXAMPLE 3​

Get-Command Get-Cat | Should-HaveParameter Index -InParameterSet 'ByIndex'

This assertion passes, because the -Index parameter (from the Get-Cat function above) belongs to the ByIndex parameter set.

PARAMETERS​

-Actual​

The actual command to check. E.g. Get-Command "Invoke-WebRequest"

Type: System.Object
DefaultValue: ''
SupportsWildcards: false
Aliases: []
ParameterSets:
- Name: (All)
  Position: 5
  IsRequired: false
  ValueFromPipeline: true
  ValueFromPipelineByPropertyName: false
  ValueFromRemainingArguments: false
DontShow: false
AcceptedValues: []
HelpMessage: ''

-Alias​

The alias of the parameter to check.

Type: System.String[]
DefaultValue: ''
SupportsWildcards: false
Aliases: []
ParameterSets:
- Name: (All)
  Position: 4
  IsRequired: false
  ValueFromPipeline: false
  ValueFromPipelineByPropertyName: false
  ValueFromRemainingArguments: false
DontShow: false
AcceptedValues: []
HelpMessage: ''

-Because​

The reason why the input should be the expected value.

Type: System.String
DefaultValue: ''
SupportsWildcards: false
Aliases: []
ParameterSets:
- Name: (All)
  Position: 6
  IsRequired: false
  ValueFromPipeline: false
  ValueFromPipelineByPropertyName: false
  ValueFromRemainingArguments: false
DontShow: false
AcceptedValues: []
HelpMessage: ''

-DefaultValue​

The default value of the parameter to check. E.g. "https://example.com"

Type: System.String
DefaultValue: ''
SupportsWildcards: false
Aliases: []
ParameterSets:
- Name: (All)
  Position: 2
  IsRequired: false
  ValueFromPipeline: false
  ValueFromPipelineByPropertyName: false
  ValueFromRemainingArguments: false
DontShow: false
AcceptedValues: []
HelpMessage: ''

-HasArgumentCompleter​

Whether the parameter has an argument completer or not.

Type: System.Management.Automation.SwitchParameter
DefaultValue: False
SupportsWildcards: false
Aliases: []
ParameterSets:
- Name: (All)
  Position: Named
  IsRequired: false
  ValueFromPipeline: false
  ValueFromPipelineByPropertyName: false
  ValueFromRemainingArguments: false
DontShow: false
AcceptedValues: []
HelpMessage: ''

-InParameterSet​

The parameter set that the parameter belongs to.

Type: System.String
DefaultValue: ''
SupportsWildcards: false
Aliases: []
ParameterSets:
- Name: (All)
  Position: 3
  IsRequired: false
  ValueFromPipeline: false
  ValueFromPipelineByPropertyName: false
  ValueFromRemainingArguments: false
DontShow: false
AcceptedValues: []
HelpMessage: ''

-Mandatory​

Whether the parameter is mandatory or not.

Type: System.Management.Automation.SwitchParameter
DefaultValue: False
SupportsWildcards: false
Aliases: []
ParameterSets:
- Name: (All)
  Position: Named
  IsRequired: false
  ValueFromPipeline: false
  ValueFromPipelineByPropertyName: false
  ValueFromRemainingArguments: false
DontShow: false
AcceptedValues: []
HelpMessage: ''

-ParameterName​

The name of the parameter to check. E.g. Uri

Type: System.String
DefaultValue: ''
SupportsWildcards: false
Aliases: []
ParameterSets:
- Name: (All)
  Position: 0
  IsRequired: false
  ValueFromPipeline: false
  ValueFromPipelineByPropertyName: false
  ValueFromRemainingArguments: false
DontShow: false
AcceptedValues: []
HelpMessage: ''

-Type​

The type of the parameter to check. E.g. [string]

Type: System.Object
DefaultValue: ''
SupportsWildcards: false
Aliases: []
ParameterSets:
- Name: (All)
  Position: 1
  IsRequired: false
  ValueFromPipeline: false
  ValueFromPipelineByPropertyName: false
  ValueFromRemainingArguments: false
DontShow: false
AcceptedValues: []
HelpMessage: ''

CommonParameters​

This cmdlet supports the common parameters: -Debug, -ErrorAction, -ErrorVariable, -InformationAction, -InformationVariable, -OutBuffer, -OutVariable, -PipelineVariable, -ProgressAction, -Verbose, -WarningAction, and -WarningVariable. For more information, see about_CommonParameters.

INPUTS​

System.Object​

OUTPUTS​

NOTES​

The attribute [ArgumentCompleter] was added with PSv5. Previously this assertion will not be able to use the -HasArgumentCompleter parameter if the attribute does not exist.

Use the -ErrorAction parameter to control soft-assertion behavior for this assertion. -ErrorAction Continue records the failure and lets the rest of the test run (a soft assertion), while -ErrorAction Stop fails the test immediately, for example to guard a precondition before continuing.

When -ErrorAction is not specified, the behavior comes from Should.ErrorAction in the configuration, which defaults to Stop. See https://pester.dev/docs/assertions/soft-assertions for more about soft assertions.

VERSION​

This page was generated using comment-based help in Pester 6.0.0.