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Version: v4

Add-AssertionOperator

SYNOPSIS​

Register an Assertion Operator with Pester

SYNTAX​

Add-AssertionOperator [-Name] <String> [-Test] <ScriptBlock> [[-Alias] <String[]>] [[-InternalName] <String>]
 [-SupportsArrayInput] [<CommonParameters>]

DESCRIPTION​

This function allows you to create custom Should assertions.

EXAMPLES​

EXAMPLE 1​

function BeAwesome($ActualValue, [switch] $Negate)
{

    [bool] $succeeded = $ActualValue -eq 'Awesome'
    if ($Negate) { $succeeded = -not $succeeded }

    if (-not $succeeded)
    {
        if ($Negate)
        {
            $failureMessage = "{$ActualValue} is Awesome"
        }
        else
        {
            $failureMessage = "{$ActualValue} is not Awesome"
        }
    }

    return New-Object psobject -Property @{
        Succeeded      = $succeeded
        FailureMessage = $failureMessage
    }
}

Add-AssertionOperator -Name  BeAwesome `
                    -Test  $function:BeAwesome `
                    -Alias 'BA'

PS C:\> "bad" | should -BeAwesome
{bad} is not Awesome

PARAMETERS​

-Name​

The name of the assertion. This will become a Named Parameter of Should.

Type: String
Parameter Sets: (All)
Aliases:

Required: True
Position: 1
Default value: None
Accept pipeline input: False
Accept wildcard characters: False

-Test​

The test function. The function must return a PSObject with a [Bool]succeeded and a [string]failureMessage property.

Type: ScriptBlock
Parameter Sets: (All)
Aliases:

Required: True
Position: 2
Default value: None
Accept pipeline input: False
Accept wildcard characters: False

-Alias​

A list of aliases for the Named Parameter.

Type: String[]
Parameter Sets: (All)
Aliases:

Required: False
Position: 3
Default value: @()
Accept pipeline input: False
Accept wildcard characters: False

-InternalName​

If -Name is different from the actual function name, record the actual function name here. Used by Get-ShouldOperator to pull function help.

Type: String
Parameter Sets: (All)
Aliases:

Required: False
Position: 4
Default value: None
Accept pipeline input: False
Accept wildcard characters: False

-SupportsArrayInput​

Does the test function support the passing an array of values to test.

Type: SwitchParameter
Parameter Sets: (All)
Aliases:

Required: False
Position: Named
Default value: False
Accept pipeline input: False
Accept wildcard characters: False

CommonParameters​

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

INPUTS​

OUTPUTS​

NOTES​

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