Describe

SYNOPSIS

Creates a logical group of tests.

SYNTAX

Describe [-Name] <String> [-Tag <String[]>] [[-Fixture] <ScriptBlock>] [<CommonParameters>]

DESCRIPTION

Creates a logical group of tests. All Mocks, TestDrive and TestRegistry contents defined within a Describe block are scoped to that Describe; they will no longer be present when the Describe block exits. A Describe block may contain any number of Context and It blocks.

EXAMPLES

EXAMPLE 1

function Add-Numbers($a, $b) {
return $a + $b
}
Describe "Add-Numbers" {
It "adds positive numbers" {
$sum = Add-Numbers 2 3
$sum | Should -Be 5
}
It "adds negative numbers" {
$sum = Add-Numbers (-2) (-2)
$sum | Should -Be (-4)
}
It "adds one negative number to positive number" {
$sum = Add-Numbers (-2) 2
$sum | Should -Be 0
}
It "concatenates strings if given strings" {
$sum = Add-Numbers two three
$sum | Should -Be "twothree"
}
}

PARAMETERS

-Name

The name of the test group. This is often an expressive phrase describing the scenario being tested.

Type: String
Parameter Sets: (All)
Aliases:
Required: True
Position: 1
Default value: None
Accept pipeline input: False
Accept wildcard characters: False

-Tag

Optional parameter containing an array of strings. When calling Invoke-Pester, it is possible to specify a -Tag parameter which will only execute Describe blocks containing the same Tag.

Type: String[]
Parameter Sets: (All)
Aliases: Tags
Required: False
Position: Named
Default value: @()
Accept pipeline input: False
Accept wildcard characters: False

-Fixture

The actual test script. If you are following the AAA pattern (Arrange-Act-Assert), this typically holds the arrange and act sections. The Asserts will also lie in this block but are typically nested each in its own It block. Assertions are typically performed by the Should command within the It blocks.

Type: ScriptBlock
Parameter Sets: (All)
Aliases:
Required: False
Position: 2
Default value: None
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

RELATED LINKS

https://pester.dev/docs/commands/It

https://pester.dev/docs/commands/Context

https://pester.dev/docs/commands/Invoke-Pester

https://pester.dev/docs/commands/Should

https://pester.dev/docs/usage/mocking

https://pester.dev/docs/usage/testdrive