Assert-​Mock​Called

Checks if a Mocked command has been called a certain number of times and throws an exception if it has not.

Syntax

Assert-MockCalled
      [-CommandName] <String>
      [[-Times] <Int32>]
      [[-ParameterFilter] <ScriptBlock>]
      [[-ModuleName] <String>]
      [[-Scope] <String>]
      [-Exactly]
Assert-MockCalled
      [-CommandName] <String>
      [[-Times] <Int32>]
      [[-ModuleName] <String>]
      [[-Scope] <String>]
      -ExclusiveFilter <ScriptBlock>
      [-Exactly]

Description

This command verifies that a mocked command has been called a certain number of times. If the call history of the mocked command does not match the parameters passed to Assert-MockCalled, Assert-MockCalled will throw an exception.

Examples

-------------------------- EXAMPLE 1 --------------------------

Mock Set-Content {}

{... Some Code ...}

C:\PS>Assert-MockCalled Set-Content

This will throw an exception and cause the test to fail if Set-Content is not called in Some Code.

-------------------------- EXAMPLE 2 --------------------------

Mock Set-Content -parameterFilter {$path.StartsWith("$env:temp\")}

{... Some Code ...}

C:\PS>Assert-MockCalled Set-Content 2 { $path -eq "$env:temp\test.txt" }

This will throw an exception if some code calls Set-Content on $path=$env:temp\test.txt less than 2 times

-------------------------- EXAMPLE 3 --------------------------

Mock Set-Content {}

{... Some Code ...}

C:\PS>Assert-MockCalled Set-Content 0

This will throw an exception if some code calls Set-Content at all

-------------------------- EXAMPLE 4 --------------------------

Mock Set-Content {}

{... Some Code ...}

C:\PS>Assert-MockCalled Set-Content -Exactly 2

This will throw an exception if some code does not call Set-Content Exactly two times.

-------------------------- EXAMPLE 5 --------------------------

Describe 'Assert-MockCalled Scope behavior' {

Mock Set-Content { }

It 'Calls Set-Content at least once in the It block' {
    {...

Some Code ...}

    Assert-MockCalled Set-Content -Exactly 0 -Scope It
}

}

Checks for calls only within the current It block.

-------------------------- EXAMPLE 6 --------------------------

Describe 'Describe' {

Mock -ModuleName SomeModule Set-Content { }

{...

Some Code ...}

It 'Calls Set-Content at least once in the Describe block' {
    Assert-MockCalled -ModuleName SomeModule Set-Content
}

}

Checks for calls to the mock within the SomeModule module. Note that both the Mock and Assert-MockCalled commands use the same module name.

-------------------------- EXAMPLE 7 --------------------------

Assert-MockCalled Get-ChildItem -ExclusiveFilter { $Path -eq 'C:\' }

Checks to make sure that Get-ChildItem was called at least one time with the -Path parameter set to 'C:\', and that it was not called at all with the -Path parameter set to any other value.

Required Parameters

-CommandName

The mocked command whose call history should be checked.

Type:String
Position:1
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-ExclusiveFilter

{{Fill ExclusiveFilter Description}}

Type:ScriptBlock
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False

Optional Parameters

-Exactly

If this switch is present, the number specified in Times must match exactly the number of times the mock has been called. Otherwise it must match "at least" the number of times specified. If the value passed to the Times parameter is zero, the Exactly switch is implied.

Type:SwitchParameter
Position:Named
Default value:False
Accept pipeline input:False
Accept wildcard characters:False
-ModuleName

The module where the mock being checked was injected. This is optional, and must match the ModuleName that was used when setting up the Mock.

Type:String
Position:4
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-ParameterFilter

An optional filter to qualify wich calls should be counted. Only those calls to the mock whose parameters cause this filter to return true will be counted.

Type:ScriptBlock
Position:3
Default value:{$True}
Accept pipeline input:False
Accept wildcard characters:False
-Scope

An optional parameter specifying the Pester scope in which to check for calls to the mocked command. By default, Assert-MockCalled will find all calls to the mocked command in the current Context block (if present), or the current Describe block (if there is no active Context.) Valid values are Describe, Context and It. If you use a scope of Describe or Context, the command will identify all calls to the mocked command in the current Describe / Context block, as well as all child scopes of that block.

Type:String
Position:5
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Times

The number of times that the mock must be called to avoid an exception from throwing.

Type:Int32
Position:2
Default value:1
Accept pipeline input:False
Accept wildcard characters:False

Notes

The parameter filter passed to Assert-MockCalled does not necessarily have to match the parameter filter (if any) which was used to create the Mock. Assert-MockCalled will find any entry in the command history which matches its parameter filter, regardless of how the Mock was created. However, if any calls to the mocked command are made which did not match any mock's parameter filter (resulting in the original command being executed instead of a mock), these calls to the original command are not tracked in the call history. In other words, Assert-MockCalled can only be used to check for calls to the mocked implementation, not to the original.