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Code coverage fails in some circumstances when UseBreakpoints is `$false`
Checklist
- [X] Issue has a meaningful title
- [X] I have searched the existing issues. See all issues
- [X] I have tested using the latest version of Pester. See Installation and update guide.
What is the issue?
I started seening this issue when I started doing class-based resource ~1 year ago, and since it has been troublesome to make a repro case so I just switched to using breakpoints for code coverage instead. But now I managed to repro it with simpler code and simpler tests.
This test works when CodeCoverage.UseBreakpoints = $true but fails when CodeCoverage.UseBreakpoints = $false.
There seems to be a problem somewhere inside Pester when using this new code coverage method.
Expected Behavior
The tests to pass regardless if UseBreakpoints is set to $true or $false.
Steps To Reproduce
File SqlServerDsc.psm1
class StartupParameters
{
[System.UInt32[]]
$TraceFlag
static [StartupParameters] Parse([System.String] $InstanceStartupParameters)
{
$startupParameters = [StartupParameters]::new()
$startupParameterValues = $InstanceStartupParameters -split ';'
$startupParameters.TraceFlag = [System.UInt32[]] @(
$startupParameterValues |
Where-Object -FilterScript {
$_ -match '^-T\d+'
} |
ForEach-Object -Process {
[System.UInt32] $_.TrimStart('-T')
}
)
return $startupParameters
}
}
function Get-SqlDscTraceFlag
{
[OutputType([System.UInt32[]])]
[CmdletBinding(DefaultParameterSetName = 'ByServerName')]
param
(
[Parameter(ParameterSetName = 'ByServiceObject', Mandatory = $true)]
[Object]
$ServiceObject
)
$traceFlags = [System.UInt32[]] @()
if ($ServiceObject.StartupParameters)
{
$traceFlags = [StartupParameters]::Parse($ServiceObject.StartupParameters).TraceFlag
}
return , [System.UInt32[]] $traceFlags
}
File SqlServerDsc.Tests.ps1
BeforeAll {
Import-Module -Name './SqlServerDsc.psm1' -Force
}
AfterAll {
# Unload the module being tested so that it doesn't impact any other tests.
Get-Module -Name 'SqlServerDsc' -All | Remove-Module -Force
}
Describe 'SqlServerDsc' {
Context 'When one trace flag exist' {
BeforeAll {
$mockStartupParameters = '-T4199'
$mockServiceObject = [PSCustomObject] @{
StartupParameters = $mockStartupParameters
}
}
Context 'When passing a service object' {
It 'Should return the correct values' {
$result = Get-SqlDscTraceFlag -ServiceObject $mockServiceObject
$result | Should -HaveCount 1
$result | Should -Contain 4199
}
}
}
}
File debug.ps1
Switch UseBreakpoints to $true to verify that the tests passes using breakpoints for code coverage.
$pesterConfig = New-PesterConfiguration -Hashtable @{
CodeCoverage = @{
Enabled = $true
Path = './SqlServerDsc.psm1'
OutputPath = './Pester_coverage.xml'
# Tests fails if this is $false
UseBreakpoints = $false
}
Run = @{
Path = '*.Tests.ps1'
}
}
$Error.Clear()
$ErrorView = 'DetailedView'
Invoke-Pester -Configuration $pesterConfig
$Error
Describe your environment
Pester version : 5.4.0 C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1
PowerShell version : 7.3.2
OS version : Microsoft Windows NT 10.0.22623.0
Possible Solution?
Sorry, unknown.
Forgot to add the actual error.
Exception :
Type : System.ArgumentOutOfRangeException
Message : Index was out of range. Must be non-negative and less than or equal to the size of the collection. (Parameter 'index')
ParamName : index
TargetSite :
Name : Insert
DeclaringType : System.Text.StringBuilder
MemberType : Method
Module : System.Private.CoreLib.dll
Data : System.Collections.ListDictionaryInternal
Source : System.Private.CoreLib
HResult : -2146233086
StackTrace :
at System.Text.StringBuilder.Insert(Int32 index, String value)
at System.Management.Automation.Language.PositionUtilities.BriefMessage(IScriptPosition position)
at System.Management.Automation.ScriptDebugger.TraceLine(IScriptExtent extent)
at System.Management.Automation.ScriptDebugger.OnSequencePointHit(FunctionContext functionContext)
at System.Management.Automation.ScriptDebugger.EnterScriptFunction(FunctionContext functionContext)
at System.Management.Automation.Interpreter.ActionCallInstruction`2.Run(InterpretedFrame frame)
at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)
at System.Management.Automation.Interpreter.Interpreter.Run(InterpretedFrame frame)
at System.Management.Automation.Interpreter.LightLambda.RunVoid1[T0](T0 arg0)
at System.Management.Automation.ScriptBlock.InvokeWithPipeImpl(ScriptBlockClauseToInvoke clauseToInvoke, Boolean createLocalScope, Dictionary`2 functionsToDefine, List`1 variablesToDefine, ErrorHandlingBehavior errorHandlingBehavior, Object dollarUnder, Object input, Object scriptThis, Pipe outputPipe, InvocationInfo invocationInfo, Object[] args)
at System.Management.Automation.ScriptBlock.InvokeWithPipe(Boolean useLocalScope, ErrorHandlingBehavior errorHandlingBehavior, Object dollarUnder, Object input, Object scriptThis, Pipe outputPipe, InvocationInfo invocationInfo, Boolean propagateAllExceptionsToTop, List`1 variablesToDefine, Dictionary`2 functionsToDefine, Object[] args)
at System.Management.Automation.ScriptBlock.InvokeAsMemberFunction(Object instance, Object[] args)
at System.Management.Automation.Internal.ScriptBlockMemberMethodWrapper.InvokeHelper(Object instance, Object sessionStateInternal, Object[] args)
at CallSite.Target(Closure, CallSite, Type)
at System.Management.Automation.Interpreter.DynamicInstruction`2.Run(InterpretedFrame frame)
at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)
CategoryInfo : OperationStopped: (:) [], ArgumentOutOfRangeException
FullyQualifiedErrorId : System.ArgumentOutOfRangeException
InvocationInfo :
ScriptLineNumber : 9
OffsetInLine : 9
HistoryId : -1
ScriptName : C:\source\DebugCodeCoverage\SqlServerDsc.psm1
Line : $startupParameters = [StartupParameters]::new()
PositionMessage : At C:\source\DebugCodeCoverage\SqlServerDsc.psm1:9 char:9
+ $startupParameters = [StartupParameters]::new()
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PSScriptRoot : C:\source\DebugCodeCoverage
PSCommandPath : C:\source\DebugCodeCoverage\SqlServerDsc.psm1
CommandOrigin : Internal
ScriptStackTrace : at Parse, C:\source\DebugCodeCoverage\SqlServerDsc.psm1: line 9
at Get-SqlDscTraceFlag, C:\source\DebugCodeCoverage\SqlServerDsc.psm1: line 45
at <ScriptBlock>, C:\source\DebugCodeCoverage\SqlServerDsc.Tests.ps1: line 22
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1998
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1959
at Invoke-ScriptBlock, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 2120
at Invoke-TestItem, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1194
at Invoke-Block, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 830
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 888
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1998
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1959
at Invoke-ScriptBlock, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 2123
at Invoke-Block, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 935
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 888
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1998
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1959
at Invoke-ScriptBlock, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 2123
at Invoke-Block, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 935
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 888
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1998
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1959
at Invoke-ScriptBlock, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 2123
at Invoke-Block, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 935
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 888
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1998
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1959
at Invoke-ScriptBlock, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 2123
at Invoke-Block, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 935
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1672
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.ps1: line 3
at <ScriptBlock>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 3164
at Invoke-InNewScriptScope, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 3171
at Run-Test, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 1675
at Invoke-Test, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 2475
at Invoke-Pester<End>, C:\source\SqlServerDsc\output\RequiredModules\Pester\5.4.0\Pester.psm1: line 5272
at <ScriptBlock>, C:\source\DebugCodeCoverage\debug.ps1: line 17
at <ScriptBlock>, <No file>: line 1
Thanks for the report. This is a weird one. Can reproduce, but have no idea what's going on. Will probably need to debug pwsh, so leaving it to our CC-wizard 🧙♂️
This is also a PowerShell-bug. The invoked code isn't modified by us at all. Our injected code gets triggered right after this actually.
Repro:
class MyClass {
# Any method has to exist, regardless of scriptblock, parameters or static/non-static
MyMethod() { }
}
Set-PSDebug -Trace 1
[MyClass]::new()
Found this issue when I went to report it: https://github.com/PowerShell/PowerShell/issues/16874
@johlju: I found a workaround for now. Add a constructor to the class, ex. StartupParameters() { }
Thank you for putting the work in, and also finding a workaround for this! It seems to work perfectly. I have re-enabled Pester's new code coverage method in the pipeline for SqlServerDsc.