Test/Pester.3.3.8/tools/Functions/Assertions/Should.ps1
function Parse-ShouldArgs([array] $shouldArgs) { if ($null -eq $shouldArgs) { $shouldArgs = @() } $parsedArgs = @{ PositiveAssertion = $true ExpectedValue = $null } $assertionMethodIndex = 0 $expectedValueIndex = 1 if ($shouldArgs.Count -gt 0 -and $shouldArgs[0].ToLower() -eq "not") { $parsedArgs.PositiveAssertion = $false $assertionMethodIndex += 1 $expectedValueIndex += 1 } if ($assertionMethodIndex -lt $shouldArgs.Count) { $parsedArgs.AssertionMethod = "Pester$($shouldArgs[$assertionMethodIndex])" } else { throw 'You cannot call Should without specifying an assertion method.' } if ($expectedValueIndex -lt $shouldArgs.Count) { $parsedArgs.ExpectedValue = $shouldArgs[$expectedValueIndex] } return $parsedArgs } function Get-TestResult($shouldArgs, $value) { $assertionMethod = $shouldArgs.AssertionMethod $command = Get-Command $assertionMethod -ErrorAction $script:IgnoreErrorPreference if ($null -eq $command) { $assertionMethod = $assertionMethod -replace '^Pester' throw "'$assertionMethod' is not a valid Should operator." } $testResult = (& $assertionMethod $value $shouldArgs.ExpectedValue) if ($shouldArgs.PositiveAssertion) { return -not $testResult } return $testResult } function Get-FailureMessage($shouldArgs, $value) { $failureMessageFunction = "$($shouldArgs.AssertionMethod)FailureMessage" if (-not $shouldArgs.PositiveAssertion) { $failureMessageFunction = "Not$failureMessageFunction" } return (& $failureMessageFunction $value $shouldArgs.ExpectedValue) } function New-ShouldErrorRecord ([string] $Message, [string] $Line, [string] $LineText) { $exception = New-Object Exception $Message $errorID = 'PesterAssertionFailed' $errorCategory = [Management.Automation.ErrorCategory]::InvalidResult # we use ErrorRecord.TargetObject to pass structured information about the error to a reporting system. $targetObject = @{Message = $Message; Line = $Line; LineText = $LineText} $errorRecord = New-Object Management.Automation.ErrorRecord $exception, $errorID, $errorCategory, $targetObject return $errorRecord } function Should { begin { Assert-DescribeInProgress -CommandName Should $parsedArgs = Parse-ShouldArgs $args } end { $input.MoveNext() do { $value = $input.Current $testFailed = Get-TestResult $parsedArgs $value if ($testFailed) { $lineText = $MyInvocation.Line.TrimEnd("`n") $line = $MyInvocation.ScriptLineNumber $failureMessage = Get-FailureMessage $parsedArgs $value throw ( New-ShouldErrorRecord -Message $failureMessage -Line $line -LineText $lineText) } } until ($input.MoveNext() -eq $false) } } |