Transpilers/Explicit.psx.ps1
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<# .Synopsis Makes Output from a PowerShell function Explicit. .Description Makes a PowerShell function explicitly output. All statements will be assigned to $null, unless they explicitly use Write-Output or echo. If Write-Output or echo is used, the command will be replaced for more effecient output. #> [OutputType([Collections.IDictionary])] param( [Parameter(Mandatory,ValueFromPipeline)] [ScriptBlock] $ScriptBlock ) process { $pipelines = $ScriptBlock.Ast.FindAll({ param($ast) $ast -is [System.Management.Automation.Language.PipelineAst] }, $false) $astReplacements = [Ordered]@{} foreach ($pipeline in $pipelines) { $pipelineParent = $pipeline.Parent $pipelineGrandParent = $pipeline.Parent.Parent if ($pipelineParent -is [Management.Automation.Language.CommandAst] -or $pipelineGrandParent -is [Management.Automation.Language.CommandAst]) { continue } if ($pipelineParent -is [Management.Automation.Language.AssignmentStatementAst] -or $pipelineGrandParent -is [Management.Automation.Language.AssignmentStatementAst]) { continue } if ($pipelineParent -is [Management.Automation.Language.ReturnStatementAst] -or $pipelineGrandParent -is [Management.Automation.Language.ReturnStatementAst] ) { continue } $nullify = $pipeline.PipelineElements[-1] -isnot [System.Management.Automation.Language.CommandAst] if (-not $nullify) { $cmdName = $pipeline.PipelineElements[-1].CommandElements[0].Value $isOutputCmdName = '^(?>Out|Write|Show|Format)' $resolvedAlias = $ExecutionContext.SessionState.InvokeCommand.GetCommand($cmdName, 'Alias') $nullify = $cmdName -notmatch $isOutputCmdName -and $resolvedAlias.Definition -notmatch $isOutputCmdName $isWriteOutput = $cmdName -in 'Write-Output', 'echo', 'write' if ($isWriteOutput) { if ($pipeline.PipelineElements.Count -gt 1) { $strPipeline = "$pipeline" # .PipelineElements[0..($pipeline.PipelineElements.Count - 2)] $restOfPipeline = $strPipeline.Substring(0, $strPipeline.Length - $pipeline.PipelineElements[-1].ToString().Length) $astReplacements[$pipeline] = [ScriptBlock]::Create($restOfPipeline.TrimEnd().TrimEnd('|')) } else { $ce = $pipeline.PipelineElements[0].CommandElements $astReplacements[$pipeline] = [ScriptBlock]::Create($ce[1..($ce.Count - 1)] -join ' ') } continue } } if ($nullify) { $astReplacements[$pipeline] = [ScriptBlock]::Create("`$null = $pipeline") } } $astReplacements # @{AstReplacement=$astReplacements} } |