public/Use-gThen.ps1
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function Use-gThen { <# .SYNOPSIS Extend a successful Promise. .DESCRIPTION The Use-gThen cmdlet starts a PowerShell background job on the local computer. It executes the ScriptBlock only if the specified Promise finished sucessfully. .EXAMPLE PS C:\> Start-gPromise { Write-Host 'hello' } | Use-gThen { Write-Host 'world' } hello world PS C:\> Start-gPromise { Write-Host 'hello'; throw } | Use-gThen { Write-Host 'world' } hello .EXAMPLE PS C:\> Start-gPromise { return 1, 2, 3 } | Use-gThen { param($a, $b, $c) Write-Host "$a;$b;$c" } 1;2;3 .INPUTS PSGoodies.PromiseGoodies.Model.Promise .OUTPUTS PSGoodies.PromiseGoodies.Model.Promise .NOTES https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise/then #> [CmdletBinding(DefaultParameterSetName = 'Pipeline')] [Alias('Use-Then', 'Then', 'gThen')] [OutputType([PSGoodies.PromiseGoodies.Model.Promise])] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true, ParameterSetName = 'Pipeline')] [Parameter(Mandatory = $true, Position = 1, ParameterSetName = 'Position')] [PSGoodies.PromiseGoodies.Model.Promise] $Promise, [Parameter(Mandatory = $true, Position = 0, ParameterSetName = 'Pipeline')] [Parameter(Mandatory = $true, Position = 0, ParameterSetName = 'Position')] [scriptblock] $ScriptBlock ) begin { # Load user defined commands $commandEntries = $ScriptBlock | Get-gCommandEntry # Load $using:* values $usings = $ScriptBlock | Get-gUsing -ParentPSCmdlet $PSCmdlet } process { $parentScriptBlock = { param($Promise, [ref] $ShouldSkip) $Promise | Wait-Job | Out-Null if ($Promise.Error.Count -gt 0) { $ShouldSkip.Value = $true $Promise.Error.ReadAll() | Write-Error } if ($Promise.State -eq 'Failed') { $ShouldSkip.Value = $true if ($Promise.JobStateInfo.Reason.WasThrownFromThrowStatement) { throw "Exception: $($Promise.JobStateInfo.Reason.ErrorRecord.ToString())" } $Promise.JobStateInfo.Reason.ErrorRecord | Write-Error } if ($ShouldSkip.Value) { return } $output = $Promise.Output.ReadAll() return $output } $jointScriptBlock = Join-gScriptBlock $parentScriptBlock $ScriptBlock $jointScriptBlock | Start-gInternalPromise -CommandEntries $commandEntries -Usings $usings -ArgumentList $Promise -ChildPromise $Promise } } |