Public/Find-FunctionCall.ps1
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function Find-FunctionCall { <# .SYNOPSIS For a given function, find what functions it calls. .DESCRIPTION For the purposes of working out dependencies, it may be good to know what a function depends on at the function scale. This command takes a function and builds a tree of functions called by that function. .PARAMETER Name Provide the name of a function to analyse. .PARAMETER Function Provide a function object as input. This will be the output of Get-Command. .PARAMETER Depth Maximum level of nesting to analyse. If this depth is exceeded, a warning will be emitted. .INPUTS [System.Management.Automation.FunctionInfo] .OUTPUTS [FunctionCallInfo] This command outputs an object similar to System.Management.Automation.FunctionInfo. Note that this is not a child class of FunctionInfo. .EXAMPLE 'Install-Module' | Get-Command | Find-FunctionCall CommandType Name Version Source ----------- ---- ------- ------ Function Install-Module PowerShellGet Function Get-ProviderName PowerShellGet Function Get-PSRepository PowerShellGet Function New-ModuleSourceFromPackageSource PowerShellGet Function Install-NuGetClientBinaries PowerShellGet Function Get-ParametersHashtable PowerShellGet Function Test-RunningAsElevated PowerShellGet Function ThrowError PowerShellGet Function New-PSGetItemInfo PowerShellGet Function Get-EntityName PowerShellGet Function Get-First PowerShellGet Function Get-SourceLocation PowerShellGet Function Set-ModuleSourcesVariable PowerShellGet Function DeSerialize-PSObject PowerShellGet Function Get-PublishLocation PowerShellGet Function Get-ScriptSourceLocation PowerShellGet For the 'Install-Module' command from the PowerShellGet module, determine the call tree. #> [OutputType([FunctionCallInfo[]])] [CmdletBinding(DefaultParameterSetName = 'FromFunction')] param ( [Parameter(ParameterSetName = 'ByName', Mandatory, ValueFromPipeline)] [string]$Name, [Parameter(ParameterSetName = 'FromFunction', Mandatory, ValueFromPipeline)] [Management.Automation.FunctionInfo]$Function, [Parameter()] [int]$Depth = 4, [Parameter(DontShow, ParameterSetName = 'Recursing', Mandatory, ValueFromPipeline)] [FunctionCallInfo]$CallingFunction, [Parameter(DontShow, ParameterSetName = 'Recursing')] [int]$_CallDepth = 0, [Parameter(DontShow, ParameterSetName = 'Recursing')] [Collections.Generic.HashSet[Management.Automation.FunctionInfo]]$_SeenFunctions = [Collections.Generic.HashSet[Management.Automation.FunctionInfo]]::new() ) process { if ($_CallDepth -ge $Depth) { Write-Warning "Resulting output is truncated as call tree has exceeded the set depth of $Depth." return } if ($PSCmdlet.ParameterSetName -eq 'ByName') { $Function = Get-Command $Name -CommandType Function -ErrorAction Stop } if ($PSCmdlet.ParameterSetName -eq 'Recursing') { $Function = $CallingFunction.Function } else { $CallingFunction = [FunctionCallInfo]$Function } # Returns false if already in set if (-not $_SeenFunctions.Add($Function)) { return } if (-not $_CallDepth) { $CallingFunction } $_CallDepth++ $Def = "function $($Function.Name) {$($Function.Definition)}" $Tokens = @() [void][Management.Automation.Language.Parser]::ParseInput($Def, [ref]$Tokens, [ref]$null) $CommandTokens = $Tokens | Where-Object {$_.TokenFlags -band 'CommandName'} $CalledCommandNames = $CommandTokens.Text | Sort-Object -Unique if (-not $CalledCommandNames) { return } $CalledCommands = if ($Function.Module) { & $Function.Module {$args | Get-Command} $CalledCommandNames } else { Get-Command $CalledCommandNames } [FunctionCallInfo[]]$CalledFunctions = $CalledCommands | Where-Object CommandType -eq 'Function' if (-not $CalledFunctions) { return } $CalledFunctions | ForEach-Object { $_.Depth = $_CallDepth $_.CalledBy = $CallingFunction # Recurse [FunctionCallInfo[]]$CallsOfCalls = $_ | Find-FunctionCall -Depth $Depth -_CallDepth $_CallDepth -_SeenFunctions $_SeenFunctions $_ | Write-Output if ($CallsOfCalls) { $_.Calls.AddRange($CallsOfCalls) $CallsOfCalls | Write-Output } } } } |