Private/Metrics/Measure-FunctionMaxNestingDepth.ps1
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Function Measure-FunctionMaxNestingDepth { <# .SYNOPSIS Gets the depth of the most deeply nested statement in the function. .DESCRIPTION Gets the depth of the most deeply nested statement in the function. Measuring the maximum nesting depth in a function is a way of evaluating its complexity. .PARAMETER FunctionDefinition To specify the function definition to analyze. .EXAMPLE PS C:\> Measure-FunctionMaxNestingDepth -FunctionDefinition $MyFunctionAst Gets the depth of the most deeply nested statement in the specified function definition. .OUTPUTS System.Int32 .LINK Additional information on why maximum nesting depth is an interesting measure of code complexity : https://www.cqse.eu/en/blog/mccabe-cyclomatic-complexity/ #> [CmdletBinding()] [OutputType([System.Int32])] Param ( [Parameter(Position=0, Mandatory)] [System.Management.Automation.Language.FunctionDefinitionAst]$FunctionDefinition ) $FunctionText = $FunctionDefinition.Extent.Text $Tokens = $Null $Null = [System.Management.Automation.Language.Parser]::ParseInput($FunctionText, [ref]$Tokens, [ref]$Null) [System.Collections.ArrayList]$NestingDepthValues = @() [System.Int32]$NestingDepth = 0 [System.Collections.ArrayList]$CurlyBraces = $Tokens.Where({ $_.Kind -in 'AtCurly','LCurly','RCurly' }) # Removing the first opening curly and the last closing curly because they belong to the function itself $CurlyBraces.RemoveAt(0) $CurlyBraces.RemoveAt(($CurlyBraces.Count - 1)) If ( -not $CurlyBraces ) { return $NestingDepth } Foreach ( $CurlyBrace in $CurlyBraces ) { If ( $CurlyBrace.Kind -in 'AtCurly','LCurly' ) { $NestingDepth++ } ElseIf ( $CurlyBrace.Kind -eq 'RCurly' ) { $NestingDepth-- } $Null = $NestingDepthValues.Add($NestingDepth) } Write-VerboseOutput -Message "Number of nesting depth values : $($NestingDepthValues.Count)" $MaxDepthValue = ($NestingDepthValues | Measure-Object -Maximum).Maximum -as [System.Int32] return $MaxDepthValue } |