Functions/Private/Confirm-StringBuilderSubstring.ps1
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function Confirm-StringBuilderSubstring { <# .SYNOPSIS Confirms that the substring exists at the specified offset in the string builder. .DESCRIPTION Confirms that the substring exists at the specified offset in the string builder. An error will be thrown if the offset positions do not match expectation. .PARAMETER FileContents Specify the file contents wrapped in a stringbuilder. .PARAMETER Substring Specify the substring to validate. .PARAMETER StartOffset Specify the start offset position. .PARAMETER EndOffset Specify the end offset position. .EXAMPLE PS C:\ Confirm-StringBuilderSubstring -FileContent $builder -Substring '-test' -StartOffset 23 -EndOffset 28 Confirms that the substring '-test' exists at the specified offset. #> [CmdletBinding()] Param ( [Parameter( Mandatory=$true, HelpMessage='Specify the file contents wrapped in a stringbuilder.')] [System.Text.StringBuilder] [ValidateNotNull()] $FileContent, [Parameter( Mandatory=$true, HelpMessage='Specify the substring to validate.')] [System.String] [ValidateNotNullOrEmpty()] $Substring, [Parameter( Mandatory=$true, HelpMessage='Specify the start offset position.')] [System.String] [ValidateNotNullOrEmpty()] $StartOffset, [Parameter( Mandatory=$true, HelpMessage='Specify the end offset position.')] [System.String] [ValidateNotNullOrEmpty()] $EndOffset ) Process { if ($FileContent.Length -lt $StartOffset -or $FileContent.Length -lt $EndOffset) { throw 'Upgrade step failed: Offset positions are beyond the file range.' } for (([int]$i = $StartOffset), ([int]$j = 0); $i -lt $EndOffset; ($i++), ($j++)) { if ($FileContent[$i] -ne $Substring[$j]) { throw 'Upgrade step failed: Offset positions are unexpected. This file may have already been upgraded or has changed since the upgrade plan was generated.' } } } } |