Rule request: AvoidDefaultEncoding

まず PSUseCompatibleCommands ルールとその互換性プロファイルを確認し、次にリンクされている Windows PowerShell と PowerShell のエンコーディングに関するドキュメントを比較します。互換性分析が有効な場合の -Encoding Default と -Encoding utf8 に対する想定される診断を定義し、新しい値である Ansi と utf8NoBom をどのように扱うべきかも含めます。ルールの動作と対応するカバレッジがその決定を反映した時点で、issue は完了です。

Apparently the default encoding -Encoding Default is removed from the cmdlet documentation that supports the -Encoding parameter. See e.g.:

• https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.management/get-content?view=powershell-5.1
• https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.management/get-content?view=powershell-7.5

Which makes sense in a way that this might cause compatibility issues when something is e.g. written (using -Encoding Default in Windows PowerShell 5.1 and read back in PowerShell 7 (e.g. after a PowerShell update migration). Yet, afaik, this isn't captured by any of the UseCompatibleCommands profiles either (probably because the default value is still accepted.

Also note:

• that using any of the newer encoding values as Ansi and utf8NoBom in PowerShell 7 might cause an incompatibility issue with older versions of PowerShell.
• the implementation of the -Encoding utf8 value also differs between Windows PowerShell and newer versions of PowerShell:
  • Character encoding in Windows PowerShell: UTF8 Uses UTF-8 (with BOM).
  • Character encoding in PowerShell: utf8: Encodes in UTF-8 format (no BOM).

Therefore I think that it is wise to avoid the default and utf8 encoding (-Encoding Default and -Encoding utf8) when PSUseCompatibleCommands is enabled in the PSScriptAnalyzer settings.