Warn on Undeclared Variable

There is currently a rule that warns when I have assigned a variable but haven't called it (UseDeclaredVarsMoreThanAssignments), however, there doesn't appear to be a rule that warns me if I have used a variable that hasn't been assigned.

Is this a possibility? I can definitely see there would be some challenges around implementing it correctly, but this would be a useful warning.

先閱讀現有的 UseDeclaredVarsMoreThanAssignments 規則及其周圍的 PSScriptAnalyzer 規則實作，以了解變數使用方式的分析方式。確定應如何處理在指派前使用的變數，接著定義涵蓋受支援情況的測試。當分析器回報未宣告變數的使用，且不會錯誤標記有效的指令碼時，即表示完成。