GeezerVison

PR Summary

This PR adds a new rule PSUseConstrainedLanguageMode that identifies PowerShell patterns incompatible with Constrained Language Mode, helping developers ensure scripts work in restricted environments. This rule is a Warning, but is optional and not enabled by default.

New files:
Rules/UseConstrainedLanguageMode.cs - Implements 14 CLM restriction checks
Tests/Rules/UseConstrainedLanguageMode.tests.ps1 - Adds 46 comprehensive tests
docs/Rules/UseConstrainedLanguageMode.md - Provides complete user documentation

Modified files;

Rules/strings.resx - Adds 16 new diagnostic message strings

Features
Detects CLM Violations:

• Add-Type usage (code compilation)
• Disallowed COM objects (only allows Scripting.Dictionary, Scripting.FileSystemObject, VBScript.RegExp)
• Disallowed .NET types (validates ~70 allowed types including primitives, collections, PowerShell types)
• PowerShell classes (class keyword)
• XAML/WPF usage
• Invoke-Expression usage
• Dot-sourcing patterns
• Type constraints, expressions, and casts
• Member invocations on disallowed types
• Module manifest wildcards and .ps1 references

Signature Awareness:

• Detects signature blocks (# SIG # Begin signature block)
• Applies selective checking to signed scripts (dot-sourcing, parameter types, manifests only)
• Applies full checking to unsigned scripts

Array Type Support:

• Handles array notation correctly ([string[]], [int[][]])
• Strips brackets and validates base types

Configuration:

• IgnoreSignatures property (default: false) bypasses signature detection and enforces full CLM compliance for all scripts

Testing:

PR Checklist

• PR has a meaningful title
  • Use the present tense and imperative mood when describing your changes
• Summarized changes
• Change is not breaking
• Make sure all .cs, .ps1 and .psm1 files have the correct copyright header
• Make sure you've added a new test if existing tests do not effectively test the code changed and/or updated documentation
• This PR is ready to merge and is not Work in Progress.
  • If the PR is work in progress, please add the prefix WIP: to the beginning of the title and remove the prefix when the PR is ready.