PowerShell.MCP v1.2.8 - Quality & Encoding Enhancement

[yotsuda]

Quality & Encoding Enhancement

This release fixes the v1.2.7 performance regression, adds automatic console startup, extends automatic encoding upgrade to all cmdlets, adds comprehensive encoding aliases, and establishes a complete test suite.

✨ What's New

🔧 Performance Fix

Fixed v1.2.7 performance regression:

• File metadata detection is now 19-22x faster through partial reading
• Restores performance to pre-v1.2.7 levels

⚡ Automatic PowerShell Console Start

get_current_location and invoke_expression now automatically start the PowerShell console if not running:

• get_current_location: Starts console and returns location
• invoke_expression: Starts console but skips execution (AI verifies location first)

If console is already running, both tools execute immediately.

🔄 Automatic Encoding Upgrade - Now Complete

Automatic ASCII to UTF-8 encoding upgrade, previously available in Add-LinesToFile and Update-LinesToFile (v1.2.7), is now also supported in Update-MatchInFile:

# Start with ASCII file
"Server=localhost" | Set-Content config.txt -Encoding ASCII

# Replace with non-ASCII - automatically upgrades to UTF-8
Update-MatchInFile config.txt -Pattern 'localhost' -Replacement '日本サーバー'
# ℹ Info: Content contains non-ASCII characters. Upgrading encoding to UTF-8.

All text file cmdlets now support automatic encoding upgrade when adding non-ASCII content.

🌍 Comprehensive Encoding Aliases

Added 100+ encoding aliases for better compatibility:

New Aliases:

• East Asian: cp932 (Shift-JIS), cp936 (GB2312), cp949 (EUC-KR), cp950 (Big5)
• BOM-explicit: utf8-sig, utf16-sig, utf32-sig (Python-standard)
• Regional: sjis, shift-jis, gbk, euc-kr, windows-1252, and many more

# All these work now
Show-TextFile file.txt -Encoding sjis
Show-TextFile file.txt -Encoding cp932
Show-TextFile file.txt -Encoding utf8-sig

📊 Comprehensive Test Coverage

Established complete test suite:

• 268 tests with 100% pass rate
• 87 unit tests (C#/xUnit) - 100% method coverage
• 169 integration tests (PowerShell/Pester)
• Covers all cmdlets, encodings, edge cases, and error handling

🔧 Code Quality Improvements

Major refactoring for maintainability:

• -35.2% code reduction (614 → 398 lines in TextFileUtility)
• Extracted specialized helpers: EncodingHelper, FileMetadataHelper, FileOperationHelper
• Fixed resource leaks
• Improved error handling

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🔄 Installation & Upgrade

# New installation
Install-Module PowerShell.MCP -Force

# Upgrade existing
Update-Module PowerShell.MCP

Update MCP Configuration

1. Get new module path:

(Get-Module PowerShell.MCP).ModuleBase

2. Update claude_desktop_config.json:

{
  "mcpServers": {
    "PowerShell": {
      "command": "C:\\Path\\To\\PowerShell.MCP\\1.2.8\\bin\\PowerShell.MCP.Proxy.exe"
    }
  }
}

3. Restart Claude Desktop

📖 Full Guide: https://github.com/yotsuda/PowerShell.MCP#quick-start

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💡 Usage Examples

Extended Encoding Aliases

# Japanese Shift-JIS - multiple aliases supported
Show-TextFile legacy.txt -Encoding sjis
Show-TextFile legacy.txt -Encoding cp932
Show-TextFile legacy.txt -Encoding shift-jis

# Python-standard BOM handling
Show-TextFile data.csv -Encoding utf8-sig

# Chinese encodings
Show-TextFile chinese.txt -Encoding gbk
Show-TextFile chinese.txt -Encoding cp936

Automatic Encoding Upgrade (All Cmdlets)

# Add-LinesToFile / Update-LinesInFile (v1.2.7~)
"Settings:" | Set-Content config.txt -Encoding ASCII
Add-LinesToFile config.txt -Content "名前: テスト"

# Update-MatchInFile (NEW in v1.2.8)
"Server=localhost" | Set-Content server.txt -Encoding ASCII
Update-MatchInFile server.txt -Pattern 'localhost' -Replacement '日本サーバー'

# All automatically upgrade to UTF-8 when needed

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📊 What's Changed Since v1.2.7

Fixed

• ✅ Performance regression in file metadata detection (19-22x faster)
• ✅ Resource leaks in start_powershell_console
• ✅ Various test failures and edge cases

Added

• ✅ Automatic encoding upgrade in Update-MatchInFile
• ✅ 100+ encoding aliases (East Asian, BOM-explicit, regional)
• ✅ Comprehensive test suite (268 tests, 100% pass rate)
• ✅ Automatic console start in get_current_location and invoke_expression
• ✅ Always show file path in Show-TextFile output

Improved

• ✅ Code maintainability (-35.2% code reduction)
• ✅ Error handling and messages
• ✅ Pipeline performance with lazy evaluation
• ✅ Resource management

Breaking Changes

• ❌ None - Full backward compatibility maintained

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🎯 Quality Assurance

• 268 tests with 100% pass rate
• 87 unit tests (C#/xUnit)
• 169 integration tests (PowerShell/Pester)
• ~87% code coverage
• All cmdlets, encodings, edge cases, and error handling validated

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📚 Resources

• Repository: https://github.com/yotsuda/PowerShell.MCP
• Questions? GitHub Discussions
• Report Issues: GitHub Issues

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⚠ Security Notice

PowerShell.MCP provides complete PowerShell access to Claude Desktop. Use only in trusted environments.

Best Practices:

• Review commands before execution
• Use -WhatIf for testing
• Enable -Backup for important files

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Full Changelog: v1.2.7...v1.2.8

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This discussion was created from the release PowerShell.MCP v1.2.8 - Quality & Encoding Enhancement.