[ENHANCEMENT] Inline terminal rendering parity with VSCode Terminal on Windows

[jerrill-johnson-bitwerx]

Problem (one or two sentences)

The inline terminal doesn't have functional parity with the VSCode terminal on Windows when rendering ANSI escape sequences, Unicode, or extended ASCII characters. I've provided my PowerShell test script (zipped) to reproduce the test.

terminal_test.zip

Context (who is affected and when)

Windows users of VSCode trying to migrate to using the inline terminal in Roo Code

Desired behavior (conceptual, not technical)

I've provided screenshots with the desired output (left side of image showing VSCode terminal) and actual output (right side of image showing Roo Code inline terminal).

Constraints / preferences (optional)

No response

Request checklist

• I've searched existing Issues and Discussions for duplicates
• This describes a specific problem with clear context and impact

Roo Code Task Links (optional)

No response

Acceptance criteria (optional)

No response

Proposed approach (optional)

No response

Trade-offs / risks (optional)

No response

[roomote]

I've analyzed this issue and here's my proposed implementation plan:

Root Cause Analysis

The inline terminal lacks ANSI rendering parity with VSCode's terminal due to two main issues:

1. Backend ANSI Stripping: In src/integrations/terminal/TerminalProcess.ts, the removeEscapeSequences method uses stripAnsi to remove ALL ANSI escape codes from terminal output before sending it to the webview. This intentionally removes colors, formatting, and cursor control sequences.

2. Frontend Plain Text Rendering: The CommandExecution.tsx component displays terminal output using a CodeBlock component with Shiki syntax highlighting (language="log"), which has no ANSI escape sequence rendering capability.

Proposed Implementation Plan

1. Backend Changes (TerminalProcess.ts)

• Modify removeEscapeSequences to only strip VSCode-specific shell integration markers (OSC 633/133) while preserving standard ANSI escape sequences for colors/formatting
• Keep stripping cursor movement and other control sequences that would cause display issues in the webview

2. Frontend Changes

• Add an ANSI-to-HTML library (e.g., ansi-to-html or ansi-to-react) to the webview-ui dependencies
• Create a new TerminalOutput component that:
  • Converts ANSI escape sequences to styled HTML/React elements
  • Uses a monospace font that supports Unicode and extended ASCII characters
  • Applies VSCode terminal color theme variables for consistent styling
• Update CommandExecution.tsx to use the new TerminalOutput component instead of CodeBlock for command output

3. Unicode/Extended ASCII Support

• Ensure the terminal output component uses a font that supports Unicode and box-drawing characters (e.g., inherit from --vscode-editor-font-family)
• Set proper text encoding/rendering attributes

Trade-offs

• Bundle Size: Adding an ANSI rendering library will slightly increase the webview bundle size (~10-20KB)
• Performance: ANSI parsing adds minimal overhead but is necessary for proper rendering
• Complexity: Introduces a new component but provides better separation of concerns between code blocks and terminal output

Please mention @roomote in a comment saying that you approve this plan, and I'll proceed with the implementation.