[ENHANCEMENT] Add support for .al (AL Language) file extension with fallback chunking

[yavpungggi]

Problem (one or two sentences)

Users working with AL Language files (Microsoft Dynamics 365 Business Central) cannot use Roo Code's codebase indexing and context features because .al files are not recognized as supported file extensions. Currently, file extensions are hardcoded in the source code with no configuration option for users to add custom extensions.

Context (who is affected and when)

Developers working on Microsoft Dynamics 365 Business Central projects using AL Language encounter this limitation whenever they try to use Roo Code's AI-powered features like codebase search, code indexing, or context-aware assistance. This affects them throughout their entire development workflow when working with .al files.

Desired behavior (conceptual, not technical)

When users open or work with .al files in their workspace, Roo Code should recognize these files and include them in codebase indexing, search, and context operations. The files should be processed using simple length-based chunking (since no dedicated AL language parser exists) rather than being ignored entirely.

Constraints / preferences (optional)

• Performance: Use fallback chunking mechanism (length-based) instead of tree-sitter parsing since no WASM parser exists for AL Language
• Maintainability: Follow the existing pattern established for other languages without dedicated parsers (e.g., Visual Basic .NET, Scala, Swift)
• Consistency: Maintain the same code organization and documentation standards used for other supported extensions
• No breaking changes: This is purely additive and should not affect existing functionality

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)

Given a workspace containing .al files
When the user opens Roo Code and performs codebase operations
Then .al files should be:

• Recognized as supported file extensions
• Included in codebase scanning and indexing
• Processed using fallback chunking (not tree-sitter parsing)
• Searchable through codebase retrieval features
• Available in context for AI assistance

Proposed approach (optional)

Following the documented process in src/services/code-index/shared/supported-extensions.ts:

1. Add "al" to the extensions array in src/services/tree-sitter/index.ts (line ~93)

• This registers .al as a recognized file extension

2. Add ".al" to the fallbackExtensions array in src/services/code-index/shared/supported-extensions.ts (line ~21-25)

• This tells the parser to use simple length-based chunking instead of tree-sitter parsing
• Include a comment: ".al", // AL Language (Dynamics 365 Business Central) - no dedicated WASM parser

3. Rebuild and test the extension to ensure:

• .al files are recognized
• Fallback chunking works correctly
• No regressions in existing functionality

Trade-offs / risks (optional)

No response

[roomote]

I'm exploring a potential fix for adding .al file extension support with fallback chunking. I'll open a PR to share progress.

[yavpungggi]

Claiming

[roomote]

Opened PR #8597 with my attempt at addressing this issue. The implementation adds support for .al file extensions with fallback chunking as requested. CI checks are currently running. Feedback welcome!