White text in fenced code blocks: missing parser aliases (sh, yml, py, jsonc) cause fallback to hardcoded #ffffff

[gpid007]

Bug

Fenced code blocks using common language aliases like ```sh, ```yml, ```py, ```jsonc render as pure white text (#ffffff), making them illegible.

Root Cause

Two issues combine to produce this:

1. Missing language alias mappings in parsers-config.ts

The bash parser is registered as "bash", but when markdown content uses ```sh, the system looks for a parser named "sh" — which doesn't exist. Same for yml (registered as yaml), py (registered as python), and jsonc (registered as json).

The built-in infoStringMap in @opentui/core only maps js→javascript, ts→typescript, md→markdown. There are no aliases for sh→bash, yml→yaml, py→python, etc.

2. Hardcoded white fallback in @opentui/core

When the parser lookup fails, CodeRenderable falls back to plain text rendering using _defaultFg = RGBA(1, 1, 1, 1) (pure white #ffffff). The MarkdownRenderable.createCodeRenderable method does not pass a fg prop, so the theme's text color is never used as a fallback.

This only affects the <markdown> rendering path (experimental markdown / OPENCODE_EXPERIMENTAL_MARKDOWN). The <code filetype="markdown"> path is not affected because it uses tree-sitter's markup.raw.block scope.

Suggested Fix

Quick fix (opencode side): Add parser aliases in parsers-config.ts

Register duplicate entries pointing to the same wasm/queries:

Alias	Points to	Rationale
sh	bash	Most common shell alias
shell	bash	Common alias
zsh	bash	Close enough for highlighting
py	python	Common shorthand
jsonc	json	Used in many config files
yml	yaml	Very common alias

Proper fix (opentui side): Two changes

1. Pass theme foreground to child code renderables — In MarkdownRenderable.createCodeRenderable, pass the default syntax style foreground as the fg option so the fallback is theme.text instead of hardcoded white.

2. Expand infoStringMap — Add common language aliases so the parser lookup succeeds for standard markdown code fence tags.

Reproduction

1. Use any theme (solarized, opencode, gruvbox, etc.)
2. Have the assistant respond with a ```sh fenced code block
3. The code block content renders as white text

Environment

• OpenCode v1.2.10
• WSL2 (Ubuntu) with Windows Terminal
• Any theme — the white fallback bypasses all theme colors

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• Light themes: fenced code blocks can ignore theme colors and render with hardcoded white foreground #16508: Light themes: fenced code blocks can ignore theme colors and render with hardcoded white foreground
• Code blocks render with white text on light backgrounds #16731: Code blocks render with white text on light backgrounds
• Regression: fenced code blocks render with white text on light backgrounds (v1.2.24) #16978: Regression: fenced code blocks render with white text on light backgrounds

These issues describe the same root cause (hardcoded #ffffff fallback in CodeRenderable). If your issue is specifically about missing parser aliases (e.g. sh, yml, py, jsonc) causing the fallback rather than the fallback itself, please clarify that distinction so we can track it separately.

[kommander]

Should be fixed in the latest version.