Zauberwald/.planning/quick/260329-ton-markdown-in-companion-texten-zu-html-ren/260329-ton-SUMMARY.md

phase, plan, subsystem, tags, dependency_graph, tech_stack, key_files, decisions, metrics

phase	plan	subsystem	tags	dependency_graph	tech_stack	key_files	decisions	metrics
quick	260329-ton	utils/companion-ui	markdown rendering xss companion-texts	requires provides affects renderInlineMarkdown utility src/app.ts src/ui/screens.ts src/forest/reward.ts	added patterns inline-markdown-rendering XSS-safe innerHTML	created modified src/utils/markdown.ts src/utils/markdown.test.ts src/app.ts src/ui/screens.ts src/forest/reward.ts	Bold must be processed before italic so ** is not consumed as two separate * HTML escaping happens before markdown processing (prevents XSS injection) Italic regex requires non-space characters at asterisk boundaries to avoid false positives on math-like expressions	duration completed tasks_completed files_changed ~5 minutes 2026-03-29 2 5

Quick Task 260329-ton: Markdown in Companion Texts Summary

One-liner: Safe inline markdown renderer (renderInlineMarkdown) wired to all 3 AI-generated text insertion points so italic and bold display as styled HTML instead of raw asterisks.

Tasks Completed

#	Task	Commit	Files
1	Create renderInlineMarkdown utility with tests (TDD)	e10bdf8	src/utils/markdown.ts, src/utils/markdown.test.ts
2	Replace .textContent with .innerHTML + renderInlineMarkdown at all AI-text insertion points	d038cc3	src/app.ts, src/ui/screens.ts, src/forest/reward.ts

What Was Built

A renderInlineMarkdown(text: string): string pure utility function that:

1. Escapes HTML special characters (& < > " ') first to prevent XSS
2. Converts **bold** to <strong>bold</strong>
3. Converts *italic* to <em>italic</em>
4. Leaves standalone asterisks surrounded by spaces untouched

Used via innerHTML = renderInlineMarkdown(text) at:

• /src/app.ts line 228: greeting text from getGreeting()
• /src/ui/screens.ts line 423: letter intro text from getLetterIntro()
• /src/forest/reward.ts line 208: forest comment from getForestComment()

Verification

• npx vitest run — 92 tests pass (7 new markdown tests + 85 existing)
• npx tsc --noEmit — no type errors
• grep renderInlineMarkdown — exactly 3 usage sites (plus imports) across the 3 target files

Decisions Made

1. Bold before italic in processing order — ** must be matched before * so double-asterisk isn't consumed as two single asterisks first.
2. HTML escape before markdown — ensures any <, > in AI-generated text is neutralized before regex transforms it to valid HTML. No injection risk even if Gemini outputs HTML tags.
3. Italic regex boundary rule — pattern /\*(\S[^*]*?\S|\S)\*/g requires non-whitespace at the asterisk boundary, preventing 2 * 3 * 4 from becoming 2 <em>3</em> 4.

Deviations from Plan

None — plan executed exactly as written.

Known Stubs

None.

Self-Check: PASSED

Files created:

• /home/dev/workspace/zauberwald/src/utils/markdown.ts — FOUND
• /home/dev/workspace/zauberwald/src/utils/markdown.test.ts — FOUND

Commits:

• 860d671 (test RED)
• e10bdf8 (feat GREEN)
• d038cc3 (feat wiring)