Fix imported LaTeX currency notation

Author: Edwin Chan

CENTRAL.md

@@ -38,6 +38,7 @@ Stack: Next.js, NextAuth (Google + dev bypass), Prisma, KaTeX for math, Lucide i
 - **Mobile sidebar focus fix** — mobile sidebar sheet geometry now remains stable under `:hover`, `:focus`, and `:focus-within`, preventing the nav grid from jumping upward when a mobile tap focuses one of the upper links (source: `app/globals.css`).
 - **Answer previews and LaTeX grading** — Practice and problem-set answer boxes now render a small KaTeX preview above the input using `mathInputToTex(...)`. `lib/grading.ts` normalizes math delimiters and common LaTeX forms through `lib/math-input.ts`, so expression answers and answer keys can use `$...$`, `\sqrt{...}`, coefficients before functions like `5\sqrt{2}-7`, `\frac{...}{...}`, braced powers, and `\pi`.
 - **Expanded LaTeX statement support** — KaTeX is upgraded to `0.17.x`, the official `mhchem` extension enables `\ce{...}`, and `lib/latex-compat.ts` converts document wrappers plus `tabular`, `tabular*`, `tabularx`, and `longtable` into safe KaTeX-compatible arrays. Bare display environments render when mixed with prose. Rendering keeps `trust: false`, `maxSize: 50`, and `maxExpand: 1000`; full TeX document compilation and resource-loading commands remain unsupported. See `docs/latex-support.md`.
+- **Legacy LaTeX currency compatibility** — imported contest statements using full-LaTeX `\textdollar` or invalid currency sequences such as `\54` now render through bounded aliases in `lib/latex-compat.ts`; escaped row breaks remain unchanged.
 - **Anime.js animation pass** — the shared `MathCurveLoader` now drives SVG path drawing, rotation, and dot pulses with Anime.js v4 instead of CSS keyframes, `AnimeRouteEffects` adds reduced-motion-aware route reveal animations for key panels/rows/actions, and analytics surfaces use `AnalyticsMotion` plus animated `TrendChart` path/dots for growing bars and drawn charts. `TypewriterGreeting` keeps the existing typed/deleted text state machine and only animates the caret, avoiding per-character text tween flicker. Dependency: `animejs` in `package.json`.
 - **Per-set analytics access** — admins can open `/admin/sets/[id]/analytics` directly from the student-facing problem set header and the admin set editor; the editor delete action uses full-size topbar button sizing while the list keeps compact row actions.
 - **Problem-set writeups** — `/problem-sets/[slug]/writeups` lets signed-in users post LaTeX/HTML solution notes with up to four images, then sort by latest/top and upvote/downvote posts. Authors can delete their own writeups with confirmation; admins can delete any writeup. `/writeups` is the sidebar directory for latest/top writeups and problem-set search. Persistence uses new `Writeup`, `WriteupImage`, and `WriteupVote` Prisma models plus `lib/writeup-images.ts`; image bytes are stored through the existing storage layer and streamed via `/api/files/[id]`.

DBSMO/Projects/dbsmo/Components.md

@@ -39,7 +39,7 @@ This note maps important [[dbsmo]] UI/components to their source files and usage
 - Writeup header link in `app/problem-sets/[slug]/page.tsx`: icon link next to `BookmarkButton` that opens `/problem-sets/[slug]/writeups`.
 - `WriteupsPage` and `WriteupsClient` in `app/problem-sets/[slug]/writeups/`: server/client pair for set writeups. The server page handles auth, set visibility, sorting, and initial data; the client component handles the composer, image selection, optimistic voting, confirm-delete controls, and feed cards rendered with `LatexStatement`.
 - `WriteupsDirectoryPage` in `app/writeups/page.tsx`: sidebar community writeups page with latest/top tabs and problem-set-focused search suggestions; it reuses `WriteupsClient` without the composer.
-- `LatexStatement` in `app/problem-sets/[slug]/latex-statement.tsx`: server-side KaTeX renderer for LaTeX/HTML-style statements and imported image assets. It detects delimited and bare display environments, loads the official `mhchem` extension, and applies `lib/latex-compat.ts` before rendering. Compatibility converts document wrappers and common table environments to arrays while preserving `trust: false` and explicit expansion/size limits (sources: named files, `tests/latex-statement.test.ts`, `docs/latex-support.md`).
+- `LatexStatement` in `app/problem-sets/[slug]/latex-statement.tsx`: server-side KaTeX renderer for LaTeX/HTML-style statements and imported image assets. It detects delimited and bare display environments, loads the official `mhchem` extension, and applies `lib/latex-compat.ts` before rendering. Compatibility converts document wrappers and common table environments to arrays, and repairs legacy contest currency forms such as `\textdollar` and `\54`, while preserving `trust: false` and explicit expansion/size limits (sources: named files, `tests/latex-statement.test.ts`, `docs/latex-support.md`).
 
 ## Practice and Games
 

README.md

@@ -55,5 +55,6 @@ Session updates from the CodeGraph/Second Brain indexing pass onward:
 - Removed the global yellow wavy eyebrow/title underlines and moved the handwritten character into stable two-pass ink borders for cards, panels, controls, and form fields.
 - Restored the desktop sidebar as a compact icon rail that expands on hover/focus, preserved the stable mobile sheet, and introduced a shared simplified Sigma favicon/landing mark.
 - Upgraded KaTeX to v0.17, enabled the official `mhchem` extension, and added secure compatibility rendering for document wrappers and table environments such as `tabular`, `tabular*`, `tabularx`, and `longtable`.
+- Fixed imported contest currency notation so full-LaTeX `\textdollar` and legacy sequences such as `\54` render as dollar amounts instead of KaTeX errors.
 
 © 2026 Cosmic Crusader

docs/latex-support.md

@@ -8,7 +8,8 @@ DBSMO renders mathematical LaTeX with KaTeX `0.17.x` in `app/problem-sets/[slug]
 - Display math: `$$...$$` and `\[...\]`.
 - Bare display environments mixed with prose, including `array`, matrix variants, `align`, `gather`, `equation`, `cases`, and `CD`.
 - Chemistry through KaTeX's official `mhchem` extension, for example `$\ce{2H2 + O2 -> 2H2O}$`.
-- Common shorthand macros: `\RR`, `\NN`, `\ZZ`, `\QQ`, `\CC`, and `\degree`.
+- Common shorthand macros: `\RR`, `\NN`, `\ZZ`, `\QQ`, `\CC`, `\degree`, and `\textdollar`.
+- Legacy contest imports that encode currency as an invalid backslash-number sequence such as `\54`; this is normalized to `\$54` before rendering.
 - Imported image tokens such as `[[img:diagram1]]`; images remain separate from LaTeX and are served through the application's validated asset path.
 
 ## Table Compatibility

lib/latex-compat.ts

@@ -10,6 +10,7 @@ export const KATEX_COMPAT_MACROS: Record<string, string> = {
   "\\QQ": "\\mathbb{Q}",
   "\\CC": "\\mathbb{C}",
   "\\degree": "^{\\circ}",
+  "\\textdollar": "\\$",
 };
 
 type BracedGroup = {
@@ -204,6 +205,7 @@ export function normalizeLatexStatementSource(value: string): string {
 
 export function normalizeLatexForKatex(value: string): string {
   let normalized = normalizeLatexStatementSource(value);
+  normalized = normalized.replace(/(^|[^\\])\\(?=\d)/g, "$1\\$");
   normalized = convertTabularEnvironment(normalized, "tabular*");
   normalized = convertTabularEnvironment(normalized, "tabularx");
   normalized = convertTabularEnvironment(normalized, "longtable");

tests/latex-statement.test.ts

@@ -87,4 +87,19 @@ x & $y$ \\
     expect(html).toContain(String.raw`\ce{H2 + O2`);
     expect(html).not.toContain("katex-error");
   });
+
+  it("renders legacy currency commands from imported contest problems", () => {
+    const html = renderToStaticMarkup(
+      React.createElement(LatexStatement, {
+        statement: String.raw`Sale prices are $50\%$ below the original price, with another $20\%$ discount.
+A coat originally costs $\textdollar180$. Choose $\text{(A)}\ \54 \qquad \text{(B)}\ \72 \qquad \text{(C)}\ \90$.`,
+        format: "LATEX",
+      }),
+    );
+
+    expect(html).toContain("Sale prices are");
+    expect(html).toContain("50");
+    expect(html).toContain("180");
+    expect(html).not.toContain("katex-error");
+  });
 });