From e4d07cf93772611d8c3c19faadabd6045965a6bf Mon Sep 17 00:00:00 2001
From: Brennan Benson <79079362+brennanb2025@users.noreply.github.com>
Date: Thu, 5 Nov 2026 14:28:37 -0800
Subject: [PATCH] Keep prices readable in chat (#38651)

* fix(chat): keep shell paths and prices as written

* Use the common inline dollar rule in chat
---
 .../NativeChatMessageRow.fixture.tsx          | 40 +++++++++++++++
 .../sidebar/CommentMarkdown.dollars.test.tsx  | 50 +++++++++++++++++++
 .../components/sidebar/chat-markdown-math.ts  | 33 ++++++++----
 3 files changed, 113 insertions(+), 10 deletions(-)
 create mode 100644 src/renderer/src/components/sidebar/CommentMarkdown.dollars.test.tsx

diff --git a/src/renderer/src/components/native-chat/NativeChatMessageRow.fixture.tsx b/src/renderer/src/components/native-chat/NativeChatMessageRow.fixture.tsx
index 0ff37b72124..a9f46fa48e1 100644
--- a/src/renderer/src/components/native-chat/NativeChatMessageRow.fixture.tsx
+++ b/src/renderer/src/components/native-chat/NativeChatMessageRow.fixture.tsx
@@ -53,3 +53,43 @@ export const rejected = defineFixture({
   width: 480,
   render: () => <RecordedSteer state="rejected" />
 })
+
+export const dollars = defineFixture({
+  width: 640,
+  render: () => (
+    <div className="native-chat-appearance space-y-4 p-4">
+      <MessageRow
+        message={{
+          id: 'dollar-question',
+          role: 'user',
+          timestamp: 0,
+          source: 'transcript',
+          blocks: [{ type: 'text', text: 'Can I use `$HOME/bin:$PATH`? It costs $5 or $10.' }]
+        }}
+        expandSignal={false}
+        onScrollMessageToTop={() => {}}
+      />
+      <MessageRow
+        message={{
+          id: 'dollar-answer',
+          role: 'assistant',
+          timestamp: 1,
+          source: 'transcript',
+          blocks: [
+            {
+              type: 'text',
+              text: [
+                'Set $ORCA_HOME then run echo $PATH. Use `$HOME/bin:$PATH` or `$HOME/${PATH}`. In PowerShell, use `$env:PATH;$env:TEMP`.',
+                'Prices: $5 + tax$ stays as written. Inline code stays literal: `echo $HOME`.',
+                String.raw`Real math: the $n$th term, $x^2$, $5+2$, and \(5 + 2\).`,
+                '$$5 + 2$$'
+              ].join('\n\n')
+            }
+          ]
+        }}
+        expandSignal={false}
+        onScrollMessageToTop={() => {}}
+      />
+    </div>
+  )
+})
diff --git a/src/renderer/src/components/sidebar/CommentMarkdown.dollars.test.tsx b/src/renderer/src/components/sidebar/CommentMarkdown.dollars.test.tsx
new file mode 100644
index 00000000000..025e2d291bd
--- /dev/null
+++ b/src/renderer/src/components/sidebar/CommentMarkdown.dollars.test.tsx
@@ -0,0 +1,50 @@
+// @vitest-environment happy-dom
+import { cleanup, render, waitFor } from '@testing-library/react'
+import { afterEach, beforeAll, expect, it, vi } from 'vitest'
+import CommentMarkdown from './CommentMarkdown'
+
+vi.mock('./CommentMermaidBlock', () => ({ default: () => null }))
+afterEach(cleanup)
+
+beforeAll(async () => {
+  const view = render(<CommentMarkdown content="$x$" math />)
+  await waitFor(() => expect(view.container.querySelector('.katex')).not.toBeNull())
+  view.unmount()
+})
+
+it.each([false, true])('preserves prices and code (growing=%s)', (growing) => {
+  const source = [
+    'Set $ORCA_HOME then run echo $PATH; $HOME and $PATH stay literal.',
+    'It costs $5 or $10; $5 + tax$ is the cost.',
+    'Run `echo $HOME/bin:$PATH` and `$VAR`.'
+  ].join('\n\n')
+  const view = render(
+    <CommentMarkdown content={source} math growing={growing} variant="document" />
+  )
+  expect(view.container.querySelector('.katex, .katex-error')).toBeNull()
+  expect(Array.from(view.container.querySelectorAll('p'), (node) => node.textContent)).toEqual([
+    'Set $ORCA_HOME then run echo $PATH; $HOME and $PATH stay literal.',
+    'It costs $5 or $10; $5 + tax$ is the cost.',
+    'Run echo $HOME/bin:$PATH and $VAR.'
+  ])
+  expect(Array.from(view.container.querySelectorAll('code'), (node) => node.textContent)).toEqual([
+    'echo $HOME/bin:$PATH',
+    '$VAR'
+  ])
+
+  view.rerender(
+    <CommentMarkdown
+      content={String.raw`Use $x^2$ for the $n$th term. Costs $5 + tax, but $y$ is math. Keep $5 + 2$ typed; render $5+2$, \(5 + 2\), and $$5 + 2$$.
+
+Costs $5, and f(x)=$!x$. Cost $5 + tax$x$ applies. Keep $\$3 + x$, $x^*$s, and $"x"$s as math.`}
+      math
+      growing={growing}
+      variant="document"
+    />
+  )
+  expect(
+    Array.from(view.container.querySelectorAll('annotation'), (node) => node.textContent)
+  ).toEqual(['x^2', 'n', 'y', '5+2', '5 + 2', '5 + 2', '!x', 'x', '\\$3 + x', 'x^*', '"x"'])
+  expect(view.container.textContent).toContain('Costs $5 + tax, but ')
+  expect(view.container.textContent).toContain('Keep $5 + 2$ typed; render ')
+})
diff --git a/src/renderer/src/components/sidebar/chat-markdown-math.ts b/src/renderer/src/components/sidebar/chat-markdown-math.ts
index 966dd33d5cc..d0f207d0091 100644
--- a/src/renderer/src/components/sidebar/chat-markdown-math.ts
+++ b/src/renderer/src/components/sidebar/chat-markdown-math.ts
@@ -28,13 +28,15 @@ declare module 'micromark-util-types' {
 
 const lineEnding = (code: Code): boolean => code !== null && code < -2
 const whitespace = (code: Code): boolean => code === null || code < 0 || code === 32
-const digit = (code: Code): boolean => code !== null && code >= 48 && code <= 57
+const digit = (code: Code): code is number => code !== null && code >= 48 && code <= 57
+const currencyTerminators = new Set([33, 41, 58, 59, 63])
 
 type ExhaustedSearch = { from: number; to: number; last: Map<number, number> }
 
 function construct(flow: boolean): Construct {
   const searches = new WeakMap<TokenizeContext, Map<string, ExhaustedSearch>>()
   const tokenize: Tokenizer = function (effects, ok, nok) {
+    const afterWhitespace = () => whitespace(this.previous)
     const knowledge = flow ? undefined : (searches.get(this) ?? new Map<string, ExhaustedSearch>())
     if (knowledge) {
       searches.set(this, knowledge)
@@ -48,6 +50,7 @@ function construct(flow: boolean): Construct {
     let escaped = false
     let candidate: Token
     let closeSize = 0
+    let closeAfterWhitespace = false
     const continuation: Construct = {
       partial: true,
       tokenize(e, yes, no) {
@@ -126,8 +129,23 @@ function construct(flow: boolean): Construct {
       if (opener === '$' && whitespace(code)) {
         return nok(code)
       }
+      if (opener === '$' && digit(code)) {
+        effects.enter('chatMathData')
+        return leadingNumber(code)
+      }
       return between(code)
     }
+    function leadingNumber(code: Code): State | undefined {
+      if (digit(code) || code === 44 || code === 46) {
+        effects.consume(code)
+        body += String.fromCharCode(code)
+        return leadingNumber
+      }
+      if (whitespace(code) || (code !== null && currencyTerminators.has(code))) {
+        return nok(code)
+      }
+      return data(code)
+    }
     function between(code: Code): State | undefined {
       if (code === null) {
         return flow ? finish(code) : exhausted(code)
@@ -136,7 +154,7 @@ function construct(flow: boolean): Construct {
         if (flow) {
           return effects.attempt(continuation, continued, finish)(code)
         }
-        if (opener === '$' || opener === '\\(') {
+        if (opener === '\\(') {
           return exhausted(code)
         }
         effects.enter('lineEnding')
@@ -146,6 +164,7 @@ function construct(flow: boolean): Construct {
         return between
       }
       if (code === 36 && opener.startsWith('$')) {
+        closeAfterWhitespace = afterWhitespace()
         candidate = effects.enter('chatMathMarker')
         closeSize = 0
         return dollarClose(code)
@@ -160,7 +179,7 @@ function construct(flow: boolean): Construct {
       return between(code)
     }
     function dollarClose(code: Code): State | undefined {
-      if (code === 36) {
+      if (code === 36 && (opener !== '$' || closeSize === 0)) {
         effects.consume(code)
         closeSize++
         return dollarClose
@@ -174,13 +193,7 @@ function construct(flow: boolean): Construct {
         body += '$'.repeat(closeSize)
         return between(code)
       }
-      if (
-        opener === '$' &&
-        (/\s/.test(body.at(-1) ?? '') ||
-          digit(code) ||
-          (/^[+-]?\d[\d,]*(?:\.\d+)?(?:[^\p{ASCII}]|\s)/u.test(body) &&
-            !/[\\_^=<>+*/{}-]/.test(body)))
-      ) {
+      if (opener === '$' && (closeAfterWhitespace || digit(code))) {
         return nok(code)
       }
       effects.exit('chatMathMarker')