From bf2715ed67f290726fc6d4c85c203ca8f74cc907 Mon Sep 17 00:00:00 2001
From: Bjorn Lu <bjornlu.dev@gmail.com>
Date: Wed, 12 Nov 2025 12:49:44 +0800
Subject: [PATCH] feat: prevent `$` symbol selection in shell code (#5025)

---
 src/client/app/composables/copyCode.ts |  9 ++++---
 src/node/markdown/plugins/highlight.ts | 36 ++++++++++++++++++++++++++
 src/shared/shared.ts                   |  5 ++++
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/src/client/app/composables/copyCode.ts b/src/client/app/composables/copyCode.ts
index 4d35e012..3d920a85 100644
--- a/src/client/app/composables/copyCode.ts
+++ b/src/client/app/composables/copyCode.ts
@@ -1,6 +1,6 @@
 import { inBrowser } from 'vitepress'
+import { isShell } from '../../shared'
 
-const shellRE = /language-(shellscript|shell|bash|sh|zsh)/
 const ignoredNodes = ['.vp-copy-ignore', '.diff.remove'].join(', ')
 
 export function useCopyCode() {
@@ -15,8 +15,6 @@ export function useCopyCode() {
           return
         }
 
-        const isShell = shellRE.test(parent.className)
-
         // Clone the node and remove the ignored nodes
         const clone = sibling.cloneNode(true) as HTMLElement
         clone.querySelectorAll(ignoredNodes).forEach((node) => node.remove())
@@ -26,7 +24,10 @@ export function useCopyCode() {
 
         let text = clone.textContent || ''
 
-        if (isShell) {
+        // NOTE: Any changes to this the code here may also need to update
+        // `transformerDisableShellSymbolSelect` in `src/node/markdown/plugins/highlight.ts`
+        const lang = /language-(\w+)/.exec(parent.className)?.[1] || ''
+        if (isShell(lang)) {
           text = text.replace(/^ *(\$|>) /gm, '').trim()
         }
 
diff --git a/src/node/markdown/plugins/highlight.ts b/src/node/markdown/plugins/highlight.ts
index 8f427823..5862aff1 100644
--- a/src/node/markdown/plugins/highlight.ts
+++ b/src/node/markdown/plugins/highlight.ts
@@ -11,6 +11,7 @@ import c from 'picocolors'
 import type { BundledLanguage, ShikiTransformer } from 'shiki'
 import { createHighlighter, guessEmbeddedLanguages, isSpecialLang } from 'shiki'
 import type { Logger } from 'vite'
+import { isShell } from '../../shared'
 import type { MarkdownOptions, ThemeOptions } from '../markdown'
 
 const nanoid = customAlphabet('abcdefghijklmnopqrstuvwxyz', 10)
@@ -47,6 +48,40 @@ function attrsToLines(attrs: string): TransformerCompactLineOption[] {
   }))
 }
 
+/**
+ * Prevents the leading '$' symbol etc from being selectable/copyable. Also
+ * normalizes its syntax so there's no leading spaces, and only a single
+ * trailing space.
+ *
+ * NOTE: Any changes to this function may also need to update
+ * `src/client/app/composables/copyCode.ts`
+ */
+function transformerDisableShellSymbolSelect(): ShikiTransformer {
+  return {
+    name: 'vitepress:disable-shell-symbol-select',
+    tokens(tokensByLine) {
+      if (!isShell(this.options.lang)) return
+
+      for (const tokens of tokensByLine) {
+        if (tokens.length < 2) continue
+
+        // The first token should only be a symbol token
+        const firstTokenText = tokens[0].content.trim()
+        if (firstTokenText !== '$' && firstTokenText !== '>') continue
+
+        // The second token must have a leading space (separates the symbol)
+        if (tokens[1].content[0] !== ' ') continue
+
+        tokens[0].content = firstTokenText + ' '
+        tokens[0].htmlStyle ??= {}
+        tokens[0].htmlStyle['user-select'] = 'none'
+        tokens[0].htmlStyle['-webkit-user-select'] = 'none'
+        tokens[1].content = tokens[1].content.slice(1)
+      }
+    }
+  }
+}
+
 export async function highlight(
   theme: ThemeOptions,
   options: MarkdownOptions,
@@ -83,6 +118,7 @@ export async function highlight(
     }),
     transformerNotationHighlight(),
     transformerNotationErrorLevel(),
+    transformerDisableShellSymbolSelect(),
     {
       name: 'vitepress:add-dir',
       pre(node) {
diff --git a/src/shared/shared.ts b/src/shared/shared.ts
index c556e723..f16a25ba 100644
--- a/src/shared/shared.ts
+++ b/src/shared/shared.ts
@@ -353,3 +353,8 @@ type ObjectType = Record<PropertyKey, any>
 export function isObject(value: unknown): value is ObjectType {
   return Object.prototype.toString.call(value) === '[object Object]'
 }
+
+const shellLangs = ['shellscript', 'shell', 'bash', 'sh', 'zsh']
+export function isShell(lang: string): boolean {
+  return shellLangs.includes(lang)
+}