Files
shadcn-ui/apps/v4/lib/highlight-code.ts

107 lines
3.3 KiB
TypeScript

import { createHash } from "crypto"
import { LRUCache } from "lru-cache"
import { codeToHtml } from "shiki"
import type { ShikiTransformer } from "shiki"
// LRU cache for cross-request caching of highlighted code.
// Shiki highlighting is CPU-intensive and deterministic, so caching is safe.
const highlightCache = new LRUCache<string, string>({
max: 500,
ttl: 1000 * 60 * 60, // 1 hour.
})
export const transformers = [
{
code(node) {
if (node.tagName === "code") {
const raw = this.source
node.properties["__raw__"] = raw
if (raw.startsWith("npm install")) {
node.properties["__npm__"] = raw
node.properties["__yarn__"] = raw.replace("npm install", "yarn add")
node.properties["__pnpm__"] = raw.replace("npm install", "pnpm add")
node.properties["__bun__"] = raw.replace("npm install", "bun add")
}
if (raw.startsWith("npx create-")) {
node.properties["__npm__"] = raw
node.properties["__yarn__"] = raw.replace(
"npx create-",
"yarn create "
)
node.properties["__pnpm__"] = raw.replace(
"npx create-",
"pnpm create "
)
node.properties["__bun__"] = raw.replace("npx", "bunx --bun")
}
// npm create.
if (raw.startsWith("npm create")) {
node.properties["__npm__"] = raw
node.properties["__yarn__"] = raw.replace("npm create", "yarn create")
node.properties["__pnpm__"] = raw.replace("npm create", "pnpm create")
node.properties["__bun__"] = raw.replace("npm create", "bun create")
}
// npx.
if (raw.startsWith("npx")) {
node.properties["__npm__"] = raw
node.properties["__yarn__"] = raw.replace("npx", "yarn")
node.properties["__pnpm__"] = raw.replace("npx", "pnpm dlx")
node.properties["__bun__"] = raw.replace("npx", "bunx --bun")
}
// npm run.
if (raw.startsWith("npm run")) {
node.properties["__npm__"] = raw
node.properties["__yarn__"] = raw.replace("npm run", "yarn")
node.properties["__pnpm__"] = raw.replace("npm run", "pnpm")
node.properties["__bun__"] = raw.replace("npm run", "bun")
}
}
},
},
] as ShikiTransformer[]
export async function highlightCode(code: string, language: string = "tsx") {
// Create cache key from code content and language.
const cacheKey = createHash("sha256")
.update(`${language}:${code}`)
.digest("hex")
// Check cache first.
const cached = highlightCache.get(cacheKey)
if (cached) {
return cached
}
const html = await codeToHtml(code, {
lang: language,
themes: {
dark: "github-dark",
light: "github-light",
},
transformers: [
{
pre(node) {
node.properties["class"] =
"no-scrollbar min-w-0 overflow-x-auto overflow-y-auto overscroll-x-contain overscroll-y-auto px-4 py-3.5 outline-none has-[[data-highlighted-line]]:px-0 has-[[data-line-numbers]]:px-0 has-[[data-slot=tabs]]:p-0 !bg-transparent"
},
code(node) {
node.properties["data-line-numbers"] = ""
},
line(node) {
node.properties["data-line"] = ""
},
},
],
})
// Cache the result.
highlightCache.set(cacheKey, html)
return html
}