Add Shiki as an alternative to Prism (#2497)

* [ci] yarn format

* Added shiki to markdown-remark

* Upgraded astro shiki

* Added minimal example

* Changed defaults to match <Code />

* Replace `shiki` with `astro` classes

* Added documentation

* Updated Astro code to use new `codeToHtml`

* Added changesets

* Added basic test

* Updated tests a bit

Co-authored-by: JuanM04 <JuanM04@users.noreply.github.com>

26 files changed, 356 insertions, 9 deletions

diff --git a/.changeset/rotten-planets-love.md b/.changeset/rotten-planets-love.md
new file mode 100644
index 000000000..aa67307eb
--- /dev/null
+++ b/.changeset/rotten-planets-love.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/markdown-remark': patch
+---
+
+Add Shiki as an alternative to Prism
diff --git a/.changeset/tiny-owls-dress.md b/.changeset/tiny-owls-dress.md
new file mode 100644
index 000000000..82e35f3a2
--- /dev/null
+++ b/.changeset/tiny-owls-dress.md
@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Bumped Shiki version
diff --git a/docs/src/pages/en/guides/markdown-content.md b/docs/src/pages/en/guides/markdown-content.md
index 8233a8af4..b5e33d5b2 100644
--- a/docs/src/pages/en/guides/markdown-content.md
+++ b/docs/src/pages/en/guides/markdown-content.md
@@ -33,7 +33,6 @@ In addition to custom components inside the [`<Markdown>` component](/en/guides/
 - [GitHub-flavored Markdown](https://github.com/remarkjs/remark-gfm)
 - [remark-smartypants](https://github.com/silvenon/remark-smartypants)
 - [rehype-slug](https://github.com/rehypejs/rehype-slug)
-- [Prism](https://prismjs.com/)
 
 Also, Astro supports third-party plugins for Markdown. You can provide your plugins in `astro.config.mjs`.
 
@@ -85,6 +84,27 @@ export default {
 };
 ```
 
+### Syntax Highlighting
+
+Astro comes with built-in support for [Prism](https://prismjs.com/) and [Shiki](https://shiki.matsu.io/). By default, Prism is enabled. You can modify this behavior by updating the `@astrojs/markdown-remark` options:
+
+```js
+// astro.config.mjs
+export default {
+  markdownOptions: {
+    render: [
+      '@astrojs/markdown-remark',
+      {
+        // Pick a syntax highlighter. Can be 'prism' (default), 'shiki' or false to disable any highlighting.
+        syntaxHighlight: 'prism',
+        // If you are using shiki, here you can define a global theme.
+        shikiTheme: 'github-dark',
+      },
+    ],
+  },
+};
+```
+
 ## Markdown Pages
 
 Astro treats any `.md` files inside of the `/src/pages` directory as pages. These files can contain frontmatter, but are otherwise processed as plain markdown files and do not support components. If you're looking to embed rich components in your markdown, take a look at the [Markdown Component](#astros-markdown-component) section.
diff --git a/examples/with-markdown-shiki/.gitignore b/examples/with-markdown-shiki/.gitignore
new file mode 100644
index 000000000..c82467453
--- /dev/null
+++ b/examples/with-markdown-shiki/.gitignore
@@ -0,0 +1,17 @@
+# build output
+dist
+
+# dependencies
+node_modules/
+
+# logs
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# environment variables
+.env
+.env.production
+
+# macOS-specific files
+.DS_Store
diff --git a/examples/with-markdown-shiki/.npmrc b/examples/with-markdown-shiki/.npmrc
new file mode 100644
index 000000000..0cc653b2c
--- /dev/null
+++ b/examples/with-markdown-shiki/.npmrc
@@ -0,0 +1,2 @@
+## force pnpm to hoist 
+shamefully-hoist = true
\ No newline at end of file
diff --git a/examples/with-markdown-shiki/.stackblitzrc b/examples/with-markdown-shiki/.stackblitzrc
new file mode 100644
index 000000000..43798ecff
--- /dev/null
+++ b/examples/with-markdown-shiki/.stackblitzrc
@@ -0,0 +1,6 @@
+{
+  "startCommand": "npm start",
+  "env": {
+    "ENABLE_CJS_IMPORTS": true
+  }
+}
\ No newline at end of file
diff --git a/examples/with-markdown-shiki/README.md b/examples/with-markdown-shiki/README.md
new file mode 100644
index 000000000..d97d1855d
--- /dev/null
+++ b/examples/with-markdown-shiki/README.md
@@ -0,0 +1,12 @@
+# Astro Example: Markdown with Shiki
+
+```
+npm init astro -- --template with-markdown-shiki
+```
+
+[![Open in StackBlitz](https://developer.stackblitz.com/img/open_in_stackblitz.svg)](https://stackblitz.com/github/withastro/astro/tree/latest/examples/with-markdown)
+
+This example showcases Astro's [built-in Markdown support](../../docs/markdown.md).
+
+- `src/pages/index.astro` uses Astro's `<Markdown>` component.
+- `src/pages/other.md` is a treated as a page entrypoint and uses a `layout`.
diff --git a/examples/with-markdown-shiki/astro.config.mjs b/examples/with-markdown-shiki/astro.config.mjs
new file mode 100644
index 000000000..bb2a78321
--- /dev/null
+++ b/examples/with-markdown-shiki/astro.config.mjs
@@ -0,0 +1,22 @@
+// Full Astro Configuration API Documentation:
+// https://docs.astro.build/reference/configuration-reference
+
+// @type-check enabled!
+// VSCode and other TypeScript-enabled text editors will provide auto-completion,
+// helpful tooltips, and warnings if your exported object is invalid.
+// You can disable this by removing "@ts-check" and `@type` comments below.
+import astroRemark from '@astrojs/markdown-remark';
+
+// @ts-check
+export default /** @type {import('astro').AstroUserConfig} */ ({
+	// Enable Custom Markdown options, plugins, etc.
+	markdownOptions: {
+		render: [
+			astroRemark,
+			{
+				syntaxHighlight: 'shiki',
+				shikiTheme: 'dracula',
+			},
+		],
+	},
+});
diff --git a/examples/with-markdown-shiki/package.json b/examples/with-markdown-shiki/package.json
new file mode 100644
index 000000000..1573fe586
--- /dev/null
+++ b/examples/with-markdown-shiki/package.json
@@ -0,0 +1,14 @@
+{
+  "name": "@example/with-markdown-shiki",
+  "version": "0.0.1",
+  "private": true,
+  "scripts": {
+    "dev": "astro dev",
+    "start": "astro dev",
+    "build": "astro build",
+    "preview": "astro preview"
+  },
+  "devDependencies": {
+    "astro": "^0.22.20"
+  }
+}
diff --git a/examples/with-markdown-shiki/public/favicon.ico b/examples/with-markdown-shiki/public/favicon.ico
new file mode 100644
index 000000000..578ad458b
--- /dev/null
+++ b/examples/with-markdown-shiki/public/favicon.ico
diff --git a/examples/with-markdown-shiki/sandbox.config.json b/examples/with-markdown-shiki/sandbox.config.json
new file mode 100644
index 000000000..9178af77d
--- /dev/null
+++ b/examples/with-markdown-shiki/sandbox.config.json
@@ -0,0 +1,11 @@
+{
+  "infiniteLoopProtection": true,
+  "hardReloadOnChange": false,
+  "view": "browser",
+  "template": "node",
+  "container": {
+    "port": 3000,
+    "startScript": "start",
+    "node": "14"
+  }
+}
diff --git a/examples/with-markdown-shiki/src/layouts/main.astro b/examples/with-markdown-shiki/src/layouts/main.astro
new file mode 100644
index 000000000..1c4441a11
--- /dev/null
+++ b/examples/with-markdown-shiki/src/layouts/main.astro
@@ -0,0 +1,20 @@
+---
+const { content } = Astro.props;
+---
+
+<html lang={content.lang || 'en'}>
+	<head>
+		<meta charset="utf-8" />
+
+		<link rel="icon" type="image/x-icon" href="/favicon.ico" />
+
+		<title>{content.title}</title>
+
+		<style global>
+			@import "../styles/global.css";
+		</style>
+	</head>
+	<body>
+		<slot />
+	</body>
+</html>
diff --git a/examples/with-markdown-shiki/src/pages/index.md b/examples/with-markdown-shiki/src/pages/index.md
new file mode 100644
index 000000000..89e58184f
--- /dev/null
+++ b/examples/with-markdown-shiki/src/pages/index.md
@@ -0,0 +1,14 @@
+---
+title: Shiki demo
+layout: ../layouts/main.astro
+---
+
+# Shiki demo
+
+```js
+var foo = 'bar';
+
+function doSomething() {
+  return foo;
+}
+```
diff --git a/examples/with-markdown-shiki/src/styles/global.css b/examples/with-markdown-shiki/src/styles/global.css
new file mode 100644
index 000000000..e8b9d0314
--- /dev/null
+++ b/examples/with-markdown-shiki/src/styles/global.css
@@ -0,0 +1,54 @@
+pre,
+code {
+	color: #d4d4d4;
+	font-size: 14px;
+	font-family: Consolas, Monaco, 'Andale Mono', 'Ubuntu Mono', monospace;
+	line-height: 1.5;
+	direction: ltr;
+	white-space: pre;
+	text-align: left;
+	text-shadow: none;
+	word-break: normal;
+	word-spacing: normal;
+	-moz-tab-size: 4;
+	-o-tab-size: 4;
+	tab-size: 4;
+	-webkit-hyphens: none;
+	-moz-hyphens: none;
+	-ms-hyphens: none;
+	hyphens: none;
+}
+
+pre::selection,
+code::selection {
+	text-shadow: none;
+	background: #b3d4fc;
+}
+
+@media print {
+	pre,
+	code {
+		text-shadow: none;
+	}
+}
+
+pre {
+	margin: 0.5rem 0 16px;
+	padding: 0.8rem 1rem 0.9rem;
+	overflow: auto;
+	background: #282a36;
+	border-radius: 4px;
+}
+
+:not(pre) > code {
+	padding: 0.1em 0.3em;
+	color: #db4c69;
+	background: #f9f2f4;
+	border-radius: 0.3em;
+	white-space: pre-wrap;
+}
+
+body {
+	max-width: 900px;
+	margin: auto;
+}
diff --git a/examples/with-markdown-shiki/tsconfig.json b/examples/with-markdown-shiki/tsconfig.json
new file mode 100644
index 000000000..8e881cf9c
--- /dev/null
+++ b/examples/with-markdown-shiki/tsconfig.json
@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "moduleResolution": "node"
+  }
+}
diff --git a/packages/astro/components/Code.astro b/packages/astro/components/Code.astro
index acebfce04..37f23a99a 100644
--- a/packages/astro/components/Code.astro
+++ b/packages/astro/components/Code.astro
@@ -43,7 +43,7 @@ function repairShikiTheme(html: string): string {
 }
 
 const highlighter = await shiki.getHighlighter({ theme });
-const _html = highlighter.codeToHtml(code, lang);
+const _html = highlighter.codeToHtml(code, { lang });
 const html = repairShikiTheme(_html);
 ---
 
diff --git a/packages/astro/package.json b/packages/astro/package.json
index 2891c1797..a1b3b11c6 100644
--- a/packages/astro/package.json
+++ b/packages/astro/package.json
@@ -97,7 +97,7 @@
     "sass": "^1.43.4",
     "semver": "^7.3.5",
     "send": "^0.17.1",
-    "shiki": "^0.9.10",
+    "shiki": "^0.10.0",
     "shorthash": "^0.0.2",
     "slash": "^4.0.0",
     "sourcemap-codec": "^1.4.8",
diff --git a/packages/astro/test/astro-markdown-shiki.test.js b/packages/astro/test/astro-markdown-shiki.test.js
new file mode 100644
index 000000000..f5e254e1b
--- /dev/null
+++ b/packages/astro/test/astro-markdown-shiki.test.js
@@ -0,0 +1,53 @@
+import { expect } from 'chai';
+import cheerio from 'cheerio';
+import { loadFixture } from './test-utils.js';
+import markdownRemark from '@astrojs/markdown-remark';
+
+describe('Astro Markdown Shiki', () => {
+	let fixture;
+
+	before(async () => {
+		fixture = await loadFixture({
+			projectRoot: './fixtures/astro-markdown-shiki/',
+			markdownOptions: {
+				render: [
+					markdownRemark,
+					{
+						syntaxHighlight: 'shiki',
+						shikiTheme: 'github-light',
+					},
+				],
+			},
+			buildOptions: {
+				sitemap: false,
+			},
+		});
+		await fixture.build();
+	});
+
+	it('Can render markdown with shiki', async () => {
+		const html = await fixture.readFile('/index.html');
+		const $ = cheerio.load(html);
+
+		// There should be no HTML from Prism
+		expect($('.token')).to.have.lengthOf(0);
+
+		expect($('pre')).to.have.lengthOf(1);
+		expect($('pre').hasClass('astro-code')).to.equal(true);
+		expect($('pre').attr().style).to.equal('background-color: #ffffff');
+	});
+
+	it('Can render Astro <Markdown> with shiki', async () => {
+		const html = await fixture.readFile('/astro/index.html');
+		const $ = cheerio.load(html);
+
+		// There should be no HTML from Prism
+		expect($('.token')).to.have.lengthOf(0);
+
+		expect($('pre')).to.have.lengthOf(2);
+
+		expect($('span.line')).to.have.lengthOf(2);
+		expect($('span.line').get(0).children).to.have.lengthOf(1);
+		expect($('span.line').get(1).children).to.have.lengthOf(5);
+	});
+});
diff --git a/packages/astro/test/fixtures/astro-markdown-shiki/src/layouts/content.astro b/packages/astro/test/fixtures/astro-markdown-shiki/src/layouts/content.astro
new file mode 100644
index 000000000..925a243a9
--- /dev/null
+++ b/packages/astro/test/fixtures/astro-markdown-shiki/src/layouts/content.astro
@@ -0,0 +1,10 @@
+<html>
+  <head>
+    <!-- Head Stuff -->
+  </head>
+  <body>
+    <div class="container">
+      <slot></slot>
+    </div>
+  </body>
+</html>
diff --git a/packages/astro/test/fixtures/astro-markdown-shiki/src/pages/astro.astro b/packages/astro/test/fixtures/astro-markdown-shiki/src/pages/astro.astro
new file mode 100644
index 000000000..d3a3493a6
--- /dev/null
+++ b/packages/astro/test/fixtures/astro-markdown-shiki/src/pages/astro.astro
@@ -0,0 +1,18 @@
+---
+import { Markdown } from 'astro/components';
+import Layout from '../layouts/content.astro';
+---
+
+<Layout>
+	<Markdown>
+		# Hello world
+
+		```
+			plaintext
+		```
+
+		```js
+			console.log('JavaScript')
+		```
+	</Markdown>
+</Layout>
diff --git a/packages/astro/test/fixtures/astro-markdown-shiki/src/pages/index.md b/packages/astro/test/fixtures/astro-markdown-shiki/src/pages/index.md
new file mode 100644
index 000000000..a75170537
--- /dev/null
+++ b/packages/astro/test/fixtures/astro-markdown-shiki/src/pages/index.md
@@ -0,0 +1,24 @@
+---
+layout: ../layouts/content.astro
+---
+
+# Hello world
+
+```yaml
+apiVersion: v3
+kind: Pod
+metadata:
+  name: rss-site
+  labels:
+    app: web
+spec:
+  containers:
+    - name: front-end
+      image: nginx
+      ports:
+        - containerPort: 80
+    - name: rss-reader
+      image: nickchase/rss-php-nginx:v1
+      ports:
+        - containerPort: 88
+```
diff --git a/packages/markdown/remark/package.json b/packages/markdown/remark/package.json
index 6a0a69b45..00a023d1d 100644
--- a/packages/markdown/remark/package.json
+++ b/packages/markdown/remark/package.json
@@ -38,6 +38,7 @@
     "remark-parse": "^10.0.1",
     "remark-rehype": "^10.0.1",
     "remark-smartypants": "^2.0.0",
+    "shiki": "^0.10.0",
     "unified": "^10.1.1",
     "unist-util-map": "^3.0.0",
     "unist-util-visit": "^4.1.0"
diff --git a/packages/markdown/remark/src/index.ts b/packages/markdown/remark/src/index.ts
index e8242279a..78d645227 100644
--- a/packages/markdown/remark/src/index.ts
+++ b/packages/markdown/remark/src/index.ts
@@ -9,6 +9,7 @@ import { remarkJsx, loadRemarkJsx } from './remark-jsx.js';
 import rehypeJsx from './rehype-jsx.js';
 import rehypeEscape from './rehype-escape.js';
 import remarkPrism from './remark-prism.js';
+import remarkShiki from './remark-shiki.js';
 import remarkUnwrap from './remark-unwrap.js';
 import { loadPlugins } from './load-plugins.js';
 
@@ -37,6 +38,8 @@ export async function renderMarkdown(content: string, opts?: MarkdownRenderingOp
 	let { remarkPlugins = [], rehypePlugins = [] } = opts ?? {};
 	const scopedClassName = opts?.$?.scopedClassName;
 	const mode = opts?.mode ?? 'mdx';
+	const syntaxHighlight = opts?.syntaxHighlight ?? 'prism';
+	const shikiTheme = opts?.shikiTheme ?? 'github-dark';
 	const isMDX = mode === 'mdx';
 	const { headers, rehypeCollectHeaders } = createCollectHeaders();
 
@@ -64,7 +67,12 @@ export async function renderMarkdown(content: string, opts?: MarkdownRenderingOp
 		parser.use([scopedStyles(scopedClassName)]);
 	}
 
-	parser.use([remarkPrism(scopedClassName)]);
+	if (syntaxHighlight === 'prism') {
+		parser.use([remarkPrism(scopedClassName)]);
+	} else if (syntaxHighlight === 'shiki') {
+		parser.use([await remarkShiki(shikiTheme)]);
+	}
+
 	parser.use([[markdownToHtml as any, { allowDangerousHtml: true, passThrough: ['raw', 'mdxTextExpression', 'mdxJsxTextElement', 'mdxJsxFlowElement'] }]]);
 
 	loadedRehypePlugins.forEach(([plugin, opts]) => {
diff --git a/packages/markdown/remark/src/remark-shiki.ts b/packages/markdown/remark/src/remark-shiki.ts
new file mode 100644
index 000000000..5becad76d
--- /dev/null
+++ b/packages/markdown/remark/src/remark-shiki.ts
@@ -0,0 +1,23 @@
+import shiki from 'shiki';
+import { visit } from 'unist-util-visit';
+
+const remarkShiki = async (theme: shiki.Theme) => {
+	const highlighter = await shiki.getHighlighter({ theme });
+
+	return () => (tree: any) => {
+		visit(tree, 'code', (node) => {
+			let html = highlighter.codeToHtml(node.value, { lang: node.lang ?? 'plaintext' });
+
+			// Replace "shiki" class naming with "astro".
+			html = html.replace('<pre class="shiki"', '<pre class="astro-code"');
+			// Replace "shiki" css variable naming with "astro".
+			html = html.replace(/style="(background-)?color: var\(--shiki-/g, 'style="$1color: var(--astro-code-');
+
+			node.type = 'html';
+			node.value = html;
+			node.children = [];
+		});
+	};
+};
+
+export default remarkShiki;
diff --git a/packages/markdown/remark/src/types.ts b/packages/markdown/remark/src/types.ts
index 541d3ff27..043594c9c 100644
--- a/packages/markdown/remark/src/types.ts
+++ b/packages/markdown/remark/src/types.ts
@@ -1,10 +1,13 @@
-import * as unified from 'unified';
+import type * as unified from 'unified';
+import type * as shiki from 'shiki';
 
 export type UnifiedPluginImport = Promise<{ default: unified.Plugin }>;
 export type Plugin = string | [string, any] | UnifiedPluginImport | [UnifiedPluginImport, any];
 
 export interface AstroMarkdownOptions {
 	mode?: 'md' | 'mdx';
+	syntaxHighlight?: 'prism' | 'shiki' | false;
+	shikiTheme?: shiki.Theme;
 	remarkPlugins?: Plugin[];
 	rehypePlugins?: Plugin[];
 }
diff --git a/yarn.lock b/yarn.lock
index 4e56bd93d..b9a7d4c07 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -8152,10 +8152,10 @@ shell-quote@^1.6.1:
   resolved "https://registry.yarnpkg.com/shell-quote/-/shell-quote-1.7.3.tgz#aa40edac170445b9a431e17bb62c0b881b9c4123"
   integrity sha512-Vpfqwm4EnqGdlsBFNmHhxhElJYrdfcxPThu+ryKS5J8L/fhAwLazFZtq+S+TWZ9ANj2piSQLGj6NQg+lKPmxrw==
 
-shiki@^0.9.10:
-  version "0.9.15"
-  resolved "https://registry.yarnpkg.com/shiki/-/shiki-0.9.15.tgz#2481b46155364f236651319d2c18e329ead6fa44"
-  integrity sha512-/Y0z9IzhJ8nD9nbceORCqu6NgT9X6I8Fk8c3SICHI5NbZRLdZYFaB233gwct9sU0vvSypyaL/qaKvzyQGJBZSw==
+shiki@^0.10.0:
+  version "0.10.0"
+  resolved "https://registry.yarnpkg.com/shiki/-/shiki-0.10.0.tgz#85f21ecfa95b377ff64db6c71442c22c220e9540"
+  integrity sha512-iczxaIYeBFHTFrQPb9DVy2SKgYxC4Wo7Iucm7C17cCh2Ge/refnvHscUOxM85u57MfLoNOtjoEFUWt9gBexblA==
   dependencies:
     jsonc-parser "^3.0.0"
     vscode-oniguruma "^1.6.1"