feat(site-2): Make blog logic consistent with other content

sites/svelte.dev/package.json

@@ -29,7 +29,7 @@
 		"@resvg/resvg-js": "^2.4.1",
 		"@sveltejs/adapter-vercel": "^2.4.1",
 		"@sveltejs/kit": "^1.15.0",
-		"@sveltejs/site-kit": "^3.3.6",
+		"@sveltejs/site-kit": "^3.3.7",
 		"@sveltejs/vite-plugin-svelte": "^2.0.4",
 		"@types/marked": "^4.0.8",
 		"@types/prismjs": "^1.26.0",

sites/svelte.dev/src/lib/server/blog/get-blog-data.js

@@ -0,0 +1,60 @@
+// @ts-check
+import fs from 'fs';
+import { extract_frontmatter } from '../markdown';
+
+const BLOG_NAME_REGEX = /^(\d{4}-\d{2}-\d{2})-(.+)\.md$/;
+const BASE = '../../site/content/blog';
+
+/** @returns {import('./types').BlogData} */
+export function get_blog_data(base = BASE) {
+	/** @type {import('./types').BlogData} */
+	const blog_posts = [];
+
+	for (const file of fs.readdirSync(base).reverse()) {
+		if (!BLOG_NAME_REGEX.test(file)) continue;
+
+		const { date, date_formatted, slug } = get_date_and_slug(file);
+		const { metadata, body } = extract_frontmatter(fs.readFileSync(`${base}/${file}`, 'utf-8'));
+
+		blog_posts.push({
+			date,
+			date_formatted,
+			content: body,
+			description: metadata.description,
+			draft: metadata.draft === 'true',
+			slug,
+			title: metadata.title,
+			author: {
+				name: metadata.author,
+				url: metadata.authorURL
+			}
+		});
+	}
+
+	return blog_posts;
+}
+
+/** @param {import('./types').BlogData} blog_data */
+export function get_blog_list(blog_data) {
+	return blog_data.map(({ slug, date, title, description, draft }) => ({
+		slug,
+		date,
+		title,
+		description,
+		draft
+	}));
+}
+
+/** @param {string} filename */
+function get_date_and_slug(filename) {
+	const match = BLOG_NAME_REGEX.exec(filename);
+	if (!match) throw new Error(`Invalid filename for blog: '${filename}'`);
+
+	const [, date, slug] = match;
+	const [y, m, d] = date.split('-');
+	const date_formatted = `${months[+m - 1]} ${+d} ${y}`;
+
+	return { date, date_formatted, slug };
+}
+
+const months = 'Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec'.split(' ');

sites/svelte.dev/src/lib/server/blog/index.js

@@ -1,75 +1,96 @@
-import fs from 'fs';
-import { extract_frontmatter } from '../markdown';
-import { transform } from './marked';
-
-const base = '../../site/content/blog';
+// @ts-check
+import { createShikiHighlighter } from 'shiki-twoslash';
+import { SHIKI_LANGUAGE_MAP, escape, transform } from '../markdown';
 
 /**
- * @returns {import('./types').BlogPostSummary[]}
+ * @param {import('./types').BlogData} blog_data
+ * @param {string} slug
  */
-export function get_index() {
-	return fs
-		.readdirSync(base)
-		.reverse()
-		.map((file) => {
-			if (!file.endsWith('.md')) return;
+export async function get_processed_blog_post(blog_data, slug) {
+	const post = blog_data.find((post) => post.slug === slug);
 
-			const { date, slug } = get_date_and_slug(file);
+	if (!post) return null;
 
-			const content = fs.readFileSync(`${base}/${file}`, 'utf-8');
-			const { metadata } = extract_frontmatter(content);
+	const highlighter = await createShikiHighlighter({ theme: 'css-variables' });
 
-			return {
-				slug,
-				date,
-				title: metadata.title,
-				description: metadata.description,
-				draft: !!metadata.draft
-			};
-		});
-}
+	return {
+		...post,
+		content: transform(post.content, {
+			/**
+			 * @param {string} html
+			 */
+			heading(html) {
+				const title = html
+					.replace(/<\/?code>/g, '')
+					.replace(/&quot;/g, '"')
+					.replace(/&lt;/g, '<')
+					.replace(/&gt;/g, '>');
 
-/**
- * @param {string} slug
- * @returns {import('./types').BlogPost}
- */
-export function get_post(slug) {
-	for (const file of fs.readdirSync(`${base}`)) {
-		if (!file.endsWith('.md')) continue;
-		if (file.slice(11, -3) !== slug) continue;
+				return title;
+			},
+			code: (source, language) => {
+				let html = '';
 
-		const { date, date_formatted } = get_date_and_slug(file);
+				source = source
+					.replace(/^([\-\+])?((?:    )+)/gm, (match, prefix = '', spaces) => {
+						if (prefix && language !== 'diff') return match;
 
-		const content = fs.readFileSync(`${base}/${file}`, 'utf-8');
-		const { metadata, body } = extract_frontmatter(content);
+						// for no good reason at all, marked replaces tabs with spaces
+						let tabs = '';
+						for (let i = 0; i < spaces.length; i += 4) {
+							tabs += '  ';
+						}
+						return prefix + tabs;
+					})
+					.replace(/\*\\\//g, '*/');
 
-		return {
-			date,
-			date_formatted,
-			title: metadata.title,
-			description: metadata.description,
-			author: {
-				name: metadata.author,
-				url: metadata.authorURL
-			},
-			draft: !!metadata.draft,
-			content: transform(body)
-		};
-	}
-}
+				if (language === 'diff') {
+					const lines = source.split('\n').map((content) => {
+						let type = null;
+						if (/^[\+\-]/.test(content)) {
+							type = content[0] === '+' ? 'inserted' : 'deleted';
+							content = content.slice(1);
+						}
 
-/** @param {string} filename */
-function get_date_and_slug(filename) {
-	const match = /^(\d{4}-\d{2}-\d{2})-(.+)\.md$/.exec(filename);
-	if (!match) throw new Error(`Invalid filename for blog: '${filename}'`);
+						return {
+							type,
+							content: escape(content)
+						};
+					});
 
-	const [, date, slug] = match;
-	const [y, m, d] = date.split('-');
-	const date_formatted = `${months[+m - 1]} ${+d} ${y}`;
+					html = `<pre class="language-diff"><code>${lines
+						.map((line) => {
+							if (line.type) return `<span class="${line.type}">${line.content}\n</span>`;
+							return line.content + '\n';
+						})
+						.join('')}</code></pre>`;
+				} else {
+					html = highlighter.codeToHtml(source, { lang: SHIKI_LANGUAGE_MAP[language] });
 
-	return { date, date_formatted, slug };
-}
+					html = html
+						.replace(
+							/^(\s+)<span class="token comment">([\s\S]+?)<\/span>\n/gm,
+							(match, intro_whitespace, content) => {
+								// we use some CSS trickery to make comments break onto multiple lines while preserving indentation
+								const lines = (intro_whitespace + content).split('\n');
+								return lines
+									.map((line) => {
+										const match = /^(\s*)(.*)/.exec(line);
+										const indent = (match[1] ?? '').replace(/\t/g, '  ').length;
 
-const months = 'Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec'.split(' ');
+										return `<span class="token comment wrapped" style="--indent: ${indent}ch">${
+											line ?? ''
+										}</span>`;
+									})
+									.join('');
+							}
+						)
+						.replace(/\/\*…\*\//g, '…');
+				}
 
-function format_date(date) {}
+				return html;
+			},
+			codespan: (text) => '<code>' + text + '</code>'
+		})
+	};
+}