Initial commit

index.ts

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+import { readFile } from "node:fs/promises";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+import type { Integration, IntegrationContext } from "muddle/contracts";
+import { renderMarkdown } from "muddle/markdown";
+import katex from "katex";
+
+export function renderLatex(source: string, displayMode = false): string {
+	return katex.renderToString(source, { displayMode, throwOnError: false, trust: false });
+}
+
+export function renderMathMarkdown(source: string): string {
+	const formulas: string[] = [];
+	const body = source.replace(/\$\$([\s\S]+?)\$\$|(?<!\\)\$([^$\n]+?)\$/g, (_match, display, inline) => {
+		formulas.push(renderLatex(display ?? inline, display !== undefined));
+		return `MUDDLEMATH${formulas.length - 1}END`;
+	});
+	return renderMarkdown(body).replace(/MUDDLEMATH(\d+)END/g, (_match, index) => formulas[Number(index)] ?? "");
+}
+
+export interface LatexIntegrationOptions { route?: string }
+
+export function latexIntegration(options: LatexIntegrationOptions = {}): Integration {
+	const route = options.route ?? "/_muddle/katex.css";
+	return {
+		name: "latex",
+		async setup(context: IntegrationContext) {
+			const base = dirname(fileURLToPath(import.meta.resolve("katex/package.json")));
+			const css = await readFile(join(base, "dist", "katex.min.css"), "utf8");
+			context.loader("latex-markdown", {
+				name: "latex-markdown",
+				extensions: [".latex.md", ".latex.markdown"],
+				load(file) { return { data: {}, content: renderMathMarkdown(file.source) }; },
+			});
+			context.route("GET", route, () => new Response(css, { headers: { "content-type": "text/css; charset=utf-8", "cache-control": "public, max-age=31536000, immutable" } }));
+		},
+	};
+}
+

package.json

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+{
+  "name": "@muddle/latex",
+  "type": "module",
+  "exports": "./index.ts",
+  "version": "0.1.0",
+  "peerDependencies": {
+    "muddle": "*"
+  },
+  "dependencies": {
+    "katex": "^0.19.0"
+  }
+}