Preserve global typography and metadata in MJML exports

packages/email-renderer/test/mjml-brand.test.ts

@@ -0,0 +1,30 @@
+import { expect, test } from "bun:test";
+import { createRequire } from "node:module";
+import type { BlockDocument } from "@wrnexus/blocks";
+import { renderEmail } from "../src/index.ts";
+
+const compile = createRequire(import.meta.url)("mjml");
+
+test("MJML preserves document metadata and global typography in compiled HTML", async () => {
+  const document: BlockDocument = {
+    schemaVersion: 1, kind: "email", meta: { subject: 'Brand & "News" <today>', preheader: 'Preview <safe> & useful', lang: "en" }, theme: { tokens: {} },
+    root: { id: "root", type: "layout.email-document", version: 1, props: { width: "600", fontFamily: "Georgia, serif", textColor: "#123456" }, styles: {}, slots: {
+      content: [{ id: "text", type: "content.text", version: 1, props: { text: "Brand text" }, styles: {}, slots: {} }, { id: "button", type: "content.button", version: 1, props: { label: "Brand action", href: "https://example.com" }, styles: {}, slots: {} }],
+    } },
+  };
+  const before = structuredClone(document);
+  const result = await renderEmail(document, { mjml: true });
+  expect(result.ok).toBe(true);
+  if (!result.ok) return;
+  const source = result.value.exports!.mjml!;
+  expect(source).toContain('<mj-title>Brand &amp; &quot;News&quot; &lt;today&gt;</mj-title>');
+  expect(source).toContain('<mj-preview>Preview &lt;safe&gt; &amp; useful</mj-preview>');
+  expect(source).toContain('<mj-all font-family="Georgia, serif" />');
+  const compiled = await compile(source, { validationLevel: "strict", minify: false });
+  expect(compiled.errors).toEqual([]);
+  expect(compiled.html).toContain("font-family:Georgia, serif");
+  expect(compiled.html).toContain("color:#123456");
+  expect(compiled.html).toContain("Preview &lt;safe&gt; &amp; useful");
+  expect(compiled.html).not.toContain("<safe>");
+  expect(document).toEqual(before);
+});