feat(scripts): add mustache render-template via Responses pages

Add HTML template kind to Responses with a seeded system email-default
template, render-template.js using Mustache, and html body support in
send-email. Templates are editable but system pages cannot be deleted.

Co-authored-by: Nasyarobby Putra <nasyarobby@gmail.com>

packages/server/scripts/render-template.js

@@ -0,0 +1,126 @@
+import Mustache from "mustache";
+
+/**
+ * @param {string} html
+ */
+function htmlToText(html) {
+  return html
+    .replace(/<style[\s\S]*?<\/style>/gi, "")
+    .replace(/<script[\s\S]*?<\/script>/gi, "")
+    .replace(/<br\s*\/?>/gi, "\n")
+    .replace(/<\/(p|div|h[1-6]|li|tr)>/gi, "\n")
+    .replace(/<li[^>]*>/gi, "- ")
+    .replace(/<[^>]+>/g, "")
+    .replace(/&nbsp;/g, " ")
+    .replace(/&amp;/g, "&")
+    .replace(/&lt;/g, "<")
+    .replace(/&gt;/g, ">")
+    .replace(/&quot;/g, '"')
+    .replace(/&#39;/g, "'")
+    .replace(/\n{3,}/g, "\n\n")
+    .trim();
+}
+
+/**
+ * @param {unknown} partialsConfig
+ */
+async function loadPartials(partialsConfig) {
+  /** @type {Record<string, string>} */
+  const partials = {};
+  if (partialsConfig == null) return partials;
+  if (typeof partialsConfig !== "object" || Array.isArray(partialsConfig)) {
+    throw new Error("config.partials must be an object");
+  }
+
+  for (const [partialName, pageName] of Object.entries(
+    /** @type {Record<string, unknown>} */ (partialsConfig),
+  )) {
+    if (typeof pageName !== "string" || pageName.length === 0) {
+      throw new Error(`config.partials.${partialName} must be a template page name`);
+    }
+    partials[partialName] = await $responses.getTemplate(pageName);
+  }
+  return partials;
+}
+
+async function renderTemplate(ctx) {
+  const templateName = ctx.config?.template;
+  if (typeof templateName !== "string" || templateName.length === 0) {
+    throw new Error("config.template is required");
+  }
+
+  const vars = ctx.data?.vars ?? ctx.data;
+  if (vars == null || typeof vars !== "object" || Array.isArray(vars)) {
+    throw new Error("data.vars must be an object");
+  }
+
+  const template = await $responses.getTemplate(templateName);
+  const partials = await loadPartials(ctx.config?.partials);
+
+  log.info(
+    {
+      template: templateName,
+      partials: Object.keys(partials),
+      varKeys: Object.keys(vars),
+    },
+    "render-template: rendering mustache template",
+  );
+
+  const html = Mustache.render(template, vars, partials);
+  const text = htmlToText(html);
+
+  return {
+    html,
+    text,
+    template: templateName,
+  };
+}
+
+renderTemplate.meta = {
+  description:
+    "Render an HTML template from Responses (kind: template) with Mustache and return html + plain-text fallback",
+  config: {
+    template: {
+      type: "string",
+      required: true,
+      description: "Responses page name with kind=template",
+    },
+    partials: {
+      type: "object",
+      required: false,
+      description: "Map of partial name to template page name (e.g. { item: email-item })",
+    },
+  },
+  input: {
+    vars: {
+      type: "object",
+      required: true,
+      description: "Mustache view data (title, items, etc.)",
+    },
+  },
+  output: {
+    html: { type: "string", description: "Rendered HTML" },
+    text: { type: "string", description: "Plain-text fallback stripped from HTML" },
+    template: { type: "string", description: "Template page name used" },
+  },
+  example: {
+    data: {
+      vars: {
+        title: "Daily digest",
+        message: "Latest items from your feed.",
+        items: [
+          {
+            title: "Example post",
+            link: "https://example.com/post",
+            summary: "A short summary.",
+          },
+        ],
+      },
+    },
+    config: {
+      template: "email-default",
+    },
+  },
+};
+
+export default renderTemplate;

packages/server/scripts/send-email.js

@@ -147,8 +147,11 @@ async function sendEmail(ctx) {
   }
 
   const text = ctx.data?.text ?? ctx.data?.body ?? ctx.data?.message;
-  if (typeof text !== "string" || text.length === 0) {
-    throw new Error("data.text is required (plain-text body)");
+  const html = ctx.data?.html;
+  const hasText = typeof text === "string" && text.length > 0;
+  const hasHtml = typeof html === "string" && html.length > 0;
+  if (!hasText && !hasHtml) {
+    throw new Error("data.text or data.html is required");
   }
 
   const cc = normalizeRecipients(ctx.data?.cc, "data.cc");
@@ -174,8 +177,9 @@ async function sendEmail(ctx) {
     from,
     to,
     subject,
-    text,
   };
+  if (hasText) mail.text = text;
+  if (hasHtml) mail.html = html;
   if (cc) mail.cc = cc;
   if (bcc) mail.bcc = bcc;
   if (replyTo) mail.replyTo = replyTo;
@@ -203,9 +207,10 @@ async function sendEmail(ctx) {
       cc: cc ?? null,
       bcc: bcc ? "[redacted]" : null,
       subjectLength: subject.length,
-      textLength: text.length,
+      textLength: hasText ? text.length : 0,
+      htmlLength: hasHtml ? html.length : 0,
     },
-    "send-email: sending plain-text message",
+    "send-email: sending message",
   );
 
   const info = await transporter.sendMail(mail);
@@ -224,7 +229,7 @@ async function sendEmail(ctx) {
 }
 
 sendEmail.meta = {
-  description: "Send a plain-text email via SMTP (nodemailer)",
+  description: "Send an email via SMTP (nodemailer); plain text, HTML, or both",
   config: {
     service: {
       type: "string",
@@ -387,9 +392,14 @@ sendEmail.meta = {
     subject: { type: "string", required: true, description: "Email subject" },
     text: {
       type: "string",
-      required: true,
+      required: false,
       description: "Plain-text body (aliases: body, message)",
     },
+    html: {
+      type: "string",
+      required: false,
+      description: "HTML body (e.g. from render-template.js)",
+    },
     priority: {
       type: "string",
       required: false,