feat(help): add mentor assignment email notification

.env.example

@@ -28,6 +28,10 @@ KV_REST_API_READ_ONLY_TOKEN=
 INNGEST_EVENT_KEY=
 INNGEST_SIGNING_KEY=
 
+# Email
+RESEND_API_KEY=
+EMAIL_FROM=onboarding@resend.dev
+
 # Groq (LLM)
 GROQ_API_KEY=
 GROQ_BUDGET_PER_DAY=400000

src/inngest/functions/help-dispatch.ts

@@ -1,6 +1,7 @@
 import { inngest } from '../client';
 import { getServiceSupabase } from '@/lib/supabase/service';
 import { rankReviewers, type ReviewerCandidate } from '@/lib/help/dispatch';
+import { sendHelpDispatchEmail } from '@/lib/email';
 
 /**
  * Help dispatch: when a user fires a help request, fan out notifications to
@@ -25,7 +26,7 @@ export const helpDispatch = inngest.createFunction(
 
       const { data: mentee } = await sb
         .from('profiles')
-        .select('level, primary_language')
+        .select('level, primary_language, github_handle')
         .eq('id', userId)
         .maybeSingle();
       const menteeLevel = mentee?.level ?? 0;
@@ -42,7 +43,7 @@ export const helpDispatch = inngest.createFunction(
       // Pool: all L2+ profiles. In production we'd narrow by recent activity etc.
       const { data: pool } = await sb
         .from('profiles')
-        .select('id, level, primary_language')
+        .select('id, level, primary_language, github_handle, email')
         .gte('level', 2)
         .neq('id', userId);
 
@@ -68,6 +69,12 @@ export const helpDispatch = inngest.createFunction(
 
       if (targets.length === 0) return { notified: 0 };
 
+      const { data: helpRequest } = await sb
+        .from('help_requests')
+        .select('reason, pr_url')
+        .eq('id', helpRequestId)
+        .maybeSingle();
+
       // Write a notification row per target for the help-inbox to pick up.
       const rows = targets.map((t) => ({
         user_id: t.userId,
@@ -76,6 +83,24 @@ export const helpDispatch = inngest.createFunction(
       }));
       await sb.from('activity_log').insert(rows);
 
+      for (const target of targets) {
+        const mentor = pool?.find((p) => p.id === target.userId);
+
+        if (!mentor?.email) continue;
+
+        try {
+          await sendHelpDispatchEmail({
+            to: mentor.email,
+            mentorHandle: mentor.github_handle ?? 'mentor',
+            menteeHandle: mentee?.github_handle ?? 'contributor',
+            prUrl: helpRequest?.pr_url ?? '',
+            helpReason: helpRequest?.reason ?? null,
+          });
+        } catch (error) {
+          console.error('failed to send help dispatch email', error);
+        }
+      }
+
       return { notified: targets.length };
     });
 

src/lib/email.test.ts

@@ -0,0 +1,15 @@
+import { describe, expect, it } from 'vitest';
+import { sendHelpDispatchEmail } from './email';
+
+describe('sendHelpDispatchEmail', () => {
+  it('skips sending when resend is not configured', async () => {
+    const result = await sendHelpDispatchEmail({
+      to: 'test@example.com',
+      mentorHandle: 'mentor',
+      menteeHandle: 'mentee',
+      prUrl: 'https://github.com/test/pr/1',
+    });
+
+    expect(result).toEqual({ skipped: true });
+  });
+});

src/lib/email.ts

@@ -0,0 +1,59 @@
+import { Resend } from 'resend';
+
+type SendHelpDispatchEmailArgs = {
+  to: string;
+  mentorHandle: string;
+  menteeHandle: string;
+  prUrl: string;
+  helpReason?: string | null;
+};
+
+const resendApiKey = process.env.RESEND_API_KEY;
+
+const resend = resendApiKey ? new Resend(resendApiKey) : null;
+
+export async function sendHelpDispatchEmail({
+  to,
+  mentorHandle,
+  menteeHandle,
+  prUrl,
+  helpReason,
+}: SendHelpDispatchEmailArgs) {
+  if (!resend) {
+    console.warn('RESEND_API_KEY missing, skipping email send');
+    return { skipped: true };
+  }
+
+  return resend.emails.send({
+    from: process.env.EMAIL_FROM || 'onboarding@resend.dev',
+    to,
+    subject: '[MergeShip] Someone needs your help on a PR',
+    html: `
+      <h2>Someone needs your help on a PR</h2>
+
+      <p>Hello ${mentorHandle},</p>
+
+      <p>${menteeHandle} has requested help on a pull request.</p>
+
+      <p>
+        <strong>Pull Request:</strong><br />
+        <a href="${prUrl}">${prUrl}</a>
+      </p>
+
+      ${
+        helpReason
+          ? `
+        <p>
+          <strong>Help Request:</strong><br />
+          ${helpReason}
+        </p>
+      `
+          : ''
+      }
+
+      <p>
+        Visit the Help Inbox to respond and assist the contributor.
+      </p>
+    `,
+  });
+}