feat: announcement email with one-click unsubscribe headers

mail/announcement_test.go

@@ -0,0 +1,70 @@
+package mail
+
+import (
+	"strings"
+	"testing"
+)
+
+func sampleAnnouncement() Announcement {
+	return Announcement{
+		CategoryLabel:  "New features",
+		Subject:        "New in Vantage: scheduled workflows",
+		BodyMarkdown:   "Workflows can now run **on a schedule**.\n\n<script>alert(1)</script>\n\n- cron syntax\n- time zones",
+		UnsubscribeURL: "https://api.example/email/unsubscribe?c=features&t=abc",
+		PreferencesURL: "https://hq.example/email-preferences?t=abc",
+		PostalAddress:  "Hostxtra Ltd, 1 High Street, Leeds",
+	}
+}
+
+func TestRenderAnnouncement(t *testing.T) {
+	subject, html, text, err := RenderAnnouncement(sampleAnnouncement(), "https://hq.example")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if subject != "New in Vantage: scheduled workflows" {
+		t.Errorf("subject = %q", subject)
+	}
+	if !strings.Contains(html, "<strong>on a schedule</strong>") {
+		t.Error("markdown not rendered to html")
+	}
+	if strings.Contains(html, "<script>") {
+		t.Error("raw html from markdown reached the email")
+	}
+	for label, body := range map[string]string{"html": html, "text": text} {
+		for _, want := range []string{"email/unsubscribe?c=features", "email-preferences?t=abc", "New features", "Hostxtra Ltd"} {
+			if !strings.Contains(body, want) {
+				t.Errorf("%s body missing %q", label, want)
+			}
+		}
+		if strings.Contains(body, "—") {
+			t.Errorf("%s body contains an em dash", label)
+		}
+	}
+	if !strings.Contains(text, "**on a schedule**") {
+		t.Error("text part should carry the markdown source")
+	}
+}
+
+func TestRenderAnnouncementWithoutPostalAddress(t *testing.T) {
+	a := sampleAnnouncement()
+	a.PostalAddress = ""
+	_, html, _, err := RenderAnnouncement(a, "")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Contains(html, "<no value>") {
+		t.Error("empty postal address rendered as <no value>")
+	}
+}
+
+func TestSendAnnouncementRefusesListsAndMissingLink(t *testing.T) {
+	s := Sender{Host: "smtp.invalid", From: "updates@example.com"}
+	if err := s.SendAnnouncement("a@example.com, b@example.com", sampleAnnouncement()); err == nil {
+		t.Error("a comma-separated To must be refused")
+	}
+	a := sampleAnnouncement()
+	a.UnsubscribeURL = ""
+	if err := s.SendAnnouncement("a@example.com", a); err == nil {
+		t.Error("an announcement without an unsubscribe URL must be refused")
+	}
+}