nutrition docker file fix

utils/mail_test.go

@@ -0,0 +1,158 @@
+package utils
+
+import (
+	"bufio"
+	"net"
+	"strings"
+	"testing"
+
+	"nearle/config"
+)
+
+/*
+Sending the invitation.
+
+These run against a fake SMTP server on a local port rather than a mock, because
+the thing worth testing is the conversation: Go's `net/smtp` decides on its own
+whether to hand over a password, and the question is what this code does when a
+relay does not offer encryption.
+*/
+
+// smtpStub answers just enough of the protocol to get to the interesting part.
+// `offerTLS` is the switch the tests turn.
+func smtpStub(t *testing.T, offerTLS bool) string {
+	t.Helper()
+
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+	t.Cleanup(func() { _ = listener.Close() })
+
+	go func() {
+		for {
+			conn, err := listener.Accept()
+			if err != nil {
+				return
+			}
+			go func() {
+				defer conn.Close()
+				reader := bufio.NewReader(conn)
+				write := func(line string) { _, _ = conn.Write([]byte(line + "\r\n")) }
+
+				write("220 stub ESMTP")
+				for {
+					line, err := reader.ReadString('\n')
+					if err != nil {
+						return
+					}
+					switch verb := strings.ToUpper(strings.TrimSpace(line)); {
+					case strings.HasPrefix(verb, "EHLO"):
+						write("250-stub")
+						if offerTLS {
+							write("250-STARTTLS")
+						}
+						write("250 AUTH PLAIN LOGIN")
+					case strings.HasPrefix(verb, "QUIT"):
+						write("221 bye")
+						return
+					default:
+						// Anything else is past the point these tests reach.
+						write("250 ok")
+					}
+				}
+			}()
+		}
+	}()
+
+	return listener.Addr().String()
+}
+
+func mailerFor(t *testing.T, address string, username string) Mailer {
+	t.Helper()
+
+	host, portText, err := net.SplitHostPort(address)
+	if err != nil {
+		t.Fatalf("splitting %q: %v", address, err)
+	}
+	port := 0
+	for _, digit := range portText {
+		port = port*10 + int(digit-'0')
+	}
+
+	mailer, err := NewMailer(config.MailConfig{
+		Host: host, Port: port,
+		Username:    username,
+		Password:    "a-password-that-must-not-cross-the-wire",
+		FromAddress: "care@nearledaily.com", FromName: "Nearle",
+		ConsoleURL: "https://app.nearledaily.com",
+	})
+	if err != nil {
+		t.Fatalf("building the mailer: %v", err)
+	}
+	if mailer == nil {
+		t.Fatal("no mailer from a configured sender")
+	}
+	return mailer
+}
+
+func TestAPasswordIsNeverSentToARelayWithNoTLS(t *testing.T) {
+	// The downgrade this guards. An attacker between us and the relay can strip
+	// STARTTLS from the greeting; "carry on unencrypted" is the wrong answer,
+	// and we are about to send a real Google app password.
+	mailer := mailerFor(t, smtpStub(t, false), "care@nearledaily.com")
+
+	err := mailer.Send("owner@rmart.example", "Set your Nearle password", "link")
+	if err == nil {
+		t.Fatal("sent credentials to a relay offering no encryption")
+	}
+	if !strings.Contains(err.Error(), "TLS") {
+		// The reason has to name the connection. Reported as a credential
+		// refusal it sends somebody to check the password, which is fine.
+		t.Errorf("the failure does not name the real problem: %v", err)
+	}
+	if strings.Contains(err.Error(), "a-password-that-must-not-cross-the-wire") {
+		t.Error("the password is in the error message")
+	}
+}
+
+func TestARelayWithNoCredentialsIsLeftAlone(t *testing.T) {
+	// A relay that authenticates by network rather than by password is usually
+	// a local MTA on the same host, where there is no wire to protect. It must
+	// not be refused for want of TLS it does not need.
+	mailer := mailerFor(t, smtpStub(t, false), "")
+
+	// The stub accepts the envelope and the body, so this gets past the point
+	// the guard above would have stopped at. Whether the stub completes the
+	// whole conversation is not the question — being refused for TLS is.
+	err := mailer.Send("owner@rmart.example", "Set your Nearle password", "link")
+	if err != nil && strings.Contains(err.Error(), "does not offer TLS") {
+		t.Fatalf("refused an unauthenticated relay over TLS: %v", err)
+	}
+}
+
+func TestAnUnconfiguredMailerIsNilRatherThanBroken(t *testing.T) {
+	// A deployment with no mail still boots and still onboards; the outcome
+	// says `invited: false` with the reason. See config.MailConfig.Why.
+	mailer, err := NewMailer(config.MailConfig{})
+	if err != nil {
+		t.Fatalf("an unconfigured mailer reported an error: %v", err)
+	}
+	if mailer != nil {
+		t.Fatal("built a mailer with no host")
+	}
+}
+
+func TestABadRecipientIsNamedRatherThanDialled(t *testing.T) {
+	// A merchant's primary email is typed by whoever onboarded them, so a typo
+	// is ordinary. It should be refused by name, before any connection.
+	mailer := mailerFor(t, smtpStub(t, true), "care@nearledaily.com")
+
+	err := mailer.Send("not an email", "Set your Nearle password", "link")
+	if err == nil {
+		t.Fatal("accepted an address that is not one")
+	}
+	if !strings.Contains(err.Error(), "not a valid email address") {
+		t.Errorf("unhelpful message: %v", err)
+	}
+}