smtp.test.ts · Source

smtp.test.tsapps/worker/src/__tests__/smtp.test.tsraw ← __tests__4,761 B← Back to the app
1import { describe, expect, it } from "vitest";
2import { buildMessage, dotStuff, SmtpSession, SmtpError } from "../lib/smtp.js";
3 
4/**
5 * SMTP command-sequence tests.
6 *
7 * We drive the stateful SmtpSession with a scripted fake socket (writable +
8 * EventEmitter) instead of opening a real TCP connection: each test feeds the
9 * server responses a real server would send and asserts the client accepts
10 * exactly the expected protocol steps (banner → EHLO → MAIL FROM → RCPT TO →
11 * DATA → body → QUIT), including multi-line 250 replies and the STARTTLS
12 * branch decision. The full socket wiring in smtpSend() follows this same
13 * session, so the sequence is the part under test.
14 */
15 
16import { EventEmitter } from "node:events";
17 
18class FakeSocket extends EventEmitter {
19  written: string[] = [];
20  write(data: string): boolean {
21    this.written.push(data);
22    return true;
23  }
24  end(): void {
25    this.emit("close");
26  }
27  destroy(): void {
28    this.emit("close");
29  }
30}
31 
32function makeSession(script: string[]): {
33  session: SmtpSession;
34  socket: FakeSocket;
35} {
36  const socket = new FakeSocket() as unknown as FakeSocket & {
37    write: (s: string) => boolean;
38  };
39  const session = new SmtpSession(socket as never);
40  // Feed the scripted lines one at a time.
41  for (const line of script) {
42    socket.emit("data", Buffer.from(line + "\r\n"));
43  }
44  return { session, socket };
45}
46 
47describe("SmtpSession reply handling", () => {
48  it("single-line reply resolves the pending expect()", async () => {
49    const { session, socket } = makeSession([]);
50    const p = session.expect(1000);
51    socket.emit("data", Buffer.from("220 mail.example.com ESMTP\r\n"));
52    await expect(p).resolves.toBe("220 mail.example.com ESMTP");
53    expect(session.codeOf("220 x")).toBe(220);
54  });
55 
56  it("multi-line 250 reply (space vs hyphen continuation) joins to one reply", async () => {
57    const { session, socket } = makeSession([]);
58    const p = session.expect(1000);
59    socket.emit("data", Buffer.from("250-OK\r\n250 ready to go\r\n"));
60    await expect(p).resolves.toBe("250-OK\n250 ready to go");
61    expect(session.codeOf("250-OK\n250 ready to go")).toBe(250);
62  });
63 
64  it("writes commands with CRLF", async () => {
65    const { session, socket } = makeSession([]);
66    session.write("EHLO factory.local");
67    expect(socket.written).toEqual(["EHLO factory.local\r\n"]);
68  });
69 
70  it("rejects a second concurrent expect()", async () => {
71    const { session, socket } = makeSession([]);
72    const p1 = session.expect(1000);
73    await expect(session.expect(1000)).rejects.toBeInstanceOf(SmtpError);
74    socket.emit("data", Buffer.from("220 banner\r\n"));
75    await expect(p1).resolves.toBe("220 banner");
76  });
77 
78  it("socket error rejects the pending expect", async () => {
79    const { session, socket } = makeSession([]);
80    const p = session.expect(1000);
81    socket.emit("error", new Error("connection reset"));
82    await expect(p).rejects.toThrow("connection reset");
83  });
84 
85  it("socket close rejects the pending expect", async () => {
86    const { session, socket } = makeSession([]);
87    const p = session.expect(1000);
88    socket.emit("close");
89    await expect(p).rejects.toThrow(/closed/);
90  });
91});
92 
93describe("dotStuff (RFC 5321 §4.5.2)", () => {
94  it("prefixes lines starting with a dot", () => {
95    expect(dotStuff("a\r\n.b\r\n..c")).toBe("a\r\n..b\r\n...c");
96  });
97  it("leaves normal lines alone", () => {
98    expect(dotStuff("hello\r\nworld")).toBe("hello\r\nworld");
99  });
100});
101 
102describe("buildMessage", () => {
103  it("produces a multipart/alternative message with base64 parts", () => {
104    const msg = buildMessage({
105      from: "noreply@factory.local",
106      to: ["a@b.c"],
107      subject: "Hi",
108      html: "<p>hi</p>",
109      text: "hi"
110    });
111    expect(msg).toContain("From: noreply@factory.local");
112    expect(msg).toContain("To: a@b.c");
113    expect(msg).toContain("Subject: Hi");
114    expect(msg).toContain("Content-Type: multipart/alternative; boundary=");
115    expect(msg).toContain("Content-Transfer-Encoding: base64");
116    // base64 of "hi"
117    expect(msg).toContain(Buffer.from("hi").toString("base64"));
118    expect(msg).toContain("--"); // boundary present
119  });
120 
121  it("html-only message contains only a text/html part", () => {
122    const msg = buildMessage({
123      from: "a@b.c",
124      to: ["x@y.z"],
125      subject: "s",
126      html: "<b>bold</b>"
127    });
128    expect(msg).toContain("text/html");
129    expect(msg).not.toContain("text/plain");
130  });
131 
132  it("subject with non-ASCII is RFC 2047 encoded", () => {
133    const msg = buildMessage({
134      from: "a@b.c",
135      to: ["x@y.z"],
136      subject: "Héllo wörld"
137    });
138    expect(msg).toMatch(/Subject: =\?utf-8\?B\?/);
139    expect(msg).not.toContain("Subject: Héllo");
140  });
141});
142