Files
mail-tools/tests/core/mime.test.ts
T
2026-09-01 12:39:23 +02:00

95 lines
2.9 KiB
TypeScript

import { describe, expect, it } from "vitest";
import {
attachments,
decodeHeaderValue,
parseHeaders,
parseMessage,
walkParts,
} from "../../src/core/mime";
const MULTIPART = `From: =?UTF-8?Q?Ada_=E2=9C=93?= <ada@example.test>\r
Subject: folded\r
value\r
MIME-Version: 1.0\r
Content-Type: multipart/mixed; boundary="b"\r
\r
--b\r
Content-Type: text/plain; charset=utf-8\r
Content-Transfer-Encoding: quoted-printable\r
\r
hello=20world\r
--b\r
Content-Type: application/octet-stream\r
Content-Disposition: attachment; filename*=UTF-8''report%20one.txt\r
Content-Transfer-Encoding: base64\r
\r
YWJj\r
--b--`;
describe("MIME parser", () => {
it("unfolds fields and decodes RFC 2047 words", () => {
const headers = parseHeaders(
"Subject: =?UTF-8?Q?Hello_=E2=9C=93?=\r\n\tworld",
);
expect(headers[0]?.value).toBe("Hello ✓ world");
expect(decodeHeaderValue("=?ISO-8859-1?Q?Andr=E9?=")).toBe("André");
expect(decodeHeaderValue("=?UTF-8?Q?joined?= =?UTF-8?Q?_words?=")).toBe(
"joined words",
);
});
it("builds nested parts and decodes transfer encodings", () => {
const parsed = parseMessage(MULTIPART);
expect(walkParts(parsed.root).map((part) => part.mediaType)).toEqual([
"multipart/mixed",
"text/plain",
"application/octet-stream",
]);
expect(parsed.root.children[0]?.text).toBe("hello world");
expect([...parsed.root.children[1]!.bytes]).toEqual([97, 98, 99]);
expect(attachments(parsed.root)[0]).toMatchObject({
filename: "report one.txt",
size: 3,
});
});
it("parses nested message/rfc822 entities", () => {
const parsed = parseMessage(
"From: a@example.test\nContent-Type: message/rfc822\n\nFrom: b@example.test\nContent-Type: text/plain\n\nnested",
);
expect(parsed.root.children[0]?.text).toBe("nested");
});
it("decodes and exposes transferred message attachments", () => {
const nested = btoa(
"From: b@example.test\r\nContent-Type: text/plain\r\n\r\nnested",
);
const parsed = parseMessage(
`From: a@example.test\nContent-Type: message/rfc822; name="forwarded.eml"\nContent-Disposition: attachment; filename="forwarded.eml"\nContent-Transfer-Encoding: base64\n\n${nested}`,
);
expect(parsed.root.children[0]?.text).toBe("nested");
expect(attachments(parsed.root)[0]).toMatchObject({
filename: "forwarded.eml",
});
expect(attachments(parsed.root)[0]?.size).toBeGreaterThan(0);
});
it("fails closed for malformed and excessive structures", () => {
expect(() => parseMessage("Bad header\n\nbody")).toThrow(
/malformed header/iu,
);
expect(() =>
parseMessage("Content-Type: multipart/mixed; boundary=x\n\nnone"),
).toThrow(/boundary/iu);
expect(() =>
parseMessage("From: a@example.test\n\n12345", {
maxChars: 4,
maxHeaders: 2,
maxParts: 2,
maxDepth: 2,
maxDecodedBytes: 8,
}),
).toThrow(/limit/iu);
});
});