Nodemailer 10 support

.github/workflows/test.yml

@@ -9,7 +9,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v3
         with:
-          node-version: 18.12.1
+          node-version: 20.20.2
           cache: 'yarn'
       - run: yarn install --frozen-lockfile
       - run: yarn lint

.tool-versions

@@ -1,2 +1,2 @@
-nodejs 18.12.1
+nodejs 20.20.2
 yarn 1.22.17

README.md

@@ -198,7 +198,7 @@ mailtrap
 
 ## Nodemailer Transport
 
-> NOTE: [Nodemailer](https://www.npmjs.com/package/nodemailer) is needed as a dependency.
+> NOTE: [Nodemailer](https://www.npmjs.com/package/nodemailer) is needed as a dependency. Versions 9 and 10 are supported (Nodemailer 10 requires Node.js 20 or newer).
 
 ```sh
 npm install nodemailer
@@ -207,7 +207,7 @@ npm install nodemailer
 yarn add nodemailer
 ```
 
-If you're using TypeScript, install `@types/nodemailer` as a `devDependency`:
+If you're using TypeScript with Nodemailer 9, install `@types/nodemailer` as a `devDependency` (Nodemailer 10 ships its own type definitions, so this is not needed there):
 
 ```sh
 npm install -D @types/nodemailer

package.json

@@ -27,7 +27,7 @@
     "eslint-plugin-import": "^2.29.1",
     "eslint-plugin-prettier": "^4.0.0",
     "jest": "^29.3.1",
-    "nodemailer": "^9.0.1",
+    "nodemailer": "^10.0.0",
     "prettier": "^2.6.2",
     "rimraf": "^5.0.5",
     "ts-node": "^10.2.1",
@@ -48,7 +48,7 @@
   },
   "peerDependencies": {
     "@types/nodemailer": "^6.4.9",
-    "nodemailer": "^9.0.1"
+    "nodemailer": "^9.0.1 || ^10.0.0"
   },
   "peerDependenciesMeta": {
     "nodemailer": {
@@ -60,7 +60,7 @@
   },
   "repository": "https://github.com/railsware/mailtrap-nodejs",
   "scripts": {
-    "build": "rimraf dist && tsc --project tsconfig.build.json",
+    "build": "rimraf dist && tsc --project tsconfig.build.json && rimraf dist/lib/transport-esm.mjs",
     "lint": "yarn lint:eslint && yarn lint:tsc",
     "lint:eslint": "yarn run eslint . --ext .js,.ts",
     "lint:tsc": "tsc -p . --noEmit --incremental false",

src/__tests__/adapters/attachment.test.ts

@@ -45,33 +45,27 @@ describe("adapters/attachment: ", () => {
       expect(result).toEqual(expectedAttachment);
     });
 
-    it("returns adapted attachment object in case if content is readable.", () => {
-      const content = "mock-content";
+    it("throws `content required` error for content nodemailer did not resolve.", () => {
       const readableStream = new Readable({
         read() {
-          this.push(content);
+          this.push("mock-content");
           this.push(null);
         },
       });
 
-      const attachment = {
-        filename: "mock-filename",
-        content: readableStream,
-      };
-
-      const expectedAttachment = {
-        filename: attachment.filename,
-        disposition: undefined,
-        content_id: undefined,
-        type: undefined,
-      };
-      const result = adaptAttachment(attachment);
-
-      expect(result.filename).toEqual(expectedAttachment.filename);
-      expect(result.disposition).toEqual(expectedAttachment.disposition);
-      expect(result.content_id).toEqual(expectedAttachment.content_id);
-      expect(result.type).toEqual(expectedAttachment.type);
-      expect(result.content.toString()).toEqual(content);
+      const unresolvedContents = [
+        "",
+        readableStream,
+        { path: __filename },
+        { content: { path: __filename } },
+        { filename: "mock-filename", content: "", contentType: "text/plain" },
+      ];
+
+      unresolvedContents.forEach((content) => {
+        expect(() =>
+          adaptAttachment({ filename: "mock-filename", content })
+        ).toThrowError(new Error(CONTENT_REQUIRED));
+      });
     });
 
     it("returns adapted attachment object.", () => {

src/__tests__/adapters/content.test.ts

@@ -1,9 +1,11 @@
 import { Readable } from "stream";
-import fs from "node:fs";
 
 import adaptContent from "../../adapters/content";
 
-jest.mock("node:fs");
+import config from "../../config";
+
+const { ERRORS } = config;
+const { CONTENT_REQUIRED } = ERRORS;
 
 describe("adapters/content: ", () => {
   describe("adaptContent(): ", () => {
@@ -23,39 +25,29 @@ describe("adapters/content: ", () => {
       expect(result).toBe(content);
     });
 
-    it("checks if read method has been called if content is readable.", () => {
-      const content = "mock-content";
+    it("throws `content required` error for content nodemailer did not resolve.", () => {
       const readableStream = new Readable({
         read() {
-          this.push(content);
+          this.push("mock-content");
           this.push(null);
         },
       });
 
-      const result = adaptContent(readableStream);
-
-      expect(result.toString()).toEqual(content);
-    });
-
-    it("recursively checks the content if content has content property.", () => {
-      const content = {
-        content: "mock-content",
-      };
-
-      const result = adaptContent(content);
-
-      expect(result).toBe(content.content);
-    });
-
-    it("reads file in case if content is file and has path.", () => {
-      const content = {
-        path: "mock-path",
-      };
-
-      adaptContent(content);
-
-      expect(fs.readFileSync).toBeCalledTimes(1);
-      expect(fs.readFileSync).toBeCalledWith(content.path);
+      const unresolvedContents = [
+        undefined,
+        "",
+        readableStream,
+        { path: __filename },
+        { content: "mock-content" },
+        { content: { path: __filename } },
+        { content: { content: { path: __filename } } },
+      ];
+
+      unresolvedContents.forEach((content) => {
+        expect(() => adaptContent(content)).toThrowError(
+          new Error(CONTENT_REQUIRED)
+        );
+      });
     });
   });
 });

src/__tests__/adapters/headers.test.ts

@@ -61,5 +61,143 @@ describe("adapters/headers: ", () => {
 
       expect(result).toEqual(expectedResult);
     });
+
+    it("returns object if headers is a single `{ key, value }` pair.", () => {
+      const headers = {
+        key: "mock-key",
+        value: "mock-value",
+      };
+
+      const expectedResult = {
+        [headers.key]: headers.value,
+      };
+      const result = adaptHeaders(headers);
+
+      expect(result).toEqual(expectedResult);
+    });
+
+    it("reads `{ key, value }` as a pair only when both are set.", () => {
+      expect(adaptHeaders({ key: "X-Custom", value: "mock-value" })).toEqual({
+        "X-Custom": "mock-value",
+      });
+      expect(adaptHeaders({ key: "", value: "mock-value" })).toEqual({
+        value: "mock-value",
+      });
+      expect(adaptHeaders({ key: "X-Count", value: 0 })).toEqual({
+        key: "X-Count",
+      });
+      expect(adaptHeaders({ key: "X-Only" })).toEqual({ key: "X-Only" });
+      expect(adaptHeaders({ value: "mock-value" })).toEqual({
+        value: "mock-value",
+      });
+    });
+
+    it("skips headers with a blank name.", () => {
+      expect(adaptHeaders({ key: "   ", value: "mock-value" })).toEqual({});
+      expect(
+        adaptHeaders([
+          { key: "X-One", value: "mock-value" },
+          { key: "", value: "mock-other-value" },
+        ])
+      ).toEqual({ "X-One": "mock-value" });
+    });
+
+    it("trims header names, as nodemailer does.", () => {
+      expect(adaptHeaders({ "  X-One  ": "mock-value" })).toEqual({
+        "X-One": "mock-value",
+      });
+      expect(
+        adaptHeaders([{ key: " X-Two ", value: "mock-other-value" }])
+      ).toEqual({ "X-Two": "mock-other-value" });
+    });
+
+    it("skips a value that refers to itself.", () => {
+      const selfReferencing: { value?: unknown } = {};
+      selfReferencing.value = selfReferencing;
+
+      expect(adaptHeaders({ mockKey: selfReferencing })).toEqual({});
+    });
+
+    it("converts non-string header values to strings.", () => {
+      const headers = {
+        mockNumber: 42,
+        mockBoolean: true,
+        mockAddress: { name: "mockname", address: "mock@mail.com" },
+        mockAddressWithoutName: { address: "mock@mail.com" },
+        mockNested: [[{ prepared: true, value: 7 }]],
+      };
+
+      const expectedResult = {
+        mockNumber: "42",
+        mockBoolean: "true",
+        mockAddress: "mockname <mock@mail.com>",
+        mockAddressWithoutName: "mock@mail.com",
+        mockNested: "7",
+      };
+      const result = adaptHeaders(headers);
+
+      expect(result).toEqual(expectedResult);
+    });
+
+    it("quotes display names nodemailer would not leave as they are.", () => {
+      const headers = {
+        mockPlain: { name: "John Doe", address: "j@mail.com" },
+        mockComma: { name: "Doe, John", address: "j@mail.com" },
+        mockQuote: { name: 'He said "hi"', address: "j@mail.com" },
+        mockBackslash: { name: "back\\slash", address: "j@mail.com" },
+        mockUnicode: { name: "Ünïcode", address: "j@mail.com" },
+      };
+
+      const expectedResult = {
+        mockPlain: "John Doe <j@mail.com>",
+        mockComma: '"Doe, John" <j@mail.com>',
+        mockQuote: '"He said \\"hi\\"" <j@mail.com>',
+        mockBackslash: '"back\\\\slash" <j@mail.com>',
+        mockUnicode: '"Ünïcode" <j@mail.com>',
+      };
+      const result = adaptHeaders(headers);
+
+      expect(result).toEqual(expectedResult);
+    });
+
+    it("replaces line breaks in header values.", () => {
+      const headers = {
+        mockInjection: "mock-value\r\nInjected: yes",
+        mockAddress: {
+          name: "Eve\r\nBcc: victim@mail.com",
+          address: "j@mail.com",
+        },
+      };
+
+      const expectedResult = {
+        mockInjection: "mock-value Injected: yes",
+        mockAddress: '"Eve Bcc: victim@mail.com" <j@mail.com>',
+      };
+      const result = adaptHeaders(headers);
+
+      expect(result).toEqual(expectedResult);
+    });
+
+    it("skips headers with empty values.", () => {
+      const headers = {
+        mockNull: null,
+        mockUndefined: undefined,
+        mockEmptyArray: [],
+        mockFalse: false,
+        mockZero: 0,
+        mockBlank: "   ",
+        mockDate: new Date("2026-01-02T03:04:05Z"),
+        mockAddressWithoutAddress: { name: "mock-name" },
+        mockAddressWithBlankAddress: { name: "mock-name", address: "  " },
+        mockKey: "mock-value",
+      };
+
+      const expectedResult = {
+        mockKey: "mock-value",
+      };
+      const result = adaptHeaders(headers);
+
+      expect(result).toEqual(expectedResult);
+    });
   });
 });

src/__tests__/adapters/mail.test.ts

@@ -3,7 +3,7 @@ import adaptMail from "../../adapters/mail";
 import config from "../../config";
 import {
   adaptSingleRecipient,
-  adaptReplyToRecipient,
+  adaptFirstRecipient,
 } from "../../adapters/recipients";
 
 const { ERRORS } = config;
@@ -20,6 +20,17 @@ describe("adapters/mail: ", () => {
       expect(result).toEqual(expectedResult);
     });
 
+    it("returns object with error `from is required` if from has no address.", () => {
+      const expectedResult = { success: false, errors: [FROM_REQUIRED] };
+
+      expect(adaptMail({ from: "" })).toEqual(expectedResult);
+      expect(adaptMail({ from: [] })).toEqual(expectedResult);
+      expect(adaptMail({ from: { address: "" } })).toEqual(expectedResult);
+      expect(adaptMail({ from: { name: "mock-name" } })).toEqual(
+        expectedResult
+      );
+    });
+
     it("returns `mail` object with basic info + headers.", () => {
       const data = {
         from: "mock-from",
@@ -37,7 +48,7 @@ describe("adapters/mail: ", () => {
         bcc: [],
         headers: data.headers,
         subject: data.subject,
-        reply_to: adaptReplyToRecipient(data.replyTo),
+        reply_to: adaptFirstRecipient(data.replyTo),
       };
       const result = adaptMail(data);
 
@@ -63,7 +74,7 @@ describe("adapters/mail: ", () => {
         bcc: [],
         headers: data.headers,
         attachments: data.attachments,
-        reply_to: adaptReplyToRecipient(data.replyTo),
+        reply_to: adaptFirstRecipient(data.replyTo),
       };
       const result = adaptMail(data);
 
@@ -93,7 +104,7 @@ describe("adapters/mail: ", () => {
         headers: data.headers,
         attachments: data.attachments,
         custom_variables: data.customVariables,
-        reply_to: adaptReplyToRecipient(data.replyTo),
+        reply_to: adaptFirstRecipient(data.replyTo),
       };
       const result = adaptMail(data);