strongly type functions

smtp/client.js

@@ -16,11 +16,12 @@ class Client {
 	 * @property {string[]} [authentication]
 	 *
 	 * @typedef {Object} MessageStack
-	 * @property {Function} [callback]
+	 * @property {function(Error, Message): void} [callback]
-	 * @property {Message} message
+	 * @property {Message} [message]
 	 * @property {string} [returnPath]
 	 * @property {string} [from]
-	 * @property {Array} [to]
+	 * @property {string} [subject]
+	 * @property {string|Array} [to]
 	 * @property {Array} [cc]
 	 * @property {Array} [bcc]
 	 * @property {string} [text]
@@ -122,7 +123,7 @@ class Client {
 
 	/**
 	 * @param {Message|MessageStack} msg msg
-	 * @param {Function} callback callback
+	 * @param {function(Error, MessageStack): void} callback callback
 	 * @returns {void}
 	 */
 	send(msg, callback) {
@@ -145,7 +146,8 @@ class Client {
 			msg instanceof Message ? msg : canMakeMessage(msg) ? create(msg) : null;
 
 		if (message == null) {
-			callback(new Error('message is not a valid Message instance'), msg);
+			// prettier-ignore
+			callback(new Error('message is not a valid Message instance'), /**@type {MessageStack}*/(msg));
 			return;
 		}
 
@@ -178,7 +180,8 @@ class Client {
 				this.queue.push(stack);
 				this._poll();
 			} else {
-				callback(new Error(why), msg);
+				// prettier-ignore
+				callback(new Error(why), /**@type {MessageStack}*/(msg));
 			}
 		});
 	}
@@ -211,8 +214,8 @@ class Client {
 
 	/**
 	 * @param {MessageStack} stack stack
-	 * @param {Function} next next
+	 * @param {function(MessageStack): void} next next
-	 * @returns {Function} callback
+	 * @returns {function(Error): void} callback
 	 */
 	_sendsmtp(stack, next) {
 		/**
@@ -245,7 +248,8 @@ class Client {
 	 * @returns {void}
 	 */
 	_sendrcpt(stack) {
-		const to = stack.to.shift().address;
+		//prettier-ignore
+		const to = /** @type{Array} */(stack.to).shift().address;
 		this.smtp.rcpt(
 			this._sendsmtp(stack, stack.to.length ? this._sendrcpt : this._senddata),
 			'<' + to + '>'

smtp/message.js

@@ -208,7 +208,7 @@ class Message {
 	}
 
 	/**
-	 * @param {Function} callback the function to call with the error and buffer
+	 * @param {function(Error, string): void} callback the function to call with the error and buffer
 	 * @returns {void}
 	 */
 	read(callback) {
@@ -298,7 +298,7 @@ class MessageStream extends Stream {
 		 * @param {string} boundary the boundary text between outputs
 		 * @param {MessageAttachment[]} list the list of potential messages to output
 		 * @param {number} index the index of the list item to output
-		 * @param {Function} callback the function to call if index is greater than upper bound
+		 * @param {function(): void} callback the function to call if index is greater than upper bound
 		 * @returns {void}
 		 */
 		const output_message = (boundary, list, index, callback) => {
@@ -353,15 +353,9 @@ class MessageStream extends Stream {
 			output(data.concat([CRLF]).join(''));
 		};
 
-		/**
-		 * @callback NextFn
-		 * @param {NodeJS.ErrnoException} err
-		 * @returns {void}
-		 */
-
 		/**
 		 * @param {MessageAttachment} attachment the metadata to use as headers
-		 * @param {NextFn} callback the function to call after output is finished
+		 * @param {function(): void} callback the function to call after output is finished
 		 * @returns {void}
 		 */
 		const output_attachment = (attachment, callback) => {
@@ -376,7 +370,7 @@ class MessageStream extends Stream {
 
 		/**
 		 * @param {MessageAttachment} attachment the metadata to use as headers
-		 * @param {Function} callback the function to call after output is finished
+		 * @param {function(): void} callback the function to call after output is finished
 		 * @returns {void}
 		 */
 		const output_data = (attachment, callback) => {
@@ -390,7 +384,7 @@ class MessageStream extends Stream {
 
 		/**
 		 * @param {MessageAttachment} attachment the metadata to use as headers
-		 * @param {NextFn} next the function to call when the file is closed
+		 * @param {function(NodeJS.ErrnoException): void} next the function to call when the file is closed
 		 * @returns {void}
 		 */
 		const output_file = (attachment, next) => {
@@ -399,7 +393,7 @@ class MessageStream extends Stream {
 			const closed = fd => fs.closeSync(fd);
 
 			/**
-			 * @param {*} err the error to emit
+			 * @param {Error} err the error to emit
 			 * @param {number} fd the file descriptor
 			 * @returns {void}
 			 */
@@ -449,7 +443,7 @@ class MessageStream extends Stream {
 
 		/**
 		 * @param {MessageAttachment} attachment the metadata to use as headers
-		 * @param {Function} callback the function to call after output is finished
+		 * @param {function(): void} callback the function to call after output is finished
 		 * @returns {void}
 		 */
 		const output_stream = (attachment, callback) => {
@@ -496,7 +490,7 @@ class MessageStream extends Stream {
 
 		/**
 		 * @param {string} data the data to output as base64
-		 * @param {Function} [callback] the function to call after output is finished
+		 * @param {function(): void} [callback] the function to call after output is finished
 		 * @returns {void}
 		 */
 		const output_base64 = (data, callback) => {
@@ -533,7 +527,7 @@ class MessageStream extends Stream {
 
 		/**
 		 * @param {Message} message the message to output
-		 * @param {Function} callback the function to call after output is finished
+		 * @param {function(): void} callback the function to call after output is finished
 		 * @returns {void}
 		 */
 		const output_alternative = (message, callback) => {
@@ -561,7 +555,7 @@ class MessageStream extends Stream {
 
 		/**
 		 * @param {MessageAttachment} message the message to output
-		 * @param {Function} callback the function to call after output is finished
+		 * @param {function(): void} callback the function to call after output is finished
 		 * @returns {void}
 		 */
 		const output_related = (message, callback) => {
@@ -618,7 +612,7 @@ class MessageStream extends Stream {
 
 		/**
 		 * @param {string} data the data to output
-		 * @param {Function} [callback] the function
+		 * @param {function(...args): void} [callback] the function
 		 * @param {*[]} [args] array of arguments to pass to the callback
 		 * @returns {void}
 		 */

smtp/response.js

@@ -6,7 +6,7 @@ class SMTPResponse {
 	 * @constructor
 	 * @param {NodeJS.Socket | TLSSocket} stream the open socket to stream a response from
 	 * @param {number} timeout the time to wait (in milliseconds) before closing the socket
-	 * @param {Function} onerror the function to call on error
+	 * @param {function(Error): void} onerror the function to call on error
 	 */
 	constructor(stream, timeout, onerror) {
 		let buffer = '';
@@ -132,7 +132,7 @@ exports.SMTPResponse = SMTPResponse;
 /**
  * @param {NodeJS.Socket | TLSSocket} stream the open socket to stream a response from
  * @param {number} timeout the time to wait (in milliseconds) before closing the socket
- * @param {Function} onerror the function to call on error
+ * @param {function(Error): void} onerror the function to call on error
  * @returns {SMTPResponse} the smtp response
  */
 exports.monitor = (stream, timeout, onerror) =>

test/server.js

@@ -3,18 +3,16 @@ const assert = require('assert');
 
 describe('Connect to wrong email server', function() {
 	const emailModulePath = require.resolve(path.join(__dirname, '..', 'email'));
-	let email;
 
 	beforeEach(function() {
 		if (require.cache[emailModulePath]) {
 			delete require.cache[emailModulePath];
 		}
-		email = require('../email');
 	});
 
 	it('Should not call callback multiple times with wrong server configuration', function(done) {
 		this.timeout(5000);
-		const server = email.server.connect({ host: 'bar.baz' });
+		const server = require(emailModulePath).server.connect({ host: 'bar.baz' });
 		server.send(
 			{
 				from: 'foo@bar.baz',