smtp: reduce usage of nullish coalescing operator

smtp/address.ts

@@ -147,7 +147,7 @@ function convertAddressTokens(tokens: AddressToken[]) {
 			if (addresses.length === 0) {
 				for (let i = texts.length - 1; i >= 0; i--) {
 					const text = texts[i];
-					if (text?.length > 0) {
+					if (text != null && text.length > 0) {
 						texts[i] = text
 							.replace(/\s*\b[^@\s]+@[^@\s]+\b\s*/, (address: string) => {
 								if (addresses.length === 0) {

smtp/client.ts

@@ -148,8 +148,8 @@ export class SMTPClient {
 		if (typeof returnPath === 'string' && returnPath.length > 0) {
 			const parsedAddresses = addressparser(returnPath);
 			if (parsedAddresses.length > 0) {
-				const [firstParsedAddress] = parsedAddresses;
-				stack.returnPath = firstParsedAddress?.address ?? '';
+				const [{ address = '' } = {}] = parsedAddresses;
+				stack.returnPath = address;
 			}
 		}
 

smtp/date.ts

@@ -8,19 +8,13 @@ export function getRFC2822Date(date = new Date(), useUtc = false) {
 		return getRFC2822DateUTC(date);
 	}
 
-	const dates = date
+	const [zero, one, two, ...rest] = date
 		.toString()
 		.replace('GMT', '')
 		.replace(/\s\(.*\)$/, '')
 		.split(' ');
 
-	dates[0] = dates[0] + ',';
-
-	const day = dates[1] ?? '';
-	dates[1] = dates[2] ?? '';
-	dates[2] = day;
-
-	return dates.join(' ');
+	return [zero + ',', two, one, ...rest].join(' ');
 }
 
 /**

smtp/message.ts

@@ -163,7 +163,7 @@ export class Message {
 					headers[header] as string | string[]
 				);
 			} else {
-				// allow any headers the user wants to set??
+				// allow any headers the user wants to set
 				this.header[header.toLowerCase()] = headers[header];
 			}
 		}
@@ -589,10 +589,9 @@ class MessageStream extends Stream {
 			attachment: MessageAttachment,
 			callback: () => void
 		) => {
+			const { data = '' } = attachment;
 			outputBase64(
-				attachment.encoded
-					? attachment.data ?? ''
-					: Buffer.from(attachment.data ?? '').toString('base64'),
+				attachment.encoded ? data : Buffer.from(data).toString('base64'),
 				callback
 			);
 		};

smtp/mime.ts

@@ -21,8 +21,9 @@ const MAX_B64_MIME_WORD_BYTE_LENGTH = 39;
 
 function tripletToBase64(num: number) {
 	return (
-		(LOOKUP[(num >> 18) & 0x3f] ?? '') +
-		(LOOKUP[(num >> 12) & 0x3f] ?? '') +
+		'' +
+		LOOKUP[(num >> 18) & 0x3f] +
+		LOOKUP[(num >> 12) & 0x3f] +
 		LOOKUP[(num >> 6) & 0x3f] +
 		LOOKUP[num & 0x3f]
 	);
@@ -32,7 +33,9 @@ function encodeChunk(uint8: Uint8Array, start: number, end: number) {
 	let output = '';
 	for (let i = start; i < end; i += 3) {
 		output += tripletToBase64(
-			((uint8[i] ?? 0) << 16) + ((uint8[i + 1] ?? 0) << 8) + (uint8[i + 2] ?? 0)
+			(Number(uint8[i]) << 16) +
+				(Number(uint8[i + 1]) << 8) +
+				Number(uint8[i + 2])
 		);
 	}
 	return output;
@@ -54,12 +57,12 @@ function encodeBase64(data: Uint8Array) {
 
 	// pad the end with zeros, but make sure to not forget the extra bytes
 	if (extraBytes === 1) {
-		const tmp = data[len - 1] ?? 0;
+		const tmp = Number(data[len - 1]);
 		output += LOOKUP[tmp >> 2];
 		output += LOOKUP[(tmp << 4) & 0x3f];
 		output += '==';
 	} else if (extraBytes === 2) {
-		const tmp = ((data[len - 2] ?? 0) << 8) + (data[len - 1] ?? 0);
+		const tmp = (Number(data[len - 2]) << 8) + Number(data[len - 1]);
 		output += LOOKUP[tmp >> 10];
 		output += LOOKUP[(tmp >> 4) & 0x3f];
 		output += LOOKUP[(tmp << 2) & 0x3f];
@@ -93,9 +96,10 @@ function splitMimeEncodedString(str: string, maxlen = 12) {
 		while (!done) {
 			let chr;
 			done = true;
-			const match = str.substring(curLine.length).match(/^=([0-9A-F]{2})/i); // check if not middle of a unicode char sequence
-			if (match) {
-				chr = parseInt(match[1] ?? '', 16);
+			const matchset = str.substring(curLine.length).match(/^=([0-9A-F]{2})/i); // check if not middle of a unicode char sequence
+			if (matchset != null) {
+				const [, secondMatch = ''] = matchset;
+				chr = parseInt(secondMatch, 16);
 				// invalid sequence, move one char back anc recheck
 				if (chr < 0xc2 && chr > 0x7f) {
 					curLine = curLine.substring(0, curLine.length - 3);