refactor: use optional chaining (#6757)

src/rest/APIRequest.js

@@ -48,7 +48,7 @@ class APIRequest {
     if (this.options.headers) headers = Object.assign(headers, this.options.headers);
 
     let body;
-    if (this.options.files && this.options.files.length) {
+    if (this.options.files?.length) {
       body = new FormData();
       for (const file of this.options.files) {
         if (file?.file) body.append(file.key ?? file.name, file.file, file.name);

src/rest/RequestHandler.js

@@ -177,7 +177,7 @@ class RequestHandler {
     }
 
     let sublimitTimeout;
-    if (res && res.headers) {
+    if (res.headers) {
       const serverDate = res.headers.get('date');
       const limit = res.headers.get('x-ratelimit-limit');
       const remaining = res.headers.get('x-ratelimit-remaining');

src/structures/Guild.js

@@ -926,7 +926,7 @@ class Guild extends AnonymousGuild {
     const welcome_channels = welcomeChannels?.map(welcomeChannelData => {
       const emoji = this.emojis.resolve(welcomeChannelData.emoji);
       return {
-        emoji_id: emoji && emoji.id,
+        emoji_id: emoji?.id,
         emoji_name: emoji?.name ?? welcomeChannelData.emoji,
         channel_id: this.channels.resolveId(welcomeChannelData.channel),
         description: welcomeChannelData.description,