feat(Rest): show the data that is sent to Discord when an errors occurs (#5701)

src/rest/DiscordAPIError.js

@@ -5,7 +5,7 @@
  * @extends Error
  */
 class DiscordAPIError extends Error {
-  constructor(path, error, method, status) {
+  constructor(error, status, request) {
     super();
     const flattened = this.constructor.flattenErrors(error.errors || error).join('\n');
     this.name = 'DiscordAPIError';
@@ -15,13 +15,13 @@ class DiscordAPIError extends Error {
      * The HTTP method used for the request
      * @type {string}
      */
-    this.method = method;
+    this.method = request.method;
 
     /**
      * The path of the request relative to the HTTP endpoint
      * @type {string}
      */
-    this.path = path;
+    this.path = request.path;
 
     /**
      * HTTP error code returned by Discord
@@ -34,6 +34,15 @@ class DiscordAPIError extends Error {
      * @type {number}
      */
     this.httpStatus = status;
+
+    /**
+     * The data associated with the request that caused this error
+     * @type {HTTPErrorData}
+     */
+    this.requestData = {
+      json: request.options.data,
+      files: request.options.files ?? [],
+    };
   }
 
   /**

src/rest/HTTPError.js

@@ -5,7 +5,7 @@
  * @extends Error
  */
 class HTTPError extends Error {
-  constructor(message, name, code, method, path) {
+  constructor(message, name, code, request) {
     super(message);
 
     /**
@@ -24,13 +24,36 @@ class HTTPError extends Error {
      * The HTTP method used for the request
      * @type {string}
      */
-    this.method = method;
+    this.method = request.method;
 
     /**
      * The path of the request relative to the HTTP endpoint
      * @type {string}
      */
-    this.path = path;
+    this.path = request.path;
+
+    /**
+     * The HTTP data that was sent to Discord
+     * @typedef {Object} HTTPErrorData
+     * @property {*} json The JSON data that was sent
+     * @property {HTTPAttachmentData[]} files The files that were sent with this request, if any
+     */
+
+    /**
+     * The attachment data that is sent to Discord
+     * @typedef {Object} HTTPAttachmentData
+     * @property {string} name The file name
+     * @property {Buffer} file The file buffer
+     */
+
+    /**
+     * The data associated with the request that caused this error
+     * @type {HTTPErrorData}
+     */
+    this.requestData = {
+      json: request.options.data,
+      files: request.options.files ?? [],
+    };
   }
 }
 

src/rest/RequestHandler.js

@@ -143,7 +143,7 @@ class RequestHandler {
     } catch (error) {
       // Retry the specified number of times for request abortions
       if (request.retries === this.manager.client.options.retryLimit) {
-        throw new HTTPError(error.message, error.constructor.name, error.status, request.method, request.path);
+        throw new HTTPError(error.message, error.constructor.name, error.status, request);
       }
 
       request.retries++;
@@ -237,17 +237,17 @@ class RequestHandler {
       try {
         data = await parseResponse(res);
       } catch (err) {
-        throw new HTTPError(err.message, err.constructor.name, err.status, request.method, request.path);
+        throw new HTTPError(err.message, err.constructor.name, err.status, request);
       }
 
-      throw new DiscordAPIError(request.path, data, request.method, res.status);
+      throw new DiscordAPIError(data, res.status, request);
     }
 
     // Handle 5xx responses
     if (res.status >= 500 && res.status < 600) {
       // Retry the specified number of times for possible serverside issues
       if (request.retries === this.manager.client.options.retryLimit) {
-        throw new HTTPError(res.statusText, res.constructor.name, res.status, request.method, request.path);
+        throw new HTTPError(res.statusText, res.constructor.name, res.status, request);
       }
 
       request.retries++;

src/structures/APIMessage.js

@@ -125,6 +125,9 @@ class APIMessage {
    */
   resolveData() {
     if (this.data) return this;
+    const isInteraction = this.isInteraction;
+    const isWebhook = this.isWebhook;
+    const isWebhookLike = isInteraction || isWebhook;
 
     const content = this.makeContent();
     const tts = Boolean(this.options.tts);
@@ -139,7 +142,7 @@ class APIMessage {
     }
 
     const embedLikes = [];
-    if (this.isInteraction || this.isWebhook) {
+    if (isWebhookLike) {
       if (this.options.embeds) {
         embedLikes.push(...this.options.embeds);
       }
@@ -150,7 +153,7 @@ class APIMessage {
 
     let username;
     let avatarURL;
-    if (this.isWebhook) {
+    if (isWebhook) {
       username = this.options.username || this.target.name;
       if (this.options.avatarURL) avatarURL = this.options.avatarURL;
     }
@@ -159,7 +162,7 @@ class APIMessage {
     if (this.isMessage) {
       // eslint-disable-next-line eqeqeq
       flags = this.options.flags != null ? new MessageFlags(this.options.flags).bitfield : this.target.flags.bitfield;
-    } else if (this.isInteraction && this.options.ephemeral) {
+    } else if (isInteraction && this.options.ephemeral) {
       flags = MessageFlags.FLAGS.EPHEMERAL;
     }
 
@@ -191,8 +194,8 @@ class APIMessage {
       content,
       tts,
       nonce,
-      embed: this.options.embed === null ? null : embeds[0],
-      embeds,
+      embed: !isWebhookLike ? (this.options.embed === null ? null : embeds[0]) : undefined,
+      embeds: isWebhookLike ? embeds : undefined,
       username,
       avatar_url: avatarURL,
       allowed_mentions: