Initial commit

src/rest/DiscordAPIError.js

@@ -0,0 +1,82 @@
+'use strict';
+
+/**
+ * Represents an error from the Discord API.
+ * @extends Error
+ */
+class DiscordAPIError extends Error {
+  constructor(error, status, request) {
+    super();
+    const flattened = this.constructor.flattenErrors(error.errors ?? error).join('\n');
+    this.name = 'DiscordAPIError';
+    this.message = error.message && flattened ? `${error.message}\n${flattened}` : error.message ?? flattened;
+
+    /**
+     * The HTTP method used for the request
+     * @type {string}
+     */
+    this.method = request.method;
+
+    /**
+     * The path of the request relative to the HTTP endpoint
+     * @type {string}
+     */
+    this.path = request.path;
+
+    /**
+     * HTTP error code returned by Discord
+     * @type {number}
+     */
+    this.code = error.code;
+
+    /**
+     * The HTTP status code
+     * @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 ?? [],
+    };
+  }
+
+  /**
+   * Flattens an errors object returned from the API into an array.
+   * @param {APIError} obj Discord errors object
+   * @param {string} [key] Used internally to determine key names of nested fields
+   * @returns {string[]}
+   * @private
+   */
+  static flattenErrors(obj, key = '') {
+    let messages = [];
+
+    for (const [k, v] of Object.entries(obj)) {
+      if (k === 'message') continue;
+      const newKey = key ? (isNaN(k) ? `${key}.${k}` : `${key}[${k}]`) : k;
+
+      if (v._errors) {
+        messages.push(`${newKey}: ${v._errors.map(e => e.message).join(' ')}`);
+      } else if (v.code ?? v.message) {
+        messages.push(`${v.code ? `${v.code}: ` : ''}${v.message}`.trim());
+      } else if (typeof v === 'string') {
+        messages.push(v);
+      } else {
+        messages = messages.concat(this.flattenErrors(v, newKey));
+      }
+    }
+
+    return messages;
+  }
+}
+
+module.exports = DiscordAPIError;
+
+/**
+ * @external APIError
+ * @see {@link https://discord.com/developers/docs/reference#error-messages}
+ */