Add TextBasedChannel{full}.getMessages()

src/client/rest/RESTMethods.js

@@ -292,6 +292,31 @@ class RESTMethods {
     });
   }
 
+  getChannelMessages(channel, payload = {}) {
+    return new Promise((resolve, reject) => {
+      const params = [];
+      if (payload.limit) {
+        params.push(`limit=${payload.limit}`);
+      }
+      if (payload.around) {
+        params.push(`around=${payload.around}`);
+      } else if (payload.before) {
+        params.push(`before=${payload.before}`);
+      } else if (payload.after) {
+        params.push(`after=${payload.after}`);
+      }
+
+      let request = Constants.Endpoints.channelMessages(channel.id);
+      if (params.length > 0) {
+        request += `?${params.join('&')}`;
+      }
+
+      this.rest.makeRequest('get', request, true)
+        .then(resolve)
+        .catch(reject);
+    });
+  }
+
   updateGuildRole(role, _data) {
     return new Promise((resolve, reject) => {
       /*

src/structures/DMChannel.js

@@ -49,6 +49,10 @@ class DMChannel extends Channel {
   _cacheMessage() {
     return;
   }
+
+  getMessages() {
+    return;
+  }
 }
 
 TextBasedChannel.applyToClass(DMChannel, true);

src/structures/GroupDMChannel.js

@@ -126,6 +126,9 @@ class GroupDMChannel extends Channel {
     return;
   }
 
+  getMessages() {
+    return;
+  }
 }
 
 TextBasedChannel.applyToClass(GroupDMChannel, true);

src/structures/TextChannel.js

@@ -34,6 +34,10 @@ class TextChannel extends GuildChannel {
   _cacheMessage() {
     return;
   }
+
+  getMessages() {
+    return;
+  }
 }
 
 TextBasedChannel.applyToClass(TextChannel, true);

src/structures/interface/TextBasedChannel.js

@@ -41,6 +41,44 @@ class TextBasedChannel {
     return this.client.rest.methods.sendMessage(this, content, true);
   }
 
+  /**
+   * The parameters to pass in when requesting previous messages from a channel. `around`, `before` and
+   * `after` are mutually exclusive. All the parameters are optional.
+   * ```js
+   * {
+   *  limit: 30, // the message limit, defaults to 50
+   *  before: '123', // gets messages before the given message ID
+   *  after: '123', // gets messages after the given message ID
+   *  around: '123', // gets messages around the given message ID
+   * }
+   * ```
+   * @typedef {Object} ChannelLogsQueryOptions
+   */
+
+  /**
+   * Gets the past messages sent in this channel. Resolves with a Collection mapping message ID's to Message objects.
+   * @param {ChannelLogsQueryOptions} [options={}] the query parameters to pass in
+   * @returns {Promise<Collection<String, Message>, Error>}
+   * @example
+   * // get messages
+   * channel.getMessages({limit: 10})
+   *  .then(messages => console.log(`Received ${messages.size} messages`))
+   *  .catch(console.log);
+   */
+  getMessages(options = {}) {
+    return new Promise((resolve, reject) => {
+      this.client.rest.methods.getChannelMessages(this, options)
+        .then(data => {
+          const messages = new Collection();
+          for (const message of data) {
+            messages.set(message.id, message);
+          }
+          resolve(messages);
+        })
+        .catch(reject);
+    });
+  }
+
   _cacheMessage(message) {
     const maxSize = this.client.options.max_message_cache;
     if (maxSize === 0) {
@@ -63,7 +101,11 @@ function applyProp(structure, prop) {
 }
 
 exports.applyToClass = (structure, full = false) => {
-  const props = full ? ['sendMessage', 'sendTTSMessage', '_cacheMessage'] : ['sendMessage', 'sendTTSMessage'];
+  const props = ['sendMessage', 'sendTTSMessage'];
+  if (full) {
+    props.push('_cacheMessage');
+    props.push('getMessages');
+  }
   for (const prop of props) {
     applyProp(structure, prop);
   }