Add GuildMember.addRole/addRoles (#615)

* Add GuildMember.addRole/addRoles

* Add GuildMember.removeRole/removeRoles

src/client/rest/RESTMethods.js

@@ -307,10 +307,7 @@ class RESTMethods {
   updateGuildMember(member, data) {
     return new Promise((resolve, reject) => {
       if (data.channel) data.channel_id = this.rest.client.resolver.resolveChannel(data.channel).id;
-      if (data.roles) {
+      if (data.roles) data.roles = data.roles.map(role => role instanceof Role ? role.id : role);
-        if (data.roles instanceof Collection) data.roles = data.roles.array();
-        data.roles = data.roles.map(role => role instanceof Role ? role.id : role);
-      }
 
       let endpoint = Constants.Endpoints.guildMember(member.guild.id, member.id);
       // fix your endpoints, discord ;-;

src/structures/GuildMember.js

@@ -1,4 +1,5 @@
 const TextBasedChannel = require('./interface/TextBasedChannel');
+const Role = require('./Role');
 const Collection = require('../util/Collection');
 
 /**
@@ -164,13 +165,68 @@ class GuildMember {
 
   /**
    * Sets the Roles applied to the member.
-   * @param {Collection<string, Role>|Role[]} roles The roles to apply
+   * @param {Collection<string, Role>|Role[]|string[]} roles The roles or role IDs to apply
    * @returns {Promise<GuildMember>}
    */
   setRoles(roles) {
     return this.edit({ roles });
   }
 
+  /**
+   * Adds a single Role to the member.
+   * @param {Role|string} role The role or ID of the role to add
+   * @returns {Promise<GuildMember>}
+   */
+  addRole(role) {
+    return this.addRoles([role]);
+  }
+
+  /**
+   * Adds multiple roles to the member.
+   * @param {Collection<string, Role>|Role[]|string[]} roles The roles or role IDs to add
+   * @returns {Promise<GuildMember>}
+   */
+  addRoles(roles) {
+    let allRoles;
+    if (roles instanceof Collection) {
+      allRoles = this._roles.slice();
+      for (const role of roles.values()) allRoles.push(role.id);
+    } else {
+      allRoles = this._roles.concat(roles);
+    }
+    return this.edit({ roles: allRoles });
+  }
+
+  /**
+   * Removes a single Role from the member.
+   * @param {Role|string} role The role or ID of the role to remove
+   * @returns {Promise<GuildMember>}
+   */
+  removeRole(role) {
+    return this.removeRoles([role]);
+  }
+
+  /**
+   * Removes multiple roles from the member.
+   * @param {Collection<string, Role>|Role[]|string[]} roles The roles or role IDs to remove
+   * @returns {Promise<GuildMember>}
+   */
+  removeRoles(roles) {
+    const allRoles = this._roles.slice();
+    if (roles instanceof Collection) {
+      for (const role of roles.values()) {
+        const index = allRoles.indexOf(role.id);
+        if (index >= 0) allRoles.splice(index, 1);
+      }
+    } else {
+      for (const role of roles) {
+        const index = allRoles.indexOf(role instanceof Role ? role.id : role);
+        if (index >= 0) allRoles.splice(index, 1);
+      }
+    }
+    return this.edit({ roles: allRoles });
+  }
+
   /**
    * Set the nickname for the Guild Member
    * @param {string} nick The nickname for the Guild Member