GuildChannel.permissionsFor(role) (#2254)

* GuildChannel.permissionsFor(role)

* 1Comp's requested changes

src/structures/GuildChannel.js

@@ -92,31 +92,16 @@ class GuildChannel extends Channel {
   }
 
   /**
-   * Gets the overall set of permissions for a user in this channel, taking into account roles and permission
-   * overwrites.
-   * @param {GuildMemberResolvable} member The user that you want to obtain the overall permissions for
+   * Gets the overall set of permissions for a member or role in this channel, taking into account channel overwrites.
+   * @param {GuildMemberResolvable|RoleResolvable} memberOrRole The member or role to obtain the overall permissions for
    * @returns {?Permissions}
    */
-  permissionsFor(member) {
-    member = this.guild.members.resolve(member);
-    if (!member) return null;
-    if (member.id === this.guild.ownerID) return new Permissions(Permissions.ALL).freeze();
-
-    const roles = member.roles;
-    const permissions = new Permissions(roles.map(role => role.permissions));
-
-    if (permissions.has(Permissions.FLAGS.ADMINISTRATOR)) return new Permissions(Permissions.ALL).freeze();
-
-    const overwrites = this.overwritesFor(member, true, roles);
-
-    return permissions
-      .remove(overwrites.everyone ? overwrites.everyone.denied : 0)
-      .add(overwrites.everyone ? overwrites.everyone.allowed : 0)
-      .remove(overwrites.roles.length > 0 ? overwrites.roles.map(role => role.denied) : 0)
-      .add(overwrites.roles.length > 0 ? overwrites.roles.map(role => role.allowed) : 0)
-      .remove(overwrites.member ? overwrites.member.denied : 0)
-      .add(overwrites.member ? overwrites.member.allowed : 0)
-      .freeze();
+  permissionsFor(memberOrRole) {
+    const member = this.guild.members.resolve(memberOrRole);
+    if (member) return this.memberPermissions(member);
+    const role = this.guild.roles.resolve(memberOrRole);
+    if (role) return this.rolePermissions(role);
+    return null;
   }
 
   overwritesFor(member, verified = false, roles = null) {
@@ -145,6 +130,52 @@ class GuildChannel extends Channel {
     };
   }
 
+  /**
+   * Gets the overall set of permissions for a member in this channel, taking into account channel overwrites.
+   * @param {GuildMember} member The member to obtain the overall permissions for
+   * @returns {Permissions}
+   * @private
+   */
+  memberPermissions(member) {
+    if (member.id === this.guild.ownerID) return new Permissions(Permissions.ALL).freeze();
+
+    const roles = member.roles;
+    const permissions = new Permissions(roles.map(role => role.permissions));
+
+    if (permissions.has(Permissions.FLAGS.ADMINISTRATOR)) return new Permissions(Permissions.ALL).freeze();
+
+    const overwrites = this.overwritesFor(member, true, roles);
+
+    return permissions
+      .remove(overwrites.everyone ? overwrites.everyone.denied : 0)
+      .add(overwrites.everyone ? overwrites.everyone.allowed : 0)
+      .remove(overwrites.roles.length > 0 ? overwrites.roles.map(role => role.denied) : 0)
+      .add(overwrites.roles.length > 0 ? overwrites.roles.map(role => role.allowed) : 0)
+      .remove(overwrites.member ? overwrites.member.denied : 0)
+      .add(overwrites.member ? overwrites.member.allowed : 0)
+      .freeze();
+  }
+
+  /**
+   * Gets the overall set of permissions for a role in this channel, taking into account channel overwrites.
+   * @param {Role} role The role to obtain the overall permissions for
+   * @returns {Permissions}
+   * @private
+   */
+  rolePermissions(role) {
+    if (role.permissions.has(Permissions.FLAGS.ADMINISTRATOR)) return new Permissions(Permissions.ALL).freeze();
+
+    const everyoneOverwrites = this.permissionOverwrites.get(this.guild.id);
+    const roleOverwrites = this.permissionOverwrites.get(role.id);
+
+    return role.permissions
+      .remove(everyoneOverwrites ? everyoneOverwrites.denied : 0)
+      .add(everyoneOverwrites ? everyoneOverwrites.allowed : 0)
+      .remove(roleOverwrites ? roleOverwrites.denied : 0)
+      .add(roleOverwrites ? roleOverwrites.allowed : 0)
+      .freeze();
+  }
+
   /**
    * An object mapping permission flags to `true` (enabled), `null` (default) or `false` (disabled).
    * ```js

src/structures/GuildMember.js

@@ -295,9 +295,9 @@ class GuildMember extends Base {
    * @returns {?Permissions}
    */
   permissionsIn(channel) {
-    channel = this.client.channels.resolve(channel);
-    if (!channel || !channel.guild) throw new Error('GUILD_CHANNEL_RESOLVE');
-    return channel.permissionsFor(this);
+    channel = this.guild.channels.resolve(channel);
+    if (!channel) throw new Error('GUILD_CHANNEL_RESOLVE');
+    return channel.memberPermissions(this);
   }
 
   /**

src/structures/Role.js

@@ -195,6 +195,18 @@ class Role extends Base {
       });
   }
 
+  /**
+   * Returns `channel.permissionsFor(role)`. Returns permissions for a role in a guild channel,
+   * taking into account permission overwrites.
+   * @param {ChannelResolvable} channel The guild channel to use as context
+   * @returns {?Permissions}
+   */
+  permissionsIn(channel) {
+    channel = this.guild.channels.resolve(channel);
+    if (!channel) throw new Error('GUILD_CHANNEL_RESOLVE');
+    return channel.rolePermissions(this);
+  }
+
   /**
    * Sets a new name for the role.
    * @param {string} name The new name of the role