feat(ThreadChannel): add ThreadChannel#viewable (#6975)

src/structures/Message.js

@@ -551,7 +551,15 @@ class Message extends Base {
    * @readonly
    */
   get editable() {
-    return Boolean(this.author.id === this.client.user.id && !this.deleted && (!this.guild || this.channel?.viewable));
+    const precheck = Boolean(
+      this.author.id === this.client.user.id && !this.deleted && (!this.guild || this.channel?.viewable),
+    );
+    // Regardless of permissions thread messages cannot be edited if
+    // the thread is locked.
+    if (this.channel?.isThread()) {
+      return precheck && !this.channel.locked;
+    }
+    return precheck;
   }
 
   /**

src/structures/ThreadChannel.js

@@ -442,6 +442,18 @@ class ThreadChannel extends Channel {
     return this.permissionsFor(this.client.user)?.has(Permissions.FLAGS.MANAGE_THREADS, false);
   }
 
+  /**
+   * Whether the thread is viewable by the client user
+   * @type {boolean}
+   * @readonly
+   */
+  get viewable() {
+    if (this.client.user.id === this.guild.ownerId) return true;
+    const permissions = this.permissionsFor(this.client.user);
+    if (!permissions) return false;
+    return permissions.has(Permissions.FLAGS.VIEW_CHANNEL, false);
+  }
+
   /**
    * Whether the client user can send messages in this thread
    * @type {boolean}

typings/index.d.ts

@@ -2099,6 +2099,7 @@ export class ThreadChannel extends TextBasedChannel(Channel) {
   public readonly joined: boolean;
   public locked: boolean | null;
   public readonly manageable: boolean;
+  public readonly viewable: boolean;
   public readonly sendable: boolean;
   public memberCount: number | null;
   public messageCount: number | null;