Fix username change logging and saving. Re-enable migrations.

src/plugins/UsernameSaver.ts

@@ -0,0 +1,31 @@
+import { decorators as d, GlobalPlugin } from "knub";
+import { UsernameHistory } from "../data/UsernameHistory";
+import { Member, User } from "eris";
+
+export class UsernameSaver extends GlobalPlugin {
+  public static pluginName = "username_saver";
+
+  protected usernameHistory: UsernameHistory;
+
+  async onLoad() {
+    this.usernameHistory = UsernameHistory.getInstance(null);
+  }
+
+  protected async updateUsername(user: User) {
+    const newUsername = `${user.username}#${user.discriminator}`;
+    const latestEntry = await this.usernameHistory.getLastEntry(user.id);
+    if (newUsername !== latestEntry.username) {
+      await this.usernameHistory.addEntry(user.id, newUsername);
+    }
+  }
+
+  @d.event("userUpdate", null, false)
+  async onUserUpdate(user: User) {
+    this.updateUsername(user);
+  }
+
+  @d.event("guildMemberAdd", null, false)
+  async onGuildMemberAdd(_, member: Member) {
+    this.updateUsername(member.user);
+  }
+}