Sanity-check decaffeinate class Events

assets/javascripts/lib/events.js

@@ -1,29 +1,13 @@
-// TODO: This file was created by bulk-decaffeinate.
-// Sanity-check the conversion and remove this comment.
-/*
- * decaffeinate suggestions:
- * DS101: Remove unnecessary use of Array.from
- * DS102: Remove unnecessary code created because of implicit returns
- * DS104: Avoid inline assignments
- * DS207: Consider shorter variations of null checks
- * DS208: Avoid top-level this
- * Full docs: https://github.com/decaffeinate/decaffeinate/blob/main/docs/suggestions.md
- */
 class Events {
   on(event, callback) {
     if (event.indexOf(" ") >= 0) {
-      for (var name of Array.from(event.split(" "))) {
+      for (var name of event.split(" ")) {
         this.on(name, callback);
       }
     } else {
-      let base;
+      this._callbacks ||= {};
-      ((base =
+      this._callbacks[event] ||= [];
-        this._callbacks != null ? this._callbacks : (this._callbacks = {}))[
+      this._callbacks[event].push(callback);
-        event
-      ] != null
-        ? base[event]
-        : (base[event] = [])
-      ).push(callback);
     }
     return this;
   }
@@ -31,12 +15,11 @@ class Events {
   off(event, callback) {
     let callbacks, index;
     if (event.indexOf(" ") >= 0) {
-      for (var name of Array.from(event.split(" "))) {
+      for (var name of event.split(" ")) {
         this.off(name, callback);
       }
     } else if (
-      (callbacks =
+      (callbacks = this._callbacks?.[event]) &&
-        this._callbacks != null ? this._callbacks[event] : undefined) &&
       (index = callbacks.indexOf(callback)) >= 0
     ) {
       callbacks.splice(index, 1);
@@ -51,7 +34,7 @@ class Events {
     this.eventInProgress = { name: event, args };
     const callbacks = this._callbacks?.[event];
     if (callbacks) {
-      for (let callback of Array.from(callbacks.slice(0))) {
+      for (let callback of callbacks.slice(0)) {
         if (typeof callback === "function") {
           callback(...args);
         }
@@ -59,14 +42,14 @@ class Events {
     }
     this.eventInProgress = null;
     if (event !== "all") {
-      this.trigger("all", event, ...Array.from(args));
+      this.trigger("all", event, ...args);
     }
     return this;
   }
 
   removeEvent(event) {
     if (this._callbacks != null) {
-      for (var name of Array.from(event.split(" "))) {
+      for (var name of event.split(" ")) {
         delete this._callbacks[name];
       }
     }