added comments to eventlistener test

Author: cosmic-pixel-painter

unittests/files/eventlistener.ts

@@ -9,7 +9,9 @@ document.addEventListener("arbitrary_invalid_event", {
 });
 const divElement: HTMLElement = document.createElement("div");
 
-
+/**
+ * addEventListener works with a single event arg, Event
+ */
 divElement.addEventListener(
   "click",
   (event: Event) => {
@@ -20,20 +22,41 @@ divElement.addEventListener(
   false,
 );
 
-divElement.addEventListener("click", (event: Event) => {
+/**
+ * HTMLElement addEventListener works with a single event arg, UIEvent
+ */
+divElement.addEventListener("click", (event: UIEvent) => {
+  if (event) {
+    return;
+  }
+});
+
+/**
+ * HTMLElement addEventListener works with a custom string and single event arg, Event
+ */
+divElement.addEventListener("beep", (event: Event) => {
   if (event) {
     return;
   }
 });
 
+/**
+ * HTMLElement addEventListener works with a custom string and single event arg, UIEvent
+ */
 divElement.addEventListener("beep", (event: UIEvent) => {
   if (event) {
     return;
   }
 });
 
-const svgElement = document.createElementNS("http://www.w3.org/2000/svg", "svg");
+const svgElement = document.createElementNS(
+  "http://www.w3.org/2000/svg",
+  "svg",
+);
 
+/**
+ * SVGElement addEventListener works with a single event arg, Event
+ */
 svgElement.addEventListener(
   "click",
   (event: Event) => {
@@ -44,12 +67,27 @@ svgElement.addEventListener(
   false,
 );
 
-svgElement.addEventListener("click", (event: Event) => {
+/**
+ * SVGElement addEventListener works with a single event arg, UIEvent
+ */
+svgElement.addEventListener("click", (event: UIEvent) => {
+  if (event) {
+    return;
+  }
+});
+
+/**
+ * SVGElement addEventListener works with a custom string and single event arg, Event
+ */
+svgElement.addEventListener("beep", (event: Event) => {
   if (event) {
     return;
   }
 });
 
+/**
+ * SVGElement addEventListener works with a custom string and single event arg, UIEvent
+ */
 svgElement.addEventListener("beep", (event: UIEvent) => {
   if (event) {
     return;

unittests/files/onerror.ts

@@ -9,7 +9,6 @@ window.onerror = (message, src, lineno, colno, error) => {
 
 const div: HTMLElement = document.createElement("div");
 
-
 /**
  * HTMLElement.onerror works with a single event arg, UIEvent
  */