added onerror test

Author: cosmic-pixel-painter

unittests/files/onerror.ts

@@ -0,0 +1,59 @@
+/**
+ * window.onerror works as intended with global event handler
+ */
+window.onerror = (message, src, lineno, colno, error) => {
+  if (message && src && lineno && colno && error) {
+    return;
+  }
+};
+
+const div: HTMLElement = document.createElement("div");
+
+
+/**
+ * HTMLElement.onerror works with a single event arg, UIEvent
+ */
+div.onerror = (event: UIEvent) => {
+  if (event) {
+    return;
+  }
+};
+
+/**
+ * HTMLElement.onerror works with a single event arg, Event
+ */
+div.onerror = (event: Event) => {
+  if (event) {
+    return;
+  }
+};
+
+/**
+ * HTMLElement onerror is nullable
+ */
+div.onerror = null;
+
+const svg = document.createElementNS("http://www.w3.org/2000/svg", "svg");
+
+/**
+ * SVGElement.onerror works with a single event arg, UIEvent
+ */
+svg.onerror = (event: UIEvent) => {
+  if (event) {
+    return;
+  }
+};
+
+/**
+ * SVGElement.onerror works with a single event arg, Event
+ */
+svg.onerror = (event: Event) => {
+  if (event) {
+    return;
+  }
+};
+
+/**
+ * SVGElement onerror is nullable
+ */
+svg.onerror = null;