Handle null and undefined thrown as exceptions

Closes #3183.
jsdom · May 22, 2021 · 39b7972 · 39b7972
1 parent 04f6c13
commit 39b7972
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Showing 3 changed files with 55 additions and 2 deletions.
diff --git a/lib/jsdom/living/helpers/runtime-script-errors.js b/lib/jsdom/living/helpers/runtime-script-errors.js
@@ -18,6 +18,10 @@ function reportAnError(line, col, target, errorObject, message, location) {
 
   target[errorReportingMode] = true;
 
+  if (typeof message !== "string") {
+    message = "uncaught exception: " + util.inspect(errorObject);
+  }
+
   const event = createAnEvent("error", target._globalObject, ErrorEvent, {
     cancelable: true,
     message,
@@ -55,7 +59,7 @@ module.exports = function reportException(window, error, filenameHint) {
 
   const windowImpl = idlUtils.implForWrapper(window);
 
-  const handled = reportAnError(lineNumber, columnNumber, windowImpl, error, error.message, fileName);
+  const handled = reportAnError(lineNumber, columnNumber, windowImpl, error, error && error.message, fileName);
 
   if (!handled) {
     const errorString = shouldBeDisplayedAsError(error) ? `[${error.name}: ${error.message}]` : util.inspect(error);
@@ -68,5 +72,5 @@ module.exports = function reportException(window, error, filenameHint) {
 };
 
 function shouldBeDisplayedAsError(x) {
-  return x.name && x.message !== undefined && x.stack;
+  return x && x.name && x.message !== undefined && x.stack;
 }
diff --git a/test/api/jsdom-errors.js b/test/api/jsdom-errors.js
@@ -33,4 +33,21 @@ describe("API: virtual console jsdomErrors", () => {
 
     assert.isEmpty(errors);
   });
+
+  it("should emit unhandled null value thrown in inline event handlers", t => {
+    const virtualConsole = new VirtualConsole();
+    virtualConsole.on("jsdomError", error => {
+      assert.ok(error instanceof Error);
+      assert.equal(error.message, "Uncaught null");
+      assert.isNull(error.detail);
+      t.done();
+    });
+
+    const html = `<body onclick="throw null"></body>`;
+    const doc = (new JSDOM(html, { virtualConsole, runScripts: "dangerously" })).window.document;
+
+    doc.body.click();
+  }, {
+    async: true
+  });
 });
diff --git a/...pstream/html/webappapis/scripting/processing-model-2/window-onerror-event-throw-null.html b/...pstream/html/webappapis/scripting/processing-model-2/window-onerror-event-throw-null.html
@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<meta charset="UTF-8">
+<title>window.onerror: throwing null in event listeners</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+  "use strict";
+
+  setup({ allow_uncaught_exception: true });
+
+  test(() => {
+    let errorEvents = 0;
+    let errorEvent;
+    window.addEventListener("error", event => {
+      errorEvent = event;
+      ++errorEvents;
+    });
+
+    const element = document.createElement("div");
+
+    element.addEventListener("click", () => {
+      throw null; // eslint-disable-line no-throw-literal
+    });
+
+    element.dispatchEvent(new Event("click"));
+
+    assert_equals(errorEvents, 1);
+    assert_equals(errorEvent.message, "uncaught exception: null");
+    assert_equals(errorEvent.error, null);
+  }, "Throwing null in event listener");
+</script>