1 files changed, 68 insertions, 0 deletions
diff --git a/devtools/client/webconsole/test/browser/browser_webconsole_lenient_this_warning.js b/devtools/client/webconsole/test/browser/browser_webconsole_lenient_this_warning.js
new file mode 100644
index 0000000000..1d8914b845
--- /dev/null
+++ b/devtools/client/webconsole/test/browser/browser_webconsole_lenient_this_warning.js
@@ -0,0 +1,68 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Check that calling the LenientThis warning is only called when expected.
+const TEST_URI = `data:text/html;charset=utf8,<!DOCTYPE html>${encodeURI(`
+    <h1>LenientThis warning</h1>
+    <script>
+      const el = document.createElement('div');
+      globalThis.htmlDivElementProto = Object.getPrototypeOf(el);
+      function triggerLenientThisWarning(){
+        Object.getOwnPropertyDescriptor(
+          Object.getPrototypeOf(globalThis.htmlDivElementProto),
+          'onmouseenter'
+        ).get.call()
+      }
+    </script>`)}`;
+
+add_task(async function () {
+  const hud = await openNewTabAndConsole(TEST_URI);
+
+  const expectedWarningMessageText =
+    "Ignoring get or set of property that has [LenientThis] ";
+
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {
+    const global = content.wrappedJSObject;
+    global.console.log(global.htmlDivElementProto);
+  });
+
+  info("Wait for a bit so any warning message could be displayed");
+  await wait(1000);
+  await waitFor(() => findConsoleAPIMessage(hud, "HTMLDivElementPrototype"));
+
+  ok(
+    !findWarningMessage(hud, expectedWarningMessageText, ".warn"),
+    "Displaying the HTMLDivElementPrototype does not trigger the LenientThis warning"
+  );
+
+  info(
+    "Call a LenientThis getter with the wrong `this` to trigger a warning message"
+  );
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {
+    content.wrappedJSObject.triggerLenientThisWarning();
+  });
+
+  await waitFor(() =>
+    findWarningMessage(hud, expectedWarningMessageText, ".warn")
+  );
+  ok(
+    true,
+    "Calling the LenientThis getter with an unexpected `this` did triggered the warning"
+  );
+
+  info(
+    "Clear the console and call the LenientThis getter with an unexpected `this` again"
+  );
+  await clearOutput(hud);
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], function () {
+    content.wrappedJSObject.triggerLenientThisWarning();
+  });
+  info("Wait for a bit so any warning message could be displayed");
+  await wait(1000);
+  ok(
+    !findWarningMessage(hud, expectedWarningMessageText, ".warn"),
+    "Calling the LenientThis getter a second time did not trigger the warning again"
+  );
+});