1 files changed, 49 insertions, 0 deletions
diff --git a/devtools/client/webconsole/test/browser/browser_webconsole_longstring.js b/devtools/client/webconsole/test/browser/browser_webconsole_longstring.js
new file mode 100644
index 0000000000..9009e86641
--- /dev/null
+++ b/devtools/client/webconsole/test/browser/browser_webconsole_longstring.js
@@ -0,0 +1,49 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that very long strings can be expanded and collapsed, and do not hang the browser.
+
+"use strict";
+
+const TEST_URI =
+  "data:text/html,<!DOCTYPE html><meta charset=utf8>Test LongString hang";
+
+const LONGSTRING = `foobar${"a".repeat(
+  9000
+)}foobaz${"abbababazomglolztest".repeat(100)}boom!`;
+
+add_task(async function () {
+  const hud = await openNewTabAndConsole(TEST_URI);
+
+  info("Log a longString");
+  const onMessage = waitForMessageByType(
+    hud,
+    LONGSTRING.slice(0, 50),
+    ".console-api"
+  );
+  SpecialPowers.spawn(gBrowser.selectedBrowser, [LONGSTRING], str => {
+    content.console.log(str);
+  });
+
+  const { node } = await onMessage;
+  const arrow = node.querySelector(".arrow");
+  ok(arrow, "longString expand arrow is shown");
+
+  info("wait for long string expansion");
+  const onLongStringFullTextDisplayed = waitFor(() =>
+    findConsoleAPIMessage(hud, LONGSTRING)
+  );
+  arrow.click();
+  await onLongStringFullTextDisplayed;
+
+  ok(true, "The full text of the longString is displayed");
+
+  info("wait for long string collapse");
+  const onLongStringCollapsed = waitFor(
+    () => !findConsoleAPIMessage(hud, LONGSTRING)
+  );
+  arrow.click();
+  await onLongStringCollapsed;
+
+  ok(true, "The longString can be collapsed");
+});