1 files changed, 28 insertions, 0 deletions
diff --git a/devtools/client/performance-new/test/browser/browser_aboutprofiling-entries.js b/devtools/client/performance-new/test/browser/browser_aboutprofiling-entries.js
new file mode 100644
index 0000000000..4415387b16
--- /dev/null
+++ b/devtools/client/performance-new/test/browser/browser_aboutprofiling-entries.js
@@ -0,0 +1,28 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+add_task(async function test() {
+  info("Test that about:profiling can modify the sampling interval.");
+
+  await withAboutProfiling(async document => {
+    is(
+      getActiveConfiguration().capacity,
+      128 * 1024 * 1024,
+      "The active configuration is set to a specific number initially. If this" +
+        " test fails here, then the magic numbers here may need to be adjusted."
+    );
+
+    info("Change the buffer input to an arbitrarily smaller value.");
+    const bufferInput = await getNearestInputFromText(document, "Buffer size:");
+    setReactFriendlyInputValue(bufferInput, Number(bufferInput.value) * 0.1);
+
+    is(
+      getActiveConfiguration().capacity,
+      256 * 1024,
+      "The capacity changed to a smaller value."
+    );
+  });
+});