1 files changed, 42 insertions, 0 deletions
diff --git a/toolkit/components/glean/tests/pytest/test_yaml_indices.py b/toolkit/components/glean/tests/pytest/test_yaml_indices.py
new file mode 100644
index 0000000000..4edb402e03
--- /dev/null
+++ b/toolkit/components/glean/tests/pytest/test_yaml_indices.py
@@ -0,0 +1,42 @@
+# 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/.
+
+import sys
+from os import path
+
+import mozunit
+
+# Shenanigans to import the metrics index's lists of yamls
+FOG_ROOT_PATH = path.abspath(
+    path.join(path.dirname(__file__), path.pardir, path.pardir)
+)
+sys.path.append(FOG_ROOT_PATH)
+import metrics_index
+
+
+def test_yamls_sorted():
+    """
+    Ensure the yamls indices are sorted lexicographically.
+    """
+    # Ignore lists that are the concatenation of others.
+    to_ignore = ["metrics_yamls", "pings_yamls"]
+
+    # Fetch names of all variables defined in the `metrics_index` module.
+    yaml_lists = [
+        item
+        for item in dir(metrics_index)
+        if isinstance(item, list) and not item.startswith("__")
+    ]
+    for name in yaml_lists:
+        if name in to_ignore:
+            continue
+
+        yamls_to_test = metrics_index.__dict__[name]
+        assert (
+            sorted(yamls_to_test) == yamls_to_test
+        ), f"{name} must be be lexicographically sorted."
+
+
+if __name__ == "__main__":
+    mozunit.main()