1 files changed, 9 insertions, 0 deletions
diff --git a/testing/web-platform/tests/mathml/support/fonts.js b/testing/web-platform/tests/mathml/support/fonts.js
new file mode 100644
index 0000000000..f05d7278ad
--- /dev/null
+++ b/testing/web-platform/tests/mathml/support/fonts.js
@@ -0,0 +1,9 @@
+function loadAllFonts() {
+  // Use this to wait for all fonts in a testcase to load rather than just using
+  // `document.fonts.ready.then(...)` in the load event, since there are compat
+  // issues between browsers as to whether content initiated font loads are
+  // guaranteed to have been started by this point.
+
+  // FIXME: Use Promise.all() to cause an obvious failure when a font fails to load.
+  return Promise.allSettled([...document.fonts].map(f => f.load()));
+}