1 files changed, 84 insertions, 0 deletions
diff --git a/layout/style/test/chrome/test_chrome_only_media_queries.html b/layout/style/test/chrome/test_chrome_only_media_queries.html
new file mode 100644
index 0000000000..1a2fb098c0
--- /dev/null
+++ b/layout/style/test/chrome/test_chrome_only_media_queries.html
@@ -0,0 +1,84 @@
+<!doctype html>
+<title>Test for parsing of non-content-exposed media-queries.</title>
+<script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+<script src="chrome-only-media-queries.js"></script>
+<style></style>
+<script>
+const SHEET = document.querySelector('style');
+
+SimpleTest.waitForExplicitFinish();
+
+async function testWithPref() {
+  await new Promise(r => {
+    SpecialPowers.pushPrefEnv(
+      {
+        set: [
+          ["layout.css.forced-colors.enabled", false],
+        ],
+      },
+      r
+    );
+  });
+  expectKnown("(forced-colors: none)");
+  expectKnown("(forced-colors: active)");
+  expectKnown("(forced-colors)");
+  SimpleTest.finish();
+}
+
+function expect(q, shouldBeKnown) {
+  is(matchMedia(q).media, q, "Serialization should roundtrip");
+  is(matchMedia(`${q} or (not ${q})`).matches, shouldBeKnown, `Query should${shouldBeKnown ? "" : " not"} be known`);
+}
+
+function expectKnown(q) {
+  expect(q, true);
+}
+
+function expectUnkown(q) {
+  expect(q, false);
+}
+
+// Test a toggle that should always match for `1` or `0`.
+function testToggle(toggle) {
+  expectKnown(`(${toggle})`);
+  expectKnown(`(${toggle}: 1)`);
+  expectKnown(`(${toggle}: 0)`);
+
+  expectUnkown(`(${toggle}: foo)`);
+  expectUnkown(`(${toggle}: true)`);
+  expectUnkown(`(${toggle}: false)`);
+  expectUnkown(`(${toggle}: -1)`);
+  expectUnkown(`(min-${toggle}: 0)`);
+  expectUnkown(`(max-${toggle}: 0)`);
+  expectUnkown(`(max-${toggle})`);
+  expectUnkown(`(min-${toggle})`);
+
+  let matches_1 = matchMedia(`(${toggle}: 1)`).matches;
+  let matches_0 = matchMedia(`(${toggle}: 0)`).matches;
+  isnot(matches_0, matches_1, `Should not match both true and false: ${toggle}`);
+  is(matches_0 || matches_1, true, `Should match at least one: ${toggle}`);
+}
+
+for (let toggle of CHROME_ONLY_TOGGLES) {
+  testToggle(toggle)
+}
+
+for (let query of CHROME_ONLY_QUERIES) {
+  expectKnown(query);
+}
+
+// These might be exposed to content by pref, we just want to make sure they're
+// always exposed to chrome.
+expectKnown("(prefers-contrast: more)")
+expectKnown("(prefers-contrast: no-preference)")
+expectKnown("(prefers-contrast: less)");
+expectKnown("(prefers-contrast)")
+
+expectKnown("(forced-colors: none)");
+expectKnown("(forced-colors: active)");
+expectKnown("(forced-colors)");
+
+expectUnkown("(-moz-platform: )");
+
+testWithPref();
+</script>