1 files changed, 47 insertions, 0 deletions
diff --git a/toolkit/components/extensions/test/xpcshell/test_change_backgroundServiceWorker_enabled_pref_false.js b/toolkit/components/extensions/test/xpcshell/test_change_backgroundServiceWorker_enabled_pref_false.js
new file mode 100644
index 0000000000..0be36788c1
--- /dev/null
+++ b/toolkit/components/extensions/test/xpcshell/test_change_backgroundServiceWorker_enabled_pref_false.js
@@ -0,0 +1,47 @@
+"use strict";
+
+// extensions.backgroundServiceWorker.enabled=false is set in the test manifest
+// because there is no guarantee that the pref value set at runtime takes effect
+// due to the pref being declared "mirror: once". The value of this pref is
+// frozen upon the first access to any "mirror:once" pref, and we can therefore
+// not assume the pref value to be mutable at runtime.
+const PREF_EXT_SW_ENABLED = "extensions.backgroundServiceWorker.enabled";
+
+add_task(async function test_backgroundServiceWorkerEnabled() {
+  // Sanity check:
+  Assert.equal(
+    Services.prefs.getBoolPref(PREF_EXT_SW_ENABLED),
+    false,
+    "Pref value should be false"
+  );
+  Assert.equal(
+    WebExtensionPolicy.backgroundServiceWorkerEnabled,
+    false,
+    "backgroundServiceWorkerEnabled should be false"
+  );
+
+  if (AppConstants.MOZ_WEBEXT_WEBIDL_ENABLED) {
+    Assert.ok(
+      !Services.prefs.prefIsLocked(PREF_EXT_SW_ENABLED),
+      "Pref should be not locked when MOZ_WEBEXT_WEBIDL_ENABLED is true"
+    );
+  } else {
+    Assert.ok(
+      Services.prefs.prefIsLocked(PREF_EXT_SW_ENABLED),
+      "Pref should be locked when MOZ_WEBEXT_WEBIDL_ENABLED is false"
+    );
+    Services.prefs.unlockPref(PREF_EXT_SW_ENABLED);
+  }
+
+  // Flip pref and test result.
+  Services.prefs.setBoolPref(PREF_EXT_SW_ENABLED, true);
+  Assert.ok(
+    Services.prefs.getBoolPref(PREF_EXT_SW_ENABLED),
+    "pref can change after setting it"
+  );
+  Assert.equal(
+    WebExtensionPolicy.backgroundServiceWorkerEnabled,
+    false,
+    "backgroundServiceWorkerEnabled is still false despite the pref flip"
+  );
+});