1 files changed, 78 insertions, 0 deletions
diff --git a/toolkit/components/normandy/lib/ShieldPreferences.sys.mjs b/toolkit/components/normandy/lib/ShieldPreferences.sys.mjs
new file mode 100644
index 0000000000..730febe975
--- /dev/null
+++ b/toolkit/components/normandy/lib/ShieldPreferences.sys.mjs
@@ -0,0 +1,78 @@
+/* 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/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  BranchedAddonStudyAction:
+    "resource://normandy/actions/BranchedAddonStudyAction.sys.mjs",
+  AddonStudies: "resource://normandy/lib/AddonStudies.sys.mjs",
+  CleanupManager: "resource://normandy/lib/CleanupManager.sys.mjs",
+  PreferenceExperiments:
+    "resource://normandy/lib/PreferenceExperiments.sys.mjs",
+});
+
+const NS_PREFBRANCH_PREFCHANGE_TOPIC_ID = "nsPref:changed"; // from modules/libpref/nsIPrefBranch.idl
+const PREF_OPT_OUT_STUDIES_ENABLED = "app.shield.optoutstudies.enabled";
+
+/**
+ * Handles Shield-specific preferences, including their UI.
+ */
+export var ShieldPreferences = {
+  init() {
+    // Watch for changes to the Opt-out pref
+    Services.prefs.addObserver(PREF_OPT_OUT_STUDIES_ENABLED, this);
+
+    lazy.CleanupManager.addCleanupHandler(() => {
+      Services.prefs.removeObserver(PREF_OPT_OUT_STUDIES_ENABLED, this);
+    });
+  },
+
+  observe(subject, topic, data) {
+    switch (topic) {
+      case NS_PREFBRANCH_PREFCHANGE_TOPIC_ID:
+        this.observePrefChange(data);
+        break;
+    }
+  },
+
+  async observePrefChange(prefName) {
+    let prefValue;
+    switch (prefName) {
+      // If the opt-out pref changes to be false, disable all current studies.
+      case PREF_OPT_OUT_STUDIES_ENABLED: {
+        prefValue = Services.prefs.getBoolPref(PREF_OPT_OUT_STUDIES_ENABLED);
+        if (!prefValue) {
+          const action = new lazy.BranchedAddonStudyAction();
+          const studyPromises = (await lazy.AddonStudies.getAll()).map(
+            study => {
+              if (!study.active) {
+                return null;
+              }
+              return action.unenroll(study.recipeId, "general-opt-out");
+            }
+          );
+
+          const experimentPromises = (
+            await lazy.PreferenceExperiments.getAll()
+          ).map(experiment => {
+            if (experiment.expired) {
+              return null;
+            }
+            return lazy.PreferenceExperiments.stop(experiment.slug, {
+              reason: "general-opt-out",
+              caller: "observePrefChange::general-opt-out",
+            });
+          });
+
+          const allPromises = studyPromises
+            .concat(experimentPromises)
+            .map(p => p && p.catch(err => console.error(err)));
+          await Promise.all(allPromises);
+        }
+        break;
+      }
+    }
+  },
+};