1 files changed, 153 insertions, 0 deletions
diff --git a/services/settings/test/unit/test_remote_settings_recover_broken.js b/services/settings/test/unit/test_remote_settings_recover_broken.js
new file mode 100644
index 0000000000..cedd5cbe30
--- /dev/null
+++ b/services/settings/test/unit/test_remote_settings_recover_broken.js
@@ -0,0 +1,153 @@
+/* import-globals-from ../../../common/tests/unit/head_helpers.js */
+
+const { SyncHistory } = ChromeUtils.importESModule(
+  "resource://services-settings/SyncHistory.sys.mjs"
+);
+const { RemoteSettingsClient } = ChromeUtils.importESModule(
+  "resource://services-settings/RemoteSettingsClient.sys.mjs"
+);
+const { RemoteSettings } = ChromeUtils.importESModule(
+  "resource://services-settings/remote-settings.sys.mjs"
+);
+const { Utils } = ChromeUtils.importESModule(
+  "resource://services-settings/Utils.sys.mjs"
+);
+
+const PREF_SETTINGS_SERVER = "services.settings.server";
+const CHANGES_PATH = "/v1" + Utils.CHANGES_PATH;
+const BROKEN_SYNC_THRESHOLD = 10; // See default pref value
+
+let server;
+let client;
+let maybeSyncBackup;
+
+async function clear_state() {
+  // Disable logging output.
+  Services.prefs.setCharPref("services.settings.loglevel", "critical");
+  // Pull data from the test server.
+  Services.prefs.setCharPref(
+    PREF_SETTINGS_SERVER,
+    `http://localhost:${server.identity.primaryPort}/v1`
+  );
+
+  // Clear sync history.
+  await new SyncHistory("").clear();
+
+  // Simulate a response whose ETag gets incremented on each call
+  // (in order to generate several history entries, indexed by timestamp).
+  let timestamp = 1337;
+  server.registerPathHandler(CHANGES_PATH, (request, response) => {
+    response.setStatusLine(null, 200, "OK");
+    response.setHeader("Content-Type", "application/json; charset=UTF-8");
+    response.setHeader("Date", new Date(1000000).toUTCString());
+    response.setHeader("ETag", `"${timestamp}"`);
+    response.write(
+      JSON.stringify({
+        timestamp,
+        changes: [
+          {
+            last_modified: ++timestamp,
+            bucket: "main",
+            collection: "desktop-manager",
+          },
+        ],
+      })
+    );
+  });
+
+  // Restore original maybeSync() method between each test.
+  client.maybeSync = maybeSyncBackup;
+}
+
+function run_test() {
+  // Set up an HTTP Server
+  server = new HttpServer();
+  server.start(-1);
+
+  client = RemoteSettings("desktop-manager");
+  maybeSyncBackup = client.maybeSync;
+
+  run_next_test();
+
+  registerCleanupFunction(() => {
+    server.stop(() => {});
+    // Restore original maybeSync() method when test suite is done.
+    client.maybeSync = maybeSyncBackup;
+  });
+}
+
+add_task(clear_state);
+
+add_task(async function test_db_is_destroyed_when_sync_is_broken() {
+  // Simulate a successful sync.
+  client.maybeSync = async () => {
+    // Store some data in local DB.
+    await client.db.importChanges({}, 1515, []);
+  };
+  await RemoteSettings.pollChanges({ trigger: "timer" });
+
+  // Register a client with a failing sync method.
+  client.maybeSync = () => {
+    throw new RemoteSettingsClient.InvalidSignatureError(
+      "main/desktop-manager"
+    );
+  };
+
+  // Now obtain several failures in a row.
+  for (var i = 0; i < BROKEN_SYNC_THRESHOLD; i++) {
+    try {
+      await RemoteSettings.pollChanges({ trigger: "timer" });
+    } catch (e) {}
+  }
+
+  // Synchronization is in broken state.
+  Assert.equal(
+    await client.db.getLastModified(),
+    1515,
+    "Local DB was not destroyed yet"
+  );
+
+  // Synchronize again. Broken state will be detected.
+  try {
+    await RemoteSettings.pollChanges({ trigger: "timer" });
+  } catch (e) {}
+
+  // DB was destroyed.
+  Assert.equal(
+    await client.db.getLastModified(),
+    null,
+    "Local DB was destroyed"
+  );
+});
+
+add_task(clear_state);
+
+add_task(async function test_db_is_not_destroyed_when_state_is_server_error() {
+  // Since we don't mock the server endpoints to obtain the changeset of this
+  // collection, the call to `maybeSync()` will fail with network errors.
+
+  // Store some data in local DB.
+  await client.db.importChanges({}, 1515, []);
+
+  // Now obtain several failures in a row.
+  let lastError;
+  for (var i = 0; i < BROKEN_SYNC_THRESHOLD + 1; i++) {
+    try {
+      await RemoteSettings.pollChanges({ trigger: "timer" });
+    } catch (e) {
+      lastError = e;
+    }
+  }
+  Assert.ok(
+    /Cannot parse server content/.test(lastError.message),
+    "Error is about server"
+  );
+  // DB was not destroyed.
+  Assert.equal(
+    await client.db.getLastModified(),
+    1515,
+    "Local DB was not destroyed"
+  );
+});
+
+add_task(clear_state);