Bug 601973 - SyncEngine._testDecrypt() yields wrong result [r=mconnor]

Fix a 'this' scoping error in SyncEngine._testDecrypt(). Rename this method to canDecrypt() since it's clearly public API.

Provide tests for SyncEngine.canDecrypt() as well as Service.wipeClient().

services/sync/modules/engines.js

@@ -759,7 +759,7 @@ SyncEngine.prototype = {
     }
   },
 
-  _testDecrypt: function _testDecrypt() {
+  canDecrypt: function canDecrypt() {
     // Report failure even if there's nothing to decrypt
     let canDecrypt = false;
 
@@ -768,8 +768,9 @@ SyncEngine.prototype = {
     test.limit = 1;
     test.sort = "newest";
     test.full = true;
+    let self = this;
     test.recordHandler = function(record) {
-      record.decrypt(ID.get("WeaveCryptoID"), this.cryptoMetaURL);
+      record.decrypt(ID.get("WeaveCryptoID"), self.cryptoMetaURL);
       canDecrypt = true;
     };
 

services/sync/modules/service.js

@@ -1681,7 +1681,7 @@ WeaveSvc.prototype = {
 
       // Fully wipe each engine if it's able to decrypt data
       for each (let engine in engines)
-        if (engine._testDecrypt())
+        if (engine.canDecrypt())
           engine.wipeClient();
 
       // Save the password/passphrase just in-case they aren't restored by sync

services/sync/tests/unit/test_service_wipeClient.js

@@ -0,0 +1,64 @@
+Cu.import("resource://services-sync/service.js");
+Cu.import("resource://services-sync/engines.js");
+
+
+function CanDecryptEngine() {
+  SyncEngine.call(this, "CanDecrypt");
+}
+CanDecryptEngine.prototype = {
+  __proto__: SyncEngine.prototype,
+
+  // Override these methods with mocks for the test
+  canDecrypt: function canDecrypt() {
+    return true;
+  },
+
+  wasWiped: false,
+  wipeClient: function wipeClient() {
+    this.wasWiped = true;
+  }
+};
+Engines.register(CanDecryptEngine);
+
+
+function CannotDecryptEngine() {
+  SyncEngine.call(this, "CannotDecrypt");
+}
+CannotDecryptEngine.prototype = {
+  __proto__: SyncEngine.prototype,
+
+  // Override these methods with mocks for the test
+  canDecrypt: function canDecrypt() {
+    return false;
+  },
+
+  wasWiped: false,
+  wipeClient: function wipeClient() {
+    this.wasWiped = true;
+  }
+};
+Engines.register(CannotDecryptEngine);
+
+
+function test_withEngineList() {
+  try {
+    _("Ensure initial scenario.");
+    do_check_false(Engines.get("candecrypt").wasWiped);
+    do_check_false(Engines.get("cannotdecrypt").wasWiped);
+
+    _("Wipe local engine data.");
+    Service.wipeClient(["candecrypt", "cannotdecrypt"]);
+
+    _("Ensure only the engine that can decrypt was wiped.");
+    do_check_true(Engines.get("candecrypt").wasWiped);
+    do_check_false(Engines.get("cannotdecrypt").wasWiped);
+  } finally {
+    Engines.get("candecrypt").wasWiped = false;
+    Engines.get("cannotdecrypt").wasWiped = false;
+    Service.startOver();
+  }
+}
+
+function run_test() {
+  test_withEngineList();
+}

services/sync/tests/unit/test_syncengine_sync.js

@@ -1087,6 +1087,68 @@ function test_syncFinish_deleteLotsInBatches() {
   }
 }
 
+function test_canDecrypt_noCryptoMeta() {
+  _("SyncEngine.canDecrypt returns false if the engine fails to decrypt items on the server, e.g. due to a missing crypto key.");
+  Svc.Prefs.set("clusterURL", "http://localhost:8080/");
+  Svc.Prefs.set("username", "foo");
+
+  let collection = new ServerCollection();
+  collection.wbos.flying = new ServerWBO(
+      'flying', encryptPayload({id: 'flying',
+                                denomination: "LNER Class A3 4472"}));
+
+  let server = sync_httpd_setup({
+      "/1.0/foo/storage/steam": collection.handler()
+  });
+  do_test_pending();
+  createAndUploadKeypair();
+
+  let engine = makeSteamEngine();
+  try {
+
+    do_check_false(engine.canDecrypt());
+
+  } finally {
+    server.stop(do_test_finished);
+    Svc.Prefs.resetBranch("");
+    Records.clearCache();
+    syncTesting = new SyncTestingInfrastructure(makeSteamEngine);
+  }
+}
+
+function test_canDecrypt_true() {
+  _("SyncEngine.canDecrypt returns true if the engine can decrypt the items on the server.");
+  Svc.Prefs.set("clusterURL", "http://localhost:8080/");
+  Svc.Prefs.set("username", "foo");
+
+  let crypto_steam = new ServerWBO('steam');
+  let collection = new ServerCollection();
+  collection.wbos.flying = new ServerWBO(
+      'flying', encryptPayload({id: 'flying',
+                                denomination: "LNER Class A3 4472"}));
+
+  let server = sync_httpd_setup({
+      "/1.0/foo/storage/crypto/steam": crypto_steam.handler(),
+      "/1.0/foo/storage/steam": collection.handler()
+  });
+  do_test_pending();
+  createAndUploadKeypair();
+  createAndUploadSymKey("http://localhost:8080/1.0/foo/storage/crypto/steam");
+
+  let engine = makeSteamEngine();
+  try {
+
+    do_check_true(engine.canDecrypt());
+
+  } finally {
+    server.stop(do_test_finished);
+    Svc.Prefs.resetBranch("");
+    Records.clearCache();
+    syncTesting = new SyncTestingInfrastructure(makeSteamEngine);
+  }
+}
+
+
 function run_test() {
   test_syncStartup_emptyOrOutdatedGlobalsResetsSync();
   test_syncStartup_metaGet404();
@@ -1104,4 +1166,6 @@ function run_test() {
   test_syncFinish_noDelete();
   test_syncFinish_deleteByIds();
   test_syncFinish_deleteLotsInBatches();
+  test_canDecrypt_noCryptoMeta();
+  test_canDecrypt_true();
 }