client.js: Fix error handling in downloadKeys

Fix a bug in the error handling in downloadKeys: If the http request failed,
then the exception would get silently swallowed and the promise would never
resolve.

Also: tests!

lib/client.js

@@ -378,10 +378,12 @@ MatrixClient.prototype.uploadKeys = function(maxKeys, deferred) {
  * store.
  * @param {Array} userIds The users to fetch.
  * @param {bool} forceDownload Always download the keys even if cached.
- * @return {object} A promise that will resolve when the keys are downloadded.
+ *
+ * @return {object} A promise that will resolve when the keys are downloaded;
+ * resolves to a map userId->deviceId->device info
  */
 MatrixClient.prototype.downloadKeys = function(userIds, forceDownload) {
-    if (!CRYPTO_ENABLED || this.sessionStore === null) {
+    if (this.sessionStore === null) {
         return q.reject(new Error("End-to-end encryption disabled"));
     }
     var stored = {};
@@ -399,30 +401,29 @@ MatrixClient.prototype.downloadKeys = function(userIds, forceDownload) {
         downloadKeys = true;
         notStored[userId] = {};
     }
-    var deferred = q.defer();
-    if (downloadKeys) {
-        var path = "/keys/query";
-        var content = {device_keys: notStored};
-        var self = this;
-        this._http.authedRequestWithPrefix(
-            undefined, "POST", path, undefined, content,
-            httpApi.PREFIX_UNSTABLE
-        ).then(function(res) {
-            for (var userId in res.device_keys) {
-                if (userId in notStored) {
-                    self.sessionStore.storeEndToEndDevicesForUser(
-                        userId, res.device_keys[userId]
-                    );
-                    // TODO: validate the ed25519 signature.
-                    stored[userId] = res.device_keys[userId];
-                }
-            }
-            deferred.resolve(stored);
-        });
-    } else {
-        deferred.resolve(stored);
+
+    if (!downloadKeys) {
+        return q(stored);
     }
-    return deferred.promise;
+
+    var path = "/keys/query";
+    var content = {device_keys: notStored};
+    var self = this;
+    return this._http.authedRequestWithPrefix(
+        undefined, "POST", path, undefined, content,
+        httpApi.PREFIX_UNSTABLE
+    ).then(function(res) {
+        for (var userId in res.device_keys) {
+            if (userId in notStored) {
+                self.sessionStore.storeEndToEndDevicesForUser(
+                    userId, res.device_keys[userId]
+                );
+                // TODO: validate the ed25519 signature.
+                stored[userId] = res.device_keys[userId];
+            }
+        }
+        return stored;
+    });
 };
 
 /**

spec/integ/matrix-client-methods.spec.js

@@ -6,10 +6,11 @@ var Room = publicGlobals.Room;
 var MatrixInMemoryStore = publicGlobals.MatrixInMemoryStore;
 var Filter = publicGlobals.Filter;
 var utils = require("../test-utils");
+var MockStorageApi = require("../MockStorageApi");
 
 describe("MatrixClient", function() {
     var baseUrl = "http://localhost.or.something";
-    var client, httpBackend, store;
+    var client, httpBackend, store, sessionStore;
     var userId = "@alice:localhost";
     var accessToken = "aseukfgwef";
 
@@ -17,12 +18,17 @@ describe("MatrixClient", function() {
         utils.beforeEach(this);
         httpBackend = new HttpBackend();
         store = new MatrixInMemoryStore();
+
+        var mockStorage = new MockStorageApi();
+        sessionStore = new sdk.WebStorageSessionStore(mockStorage);
+
         sdk.request(httpBackend.requestFn);
         client = sdk.createClient({
             baseUrl: baseUrl,
             userId: userId,
             accessToken: accessToken,
-            store: store
+            store: store,
+            sessionStore: sessionStore,
         });
     });
 
@@ -173,4 +179,45 @@ describe("MatrixClient", function() {
             });
         });
     });
+
+
+    describe("downloadKeys", function() {
+        it("should do an HTTP request and then store the keys", function(done) {
+            var borisKeys = {dev1: {a: 1}};
+            var chazKeys = {dev2: {a: 2}};
+
+            httpBackend.when("POST", "/keys/query").check(function(req) {
+                expect(req.data).toEqual({device_keys: {boris: {}, chaz: {}}});
+            }).respond(200, {
+                device_keys: {
+                    boris: borisKeys,
+                    chaz: chazKeys,
+                },
+            });
+
+            client.downloadKeys(["boris", "chaz"]).then(function(res) {
+                expect(res).toEqual({
+                    boris: borisKeys,
+                    chaz: chazKeys
+                });
+            }).catch(utils.failTest).done(done);
+
+            httpBackend.flush();
+        });
+
+        it("should return a rejected promise if the request fails", function(done) {
+            httpBackend.when("POST", "/keys/query").respond(400);
+
+            var exceptionThrown;
+            client.downloadKeys(["bottom"]).then(function() {
+                fail("download didn't fail");
+            }, function(err) {
+                exceptionThrown = err;
+            }).then(function() {
+                expect(exceptionThrown).toBeTruthy();
+            }).catch(utils.failTest).done(done);
+
+            httpBackend.flush();
+        });
+    });
 });