Support specifying the registered device ID for an appservice intent

src/appservice/Intent.ts

@@ -300,22 +300,26 @@ export class Intent {
 
     /**
      * Ensures the user is registered
+     * @param deviceId An optional device ID to register with.
      * @returns {Promise<any>} Resolves when complete
      */
     @timedIntentFunctionCall()
-    public async ensureRegistered() {
+    public async ensureRegistered(deviceId?: string) {
         if (!(await Promise.resolve(this.storage.isUserRegistered(this.userId)))) {
             try {
                 const result = await this.client.doRequest("POST", "/_matrix/client/v3/register", null, {
                     type: "m.login.application_service",
                     username: this.userId.substring(1).split(":")[0],
+                    device_id: deviceId,
                 });
 
                 // HACK: Workaround for unit tests
                 if (result['errcode']) {
                     // noinspection ExceptionCaughtLocallyJS
                     throw { body: result }; // eslint-disable-line no-throw-literal
                 }
+
+                this.client.impersonateUserId(this.userId, result["device_id"]);
             } catch (err) {
                 if (err instanceof MatrixError && err.errcode === "M_USER_IN_USE") {
                     await Promise.resolve(this.storage.addRegisteredUser(this.userId));

test/appservice/IntentTest.ts

@@ -178,6 +178,102 @@ describe('Intent', () => {
             expect(addRegisteredSpy.callCount).toBe(1);
         });
 
+        it('should use the provided device ID', async () => {
+            const http = new HttpBackend();
+            setRequestFn(http.requestFn);
+
+            const userId = "@someone:example.org";
+            const botUserId = "@bot:example.org";
+            const asToken = "s3cret";
+            const hsUrl = "https://localhost";
+            const deviceId = "DEVICE_TEST";
+            const appservice = <Appservice>{ botUserId: botUserId };
+
+            const storage = new MemoryStorageProvider();
+            const isRegisteredSpy = simple.mock(storage, "isUserRegistered").callFn((uid) => {
+                expect(uid).toEqual(userId);
+                return false;
+            });
+            const addRegisteredSpy = simple.mock(storage, "addRegisteredUser").callFn((uid) => {
+                expect(uid).toEqual(userId);
+                return true;
+            });
+
+            const options = <IAppserviceOptions>{
+                homeserverUrl: hsUrl,
+                storage: <IAppserviceStorageProvider>storage,
+                registration: {
+                    as_token: asToken,
+                },
+            };
+
+            http.when("POST", "/_matrix/client/v3/register").respond(200, (path, content) => {
+                expect(content).toMatchObject({ type: "m.login.application_service", username: "someone", device_id: deviceId });
+                return {device_id: deviceId};
+            });
+
+            const intent = new Intent(options, userId, appservice);
+            await Promise.all([intent.ensureRegistered(deviceId), http.flushAllExpected()]); // ensureRegistered(deviceId)
+            expect(isRegisteredSpy.callCount).toBe(1);
+            expect(addRegisteredSpy.callCount).toBe(1);
+
+            // noinspection TypeScriptValidateJSTypes
+            http.when("GET", "/test").respond(200, (path, content, req) => {
+                expect(req.queryParams["user_id"]).toBe(userId);
+                expect(req.queryParams["org.matrix.msc3202.device_id"]).toBe(deviceId);
+            });
+
+            await Promise.all([intent.underlyingClient.doRequest("GET", "/test"), http.flushAllExpected()]);
+        });
+
+        it('should impersonate the returned device ID on register', async () => {
+            const http = new HttpBackend();
+            setRequestFn(http.requestFn);
+
+            const userId = "@someone:example.org";
+            const botUserId = "@bot:example.org";
+            const asToken = "s3cret";
+            const hsUrl = "https://localhost";
+            const deviceId = "DEVICE_TEST";
+            const appservice = <Appservice>{ botUserId: botUserId };
+
+            const storage = new MemoryStorageProvider();
+            const isRegisteredSpy = simple.mock(storage, "isUserRegistered").callFn((uid) => {
+                expect(uid).toEqual(userId);
+                return false;
+            });
+            const addRegisteredSpy = simple.mock(storage, "addRegisteredUser").callFn((uid) => {
+                expect(uid).toEqual(userId);
+                return true;
+            });
+
+            const options = <IAppserviceOptions>{
+                homeserverUrl: hsUrl,
+                storage: <IAppserviceStorageProvider>storage,
+                registration: {
+                    as_token: asToken,
+                },
+            };
+
+            http.when("POST", "/_matrix/client/v3/register").respond(200, (path, content) => {
+                expect(content).toMatchObject({ type: "m.login.application_service", username: "someone" });
+                return {device_id: deviceId};
+            });
+
+            const intent = new Intent(options, userId, appservice);
+            await Promise.all([intent.ensureRegistered(), http.flushAllExpected()]);
+            expect(isRegisteredSpy.callCount).toBe(1);
+            expect(addRegisteredSpy.callCount).toBe(1);
+
+            // noinspection TypeScriptValidateJSTypes
+            http.when("GET", "/test").respond(200, (path, content, req) => {
+                expect(req.queryParams["user_id"]).toBe(userId);
+                expect(req.queryParams["org.matrix.msc3202.device_id"]).toBe(deviceId);
+            });
+
+            await Promise.all([intent.underlyingClient.doRequest("GET", "/test"), http.flushAllExpected()]);
+        });
+
         it('should gracefully handle M_USER_IN_USE', async () => {
             const http = new HttpBackend();
             setRequestFn(http.requestFn);