Add ability to change url in TS client (dotnet#11102)

src/SignalR/clients/ts/FunctionalTests/ts/HubConnectionTests.ts

@@ -750,6 +750,36 @@ describe("hubConnection", () => {
                 }
             });
         });
+
+        it("can change url in reconnecting state", async (done) => {
+            try {
+                const reconnectingPromise = new PromiseSource();
+                const hubConnection = getConnectionBuilder(transportType)
+                    .withAutomaticReconnect()
+                    .build();
+
+                hubConnection.onreconnecting(() => {
+                    hubConnection.baseUrl = "http://example123.com";
+                    reconnectingPromise.resolve();
+                });
+
+                await hubConnection.start();
+
+                // Induce reconnect
+                (hubConnection as any).serverTimeout();
+
+                await reconnectingPromise;
+
+                expect(hubConnection.baseUrl).toBe("http://example123.com");
+
+                await hubConnection.stop();
+
+                done();
+            } catch (err) {
+                fail(err);
+                done();
+            }
+        });
     });
 
     it("can reconnect after negotiate redirect", async (done) => {

src/SignalR/clients/ts/signalr/src/HttpConnection.ts

@@ -53,7 +53,6 @@ export class HttpConnection implements IConnection {
     // connectionStarted is tracked independently from connectionState, so we can check if the
     // connection ever did successfully transition from connecting to connected before disconnecting.
     private connectionStarted: boolean;
-    private readonly baseUrl: string;
     private readonly httpClient: HttpClient;
     private readonly logger: ILogger;
     private readonly options: IHttpConnectionOptions;
@@ -66,6 +65,7 @@ export class HttpConnection implements IConnection {
     private sendQueue?: TransportSendQueue;
 
     public readonly features: any = {};
+    public baseUrl: string;
     public connectionId?: string;
     public onreceive: ((data: string | ArrayBuffer) => void) | null;
     public onclose: ((e?: Error) => void) | null;

src/SignalR/clients/ts/signalr/src/HubConnection.ts

@@ -127,6 +127,28 @@ export class HubConnection {
         return this.connection ? (this.connection.connectionId || null) : null;
     }
 
+    /** Indicates the url of the {@link HubConnection} to the server. */
+    get baseUrl(): string {
+        return this.connection.baseUrl || "";
+    }
+
+    /**
+     * Sets a new url for the HubConnection. Note that the url can only be changed when the connection is in either the Disconnected or
+     * Reconnecting states.
+     * @param {string} url The url to connect to.
+     */
+    set baseUrl(url: string) {
+        if (this.connectionState !== HubConnectionState.Disconnected && this.connectionState !== HubConnectionState.Reconnecting) {
+            throw new Error("The HubConnection must be in the Disconnected or Reconnecting state to change the url.");
+        }
+
+        if (!url) {
+            throw new Error("The HubConnection url must be a valid url.");
+        }
+
+        this.connection.baseUrl = url;
+    }
+
     /** Starts the connection.
      *
      * @returns {Promise<void>} A Promise that resolves when the connection has been successfully established, or rejects with an error.

src/SignalR/clients/ts/signalr/src/IConnection.ts

@@ -8,6 +8,8 @@ export interface IConnection {
     readonly features: any;
     readonly connectionId?: string;
 
+    baseUrl: string;
+
     start(transferFormat: TransferFormat): Promise<void>;
     send(data: string | ArrayBuffer): Promise<void>;
     stop(error?: Error): Promise<void>;

src/SignalR/clients/ts/signalr/tests/HubConnection.test.ts

@@ -41,6 +41,58 @@ describe("HubConnection", () => {
             });
         });
 
+        it("can change url", async () => {
+            await VerifyLogger.run(async (logger) => {
+                const connection = new TestConnection();
+                const hubConnection = createHubConnection(connection, logger);
+                try {
+                    await hubConnection.start();
+                    await hubConnection.stop();
+                    hubConnection.baseUrl = "http://newurl.com";
+                    expect(hubConnection.baseUrl).toBe("http://newurl.com");
+                } finally {
+                    await hubConnection.stop();
+                }
+            });
+        });
+
+        it("can change url in onclose", async () => {
+            await VerifyLogger.run(async (logger) => {
+                const connection = new TestConnection();
+                const hubConnection = createHubConnection(connection, logger);
+                try {
+                    await hubConnection.start();
+
+                    expect(hubConnection.baseUrl).toBe("http://example.com");
+                    hubConnection.onclose(() => {
+                        hubConnection.baseUrl = "http://newurl.com";
+                    });
+
+                    await hubConnection.stop();
+                    expect(hubConnection.baseUrl).toBe("http://newurl.com");
+                } finally {
+                    await hubConnection.stop();
+                }
+            });
+        });
+
+        it("changing url while active throws", async () => {
+            await VerifyLogger.run(async (logger) => {
+                const connection = new TestConnection();
+                const hubConnection = createHubConnection(connection, logger);
+                try {
+                    await hubConnection.start();
+
+                    expect(() => {
+                        hubConnection.baseUrl = "http://newurl.com";
+                    }).toThrow("The HubConnection must be in the Disconnected or Reconnecting state to change the url.");
+
+                } finally {
+                    await hubConnection.stop();
+                }
+            });
+        });
+
         it("state connected", async () => {
             await VerifyLogger.run(async (logger) => {
                 const connection = new TestConnection();
@@ -1076,7 +1128,7 @@ describe("HubConnection", () => {
                     hubConnection.stream("testMethod").subscribe(NullSubscriber.instance);
 
                     // Send completion to trigger observer.complete()
-                    // Expectation is connection.receive will not to throw
+                    // Expectation is connection.receive will not throw
                     connection.receive({ type: MessageType.Completion, invocationId: connection.lastInvocationId });
                 } finally {
                     await hubConnection.stop();

src/SignalR/clients/ts/signalr/tests/TestConnection.ts

@@ -5,6 +5,7 @@ import { IConnection } from "../src/IConnection";
 import { TextMessageFormat } from "../src/TextMessageFormat";
 
 export class TestConnection implements IConnection {
+    public baseUrl: string;
     public readonly features: any = {};
     public connectionId?: string;
 
@@ -22,6 +23,7 @@ export class TestConnection implements IConnection {
         this.sentData = [];
         this.lastInvocationId = null;
         this.autoHandshake = autoHandshake;
+        this.baseUrl = "http://example.com";
     }
 
     public start(): Promise<void> {