Replace exporting impl classes by adding factory functions

Author: microbit-grace

lib/bluetooth.ts

@@ -138,10 +138,17 @@ export interface MicrobitWebBluetoothConnection extends DeviceConnection {
   writeUART(data: Uint8Array): Promise<void>;
 }
 
+/**
+ * A Bluetooth connection factory.
+ */
+export const createWebBluetoothConnection = (
+  options?: MicrobitWebBluetoothConnectionOptions,
+) => new MicrobitWebBluetoothConnectionImpl(options);
+
 /**
  * A Bluetooth connection to a micro:bit device.
  */
-export class MicrobitWebBluetoothConnectionImpl
+class MicrobitWebBluetoothConnectionImpl
   extends TypedEventTarget<DeviceConnectionEventMap & ServiceConnectionEventMap>
   implements MicrobitWebBluetoothConnection
 {

lib/index.ts

@@ -1,7 +1,7 @@
 import { AccelerometerData, AccelerometerDataEvent } from "./accelerometer.js";
 import {
+  createWebBluetoothConnection,
   MicrobitWebBluetoothConnection,
-  MicrobitWebBluetoothConnectionImpl,
   MicrobitWebBluetoothConnectionOptions,
 } from "./bluetooth.js";
 import { BoardId } from "./board-id.js";
@@ -33,13 +33,13 @@ import { MagnetometerData, MagnetometerDataEvent } from "./magnetometer.js";
 import { ServiceConnectionEventMap } from "./service-events.js";
 import { UARTDataEvent } from "./uart.js";
 import {
+  createRadioBridgeConnection,
   MicrobitRadioBridgeConnection,
-  MicrobitRadioBridgeConnectionImpl,
   MicrobitRadioBridgeConnectionOptions,
 } from "./usb-radio-bridge.js";
 import {
+  createWebUSBConnection,
   MicrobitWebUSBConnection,
-  MicrobitWebUSBConnectionImpl,
   MicrobitWebUSBConnectionOptions,
 } from "./usb.js";
 
@@ -50,14 +50,14 @@ export {
   BoardId,
   ConnectionStatus,
   ConnectionStatusEvent,
+  createRadioBridgeConnection,
   createUniversalHexFlashDataSource,
+  createWebBluetoothConnection,
+  createWebUSBConnection,
   DeviceConnectionEventMap,
   DeviceError,
   FlashDataError,
   FlashEvent,
-  MicrobitRadioBridgeConnectionImpl,
-  MicrobitWebBluetoothConnectionImpl,
-  MicrobitWebUSBConnectionImpl,
   SerialDataEvent,
   SerialErrorEvent,
   SerialResetEvent,

lib/usb-radio-bridge.ts

@@ -22,7 +22,7 @@ import {
   TypedServiceEventDispatcher,
 } from "./service-events.js";
 import * as protocol from "./usb-serial-protocol.js";
-import { MicrobitWebUSBConnectionImpl } from "./usb.js";
+import { MicrobitWebUSBConnection } from "./usb.js";
 
 const connectTimeoutDuration: number = 10000;
 
@@ -50,12 +50,20 @@ export interface MicrobitRadioBridgeConnection extends DeviceConnection {
   setRemoteDeviceId(deviceId: number): void;
 }
 
+/**
+ * A radio bridge connection factory.
+ */
+export const createRadioBridgeConnection = (
+  delegate: MicrobitWebUSBConnection,
+  options?: MicrobitRadioBridgeConnectionOptions,
+) => new MicrobitRadioBridgeConnectionImpl(delegate, options);
+
 /**
  * Wraps around a USB connection to implement a subset of services over a serial protocol.
  *
  * When it connects/disconnects it affects the delegate connection.
  */
-export class MicrobitRadioBridgeConnectionImpl
+class MicrobitRadioBridgeConnectionImpl
   extends TypedEventTarget<DeviceConnectionEventMap & ServiceConnectionEventMap>
   implements MicrobitRadioBridgeConnection
 {
@@ -87,7 +95,7 @@ export class MicrobitRadioBridgeConnectionImpl
   };
 
   constructor(
-    private delegate: MicrobitWebUSBConnectionImpl,
+    private delegate: MicrobitWebUSBConnection,
     options?: MicrobitRadioBridgeConnectionOptions,
   ) {
     super();
@@ -302,7 +310,7 @@ class RadioBridgeSerialSession {
   constructor(
     private logging: Logging,
     private remoteDeviceId: number,
-    private delegate: MicrobitWebUSBConnectionImpl,
+    private delegate: MicrobitWebUSBConnection,
     private dispatchTypedEvent: TypedServiceEventDispatcher,
     private callbacks: ConnectCallbacks,
   ) {}

lib/usb.test.ts

@@ -10,7 +10,7 @@
  * with a tweak to Buffer.
  */
 import { ConnectionStatus, ConnectionStatusEvent } from "./device.js";
-import { MicrobitWebUSBConnectionImpl } from "./usb.js";
+import { createWebUSBConnection } from "./usb.js";
 import { beforeAll, expect, vi, describe, it } from "vitest";
 
 vi.mock("./webusb-device-wrapper", () => ({
@@ -27,7 +27,7 @@ const describeDeviceOnly = process.env.TEST_MODE_DEVICE
 describe("MicrobitWebUSBConnection (WebUSB unsupported)", () => {
   it("notices if WebUSB isn't supported", () => {
     (global as any).navigator = {};
-    const microbit = new MicrobitWebUSBConnectionImpl();
+    const microbit = createWebUSBConnection();
     expect(microbit.status).toBe(ConnectionStatus.NOT_SUPPORTED);
   });
 });
@@ -49,13 +49,13 @@ describeDeviceOnly("MicrobitWebUSBConnection (WebUSB supported)", () => {
   });
 
   it("shows no device as initial status", () => {
-    const microbit = new MicrobitWebUSBConnectionImpl();
+    const microbit = createWebUSBConnection();
     expect(microbit.status).toBe(ConnectionStatus.NO_AUTHORIZED_DEVICE);
   });
 
   it("connects and disconnects updating status and events", async () => {
     const events: ConnectionStatus[] = [];
-    const connection = new MicrobitWebUSBConnectionImpl();
+    const connection = createWebUSBConnection();
     connection.addEventListener("status", (event: ConnectionStatusEvent) => {
       events.push(event.status);
     });

lib/usb.ts

@@ -75,10 +75,17 @@ export interface MicrobitWebUSBConnection extends DeviceConnection {
   softwareReset(): Promise<void>;
 }
 
+/**
+ * A WebUSB connection factory.
+ */
+export const createWebUSBConnection = (
+  options?: MicrobitWebUSBConnectionOptions,
+) => new MicrobitWebUSBConnectionImpl(options);
+
 /**
  * A WebUSB connection to a micro:bit device.
  */
-export class MicrobitWebUSBConnectionImpl
+class MicrobitWebUSBConnectionImpl
   extends TypedEventTarget<DeviceConnectionEventMap>
   implements MicrobitWebUSBConnection
 {