add polyfill for new Web Bluetooth methods

src/utils/web-bluetooth.ts

@@ -0,0 +1,27 @@
+/**
+ * Current definition of BluetoothRemoteGATTCharacteristic doesn't include
+ * new Web Bluetooth APIs.
+ */
+export interface PolyfillBluetoothRemoteGATTCharacteristic
+    extends BluetoothRemoteGATTCharacteristic {
+    writeValueWithResponse(value: BufferSource): Promise<void>;
+    writeValueWithoutResponse(value: BufferSource): Promise<void>;
+}
+
+/**
+ * Fills in writeValueWithResponse and writeValueWithoutResponse for backward
+ * compatibility.
+ * @param char a remote GATT characteristic object
+ */
+export function polyfillBluetoothRemoteGATTCharacteristic(
+    char: BluetoothRemoteGATTCharacteristic,
+): PolyfillBluetoothRemoteGATTCharacteristic {
+    const polyfill = (char as unknown) as PolyfillBluetoothRemoteGATTCharacteristic;
+    if (!polyfill.writeValueWithResponse) {
+        polyfill.writeValueWithResponse = char.writeValue;
+    }
+    if (!polyfill.writeValueWithoutResponse) {
+        polyfill.writeValueWithoutResponse = char.writeValue;
+    }
+    return polyfill;
+}