writeValue - options improvements (#20)

* improved write value options and added type param

* updated readme for writeValue

* WriteValue method improved  for backward compatible

README.md

@@ -166,7 +166,7 @@ const {bluetooth, destroy} = createBluetooth()
 | `Promise<String[]> getFlags()` | Defines how the characteristic value can be used. |
 | `Promise<bool> isNotifying()` | True, if notifications or indications on this characteristic are currently enabled. |
 | `Promise<Buffer> readValue(Number offset = 0)` | Issues a request to read the value of the characteristic and returns the value if the operation was successful. |
-| `Promise<void> writeValue(Buffer buffer, Number offset = 0)` | Issues a request to write the value of the characteristic. |
+| `Promise<void> writeValue(Buffer buffer, Number | WriteValueOptions options = {})` | Issues a request to write the value of the characteristic. Default options `{ offset: 0, type: 'reliable' }`. |
 | `Promise<void> startNotifications()` | Starts a notification session from this characteristic if it supports value notifications or indications. |
 | `Promise<void> stopNotifications()` | This method will cancel any previous StartNotify transaction. |
 | `Promise<String> toString()` | User friendly characteristic name. |

src/GattCharacteristic.js

@@ -33,16 +33,21 @@ class GattCharacteristic extends EventEmitter {
     return Buffer.from(payload)
   }
 
-  async writeValue (value, offset = 0) {
+  async writeValue (value, optionsOrOffset = {}) {
     if (!Buffer.isBuffer(value)) {
       throw new Error('Only buffers can be wrote')
     }
-    const options = {
-      offset: buildTypedValue('uint16', offset),
-      type: buildTypedValue('string', 'reliable')
+
+    const options = typeof optionsOrOffset === 'number' ? { offset: optionsOrOffset } : optionsOrOffset
+    const mergedOptions = Object.assign({ offset: 0, type: 'reliable' }, options)
+
+    const callOptions = {
+      offset: buildTypedValue('uint16', mergedOptions.offset),
+      type: buildTypedValue('string', mergedOptions.type)
     }
+
     const { data } = value.toJSON()
-    await this.helper.callMethod('WriteValue', data, options)
+    await this.helper.callMethod('WriteValue', data, callOptions)
   }
 
   async startNotifications () {

src/index.d.ts

@@ -6,7 +6,7 @@ declare namespace NodeBle {
         getFlags(): Promise<string[]>;
         isNotifying(): Promise<boolean>;
         readValue(offset?: number): Promise<Buffer>;
-        writeValue(buffer: Buffer, offset?: number): Promise<void>;
+        writeValue(buffer: Buffer, optionsOrOffset?: number | WriteValueOptions): Promise<void>;
         startNotifications(): Promise<void>;
         stopNotifications(): Promise<void>;
         toString(): Promise<string>;
@@ -75,6 +75,11 @@ declare namespace NodeBle {
         destroy(): void;
         bluetooth: Bluetooth;
     };
+
+    interface WriteValueOptions {
+        offset?: number;
+        type?: 'reliable' | 'request' | 'command';
+    }
 }
 
 export = NodeBle;

test/GattCharacteristic.spec.js

@@ -16,6 +16,7 @@ jest.doMock('../src/BusHelper', () => {
     }
   }
 })
+const buildTypedValue = require('../src/buildTypedValue')
 const GattCharacteristic = require('../src/GattCharacteristic')
 const dbus = Symbol('dbus')
 
@@ -35,10 +36,26 @@ test('props', async () => {
 
 test('read/write', async () => {
   const characteristic = new GattCharacteristic(dbus, 'hci0', 'dev_00_00_00_00_00_00', 'characteristic0006', 'char008')
+  const writeValueOptions = (offset = 0, type = 'reliable') => {
+    return { offset: buildTypedValue('uint16', offset), type: buildTypedValue('string', type) }
+  }
 
   await expect(characteristic.writeValue('not_a_buffer')).rejects.toThrow('Only buffers can be wrote')
+
+  await expect(characteristic.writeValue(Buffer.from('hello'), 5)).resolves.toBeUndefined()
+  expect(characteristic.helper.callMethod).toHaveBeenCalledWith('WriteValue', expect.anything(), writeValueOptions(5))
+
   await expect(characteristic.writeValue(Buffer.from('hello'))).resolves.toBeUndefined()
-  expect(characteristic.helper.callMethod).toHaveBeenCalledWith('WriteValue', expect.anything(), expect.anything())
+  expect(characteristic.helper.callMethod).toHaveBeenCalledWith('WriteValue', expect.anything(), writeValueOptions())
+
+  await expect(characteristic.writeValue(Buffer.from('hello'), { type: 'command' })).resolves.toBeUndefined()
+  expect(characteristic.helper.callMethod).toHaveBeenCalledWith('WriteValue', expect.anything(), writeValueOptions(0, 'command'))
+
+  await expect(characteristic.writeValue(Buffer.from('hello'), { offset: 9, type: 'request' })).resolves.toBeUndefined()
+  expect(characteristic.helper.callMethod).toHaveBeenCalledWith('WriteValue', expect.anything(), writeValueOptions(9, 'request'))
+
+  await expect(characteristic.writeValue(Buffer.from('hello'), 'incorrect argument')).resolves.toBeUndefined()
+  expect(characteristic.helper.callMethod).toHaveBeenCalledWith('WriteValue', expect.anything(), writeValueOptions())
 
   characteristic.helper.callMethod.mockResolvedValueOnce([255, 100, 0])
   await expect(characteristic.readValue()).resolves.toEqual(Buffer.from([255, 100, 0]))