Create connection

As explained before, each USB device can have multiple interfaces for different functions, and each interface needs to be exclusively claimed by programs.

Requesting permission to access a device doesn't automatically claim its interfaces. The connect method does that, but not only that. It includes three steps to simplify the usage:

1. Call WebUSB USBDevice#open method to open the device
2. Call WebUSB USBDevice#claimInterface method to claim the ADB interface
3. Find the endpoints for the ADB interface and create streams for them

It returns a pair of streams, one for sending and one for receiving ADB packets.

JavaScript

const connection = await device.connect();
export {};

TypeScript

import type { AdbPacketData, AdbPacketInit } from "@yume-chan/adb";
import type { Consumable, ReadableWritablePair } from "@yume-chan/stream-extra";

const connection: ReadableWritablePair<
  AdbPacketData,
  Consumable<AdbPacketInit>
> = await device.connect();

If the interface is already claimed by another program (or another USBDevice instance), connect will throw an NetworkError. You can catch it and show a message to the user to ask them to close the conflicting program.

JavaScript

function connect(device) {
  try {
    return await device.connect();
  } catch (error) {
    // `usb` package for Node.js doesn't throw a real `DOMException`
    // This check is compatible with both Chrome and `usb` package
    if (
      typeof error === "object" &&
      error !== null &&
      "name" in error &&
      error.name === "NetworkError"
    ) {
      alert(
        "The device is already in use by another program. Please close the program and try again.",
      );
    }
    throw error;
  }
}

TypeScript

function connect(device: AdbDaemonWebUsbDevice) {
  try {
    return await device.connect();
  } catch (error) {
    // `usb` package for Node.js doesn't throw a real `DOMException`
    // This check is compatible with both Chrome and `usb` package
    if (
      typeof error === "object" &&
      error !== null &&
      "name" in error &&
      error.name === "NetworkError"
    ) {
      alert(
        "The device is already in use by another program. Please close the program and try again.",
      );
    }
    throw error;
  }
}

Next Step

Create credential store