appium/packages/base-driver/lib/protocol

webdriver and mobile-json-wire protocols

An abstraction of the Mobile JSON Wire Protocol (spec) and the W3C Wire Protocol (spec with Appium extensions (as specified here).

Protocol Detection

In the event that a session is requested, and both MJSONWP and W3C capabilities are provided, like this

{
  "capabilities: {
    "alwaysMatch": {...}, 
    "firstMatch": [{...}, ...]
  },
  "desiredCapabilities": {...}
}

a W3C session will be served unless the W3C Capabilities are incomplete. So if the "desiredCapabilities" object has more keys then whatever the capabilities were matched for the W3C capabilities, then an MJSONWP session will be served instead

Endpoints in the protocol

The Mobile JSON Wire Protocol package gives access to a number of endpoints documented here.

The W3C WebDriver Protocol package gives access to a number of endpoints documented in the official documentation and the simplified spec

Protocol

The basic class, subclassed by drivers that will use the protocol.

routeConfiguringFunction (driver)

This function gives drivers access to the protocol routes. It returns a function that itself will take an Express application.

isSessionCommand (command)

Checks if the command needs to have a session associated with it.

ALL_COMMANDS

An array of all the commands that will be dispatched to by the Mobile JSON Wire Proxy endpoints.

NO_SESSION_ID_COMMANDS

An array of commands that do not need a session associated with them.

Errors

This package exports a number of classes and methods related to Selenium error handling. There are error classes for each Selenium error type (see JSONWP Errors, as well as the context errors in the mobile spec.

The list of errors, and their meanings, can be found here for JSONWP and here for W3C Errors)

There are, in addition, two helper methods for dealing with errors

isErrorType (err, type)

• checks if the err object is a Mobile JSON Wire Protocol error of a particular type
• arguments
  • err - the error object to test
  • type - the error class to test against
• usage

  import { errors, isErrorType } from 'mobile-json-wire-protocol';
  
  try {
    // do some stuff...
  } catch (err) {
    if (isErrorType(err, errors.InvalidCookieDomainError)) {
      // process...
    }
  }
  

errorFromCode (code, message)

• retrieve the appropriate error for an error code, with the supplied message.
• arguments
  • code - the integer error code for a Mobile JSON Wire Protocol error
  • message - the message to be encapsulated in the error
• usage

  import { errors, errorFromCode } from 'mobile-json-wire-protocol';
  
  let error = errorFromCode(6, 'an error has occurred');
  
  console.log(error instanceof errors.NoSuchDriverError);
  // => true
  
  console.log(error.message === 'an error has occurred');
  // => true