add mobile logs broadcast

[KazuCocoa]

Include "appium-base-driver": "^2.27.0"

[debug] [W3C] Calling AppiumDriver.getStatus() with args: []
[debug] [W3C] Responding to client with driver.getStatus() result: {"build":{"version":"1.8.0-beta","revision":"228ca6b3285b718b65c78d03d4b2170189145c5c"}}
[HTTP] <-- GET /wd/hub/status 200 58 ms - 98
[HTTP]
[HTTP] --> POST /wd/hub/session/b3d32a41-31f9-493b-803d-47c16b724f46/execute
[HTTP] {"script":"mobile: stopLogsBroadcast","args":[]}
[debug] [W3C] Calling AppiumDriver.execute() with args: ["mobile: stopLogsBroadcast",[],"b3d32a41-31f9-493b-803d-47c16b724f46"]
[W3C] Encountered internal error running command: TypeError: Cannot read property 'getWebSocketHandlers' of undefined
[W3C]     at AndroidDriver.callee$0$0$ (/Users/kazuaki/GitHub/appium/node_modules/appium-android-driver/lib/commands/log.js:105:35)
[W3C]     at tryCatch (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:67:40)
[W3C]     at GeneratorFunctionPrototype.invoke [as _invoke] (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:315:22)
[W3C]     at GeneratorFunctionPrototype.prototype.(anonymous function) [as next] (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:100:21)
[W3C]     at invoke (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:136:37)
[W3C]     at enqueueResult (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:185:17)
[W3C]     at new Promise (<anonymous>)
[W3C]     at new F (/Users/kazuaki/GitHub/appium/node_modules/core-js/library/modules/$.export.js:30:36)
[W3C]     at AsyncIterator.enqueue (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:184:12)
[W3C]     at AsyncIterator.prototype.(anonymous function) [as next] (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:100:21)
[W3C]     at Object.runtime.async (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:209:12)
[W3C]     at AndroidDriver.callee$0$0 [as mobileStopLogsBroadcast] (/Users/kazuaki/GitHub/appium/node_modules/appium-android-driver/build/lib/commands/log.js:186:30)
[W3C]     at AndroidDriver.callee$0$0$ (/Users/kazuaki/GitHub/appium/node_modules/appium-android-driver/lib/commands/execute.js:26:58)
[W3C]     at tryCatch (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:67:40)
[W3C]     at GeneratorFunctionPrototype.invoke [as _invoke] (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:315:22)
[W3C]     at GeneratorFunctionPrototype.prototype.(anonymous function) [as next] (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:100:21)
[W3C]     at invoke (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:136:37)
[W3C]     at enqueueResult (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:185:17)
[W3C]     at new Promise (<anonymous>)
[W3C]     at new F (/Users/kazuaki/GitHub/appium/node_modules/core-js/library/modules/$.export.js:30:36)
[W3C]     at AsyncIterator.enqueue (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:184:12)
[W3C]     at AsyncIterator.prototype.(anonymous function) [as next] (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:100:21)
[W3C]     at Object.runtime.async (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:209:12)
[W3C]     at AndroidDriver.callee$0$0 [as executeMobile] (/Users/kazuaki/GitHub/appium/node_modules/appium-android-driver/build/lib/commands/execute.js:48:30)
[W3C]     at AndroidDriver.callee$0$0$ (/Users/kazuaki/GitHub/appium/node_modules/appium-android-driver/lib/commands/execute.js:9:23)
[W3C]     at tryCatch (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:67:40)
[W3C]     at GeneratorFunctionPrototype.invoke [as _invoke] (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:315:22)
[W3C]     at GeneratorFunctionPrototype.prototype.(anonymous function) [as next] (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:100:21)
[W3C]     at invoke (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:136:37)
[W3C]     at enqueueResult (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:185:17)
[W3C]     at new Promise (<anonymous>)
[W3C]     at new F (/Users/kazuaki/GitHub/appium/node_modules/core-js/library/modules/$.export.js:30:36)
[W3C]     at AsyncIterator.enqueue (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:184:12)
[W3C]     at AsyncIterator.prototype.(anonymous function) [as next] (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:100:21)
[W3C]     at Object.runtime.async (/Users/kazuaki/GitHub/appium/node_modules/babel-runtime/regenerator/runtime.js:209:12)
[W3C]     at AndroidDriver.callee$0$0 [as execute] (/Users/kazuaki/GitHub/appium/node_modules/appium-android-driver/build/lib/commands/execute.js:20:30)
[W3C]     at /Users/kazuaki/GitHub/appium/node_modules/appium-base-driver/lib/basedriver/driver.js:275:26
[W3C]     at tryCatcher (/Users/kazuaki/GitHub/appium/node_modules/bluebird/js/main/util.js:26:23)
[W3C]     at Promise._settlePromiseFromHandler (/Users/kazuaki/GitHub/appium/node_modules/bluebird/js/main/promise.js:510:31)
[W3C]     at Promise._settlePromiseAt (/Users/kazuaki/GitHub/appium/node_modules/bluebird/js/main/promise.js:584:18)
[W3C]     at Promise._settlePromiseAtPostResolution (/Users/kazuaki/GitHub/appium/node_modules/bluebird/js/main/promise.js:248:10)
[W3C]     at Async._drainQueue (/Users/kazuaki/GitHub/appium/node_modules/bluebird/js/main/async.js:128:12)
[W3C]     at Async._drainQueues (/Users/kazuaki/GitHub/appium/node_modules/bluebird/js/main/async.js:133:10)
[W3C]     at Immediate.Async.drainQueues (/Users/kazuaki/GitHub/appium/node_modules/bluebird/js/main/async.js:15:14)
[W3C]     at runCallback (timers.js:773:18)
[W3C]     at tryOnImmediate (timers.js:734:5)
[W3C]     at processImmediate [as _immediateCallback] (timers.js:711:5)
[HTTP] <-- POST /wd/hub/session/b3d32a41-31f9-493b-803d-47c16b724f46/execute 500 11 ms - 227
[HTTP]
^C[Appium] Received SIGINT - shutting down

[mykola-mokhnach]

I see the actual implementation like an additional webdriver feature, which allows it to emit signals (logcat messages in our case), which can then be asynchronously handled by one or multiple clients (depending on which type of signal listener(s) they define). The basic example: https://github.com/fnando/signal

In the future this can be extended to any type of signal if we add more web socket types.

[KazuCocoa]

a note for me : appium/java-client#858