Gradle task for launching Android simulator

Android build toolchain, albeit being powerful, sometimes lacks some essential functionality required for the modern software development. In particular, running instrumented unit-tests in the CI environment: those tests require a device or a simulator running, however developers need some scripting to make it work.

To simplify the task, I've created a Gradle task that verifies if any Android device or simulator is connected. If not, the task launches a simulator with the first AVD in the list (or fails if no AVDs are found). It's up to you to make the dependencies for the connectedCheck task. The sample output:

> ./gradlew connect --info

...

:AndroidSampleApp:connect (Thread[main,5,main]) started.
:AndroidSampleApp:connect
Executing task ':AndroidSampleApp:connect' (up-to-date check took 0.001 secs) due to:
  Task has not declared any outputs.
Detecting devices...
Launching emulator for Nexus_5_API_25 ...
:AndroidSampleApp:connect (Thread[main,5,main]) completed. Took 14.186 secs.

BUILD SUCCESSFUL

The code (just add it into the build.gradle of the module):

	apply plugin: 'com.android.application'
	task connect(type: ConnectDevicesTask) {
	description 'Verifies that any Android device is connected and runs a simulator if not.'
	}
	import com.android.ddmlib.AndroidDebugBridge
	import com.android.ddmlib.IDevice
	import org.gradle.tooling.BuildException
	class ConnectDevicesTask extends DefaultTask {
	@TaskAction
	void connect() {
	project.logger.info "Detecting devices..."
	AndroidDebugBridge.initIfNeeded false /*clientSupport*/
	AndroidDebugBridge bridge = AndroidDebugBridge.createBridge(
	project.android.adbExe.absolutePath,
	false /*forceNewBridge*/
	)
	long timeOut = 30000 // 30 sec
	int sleepTime = 1000
	while (!bridge.hasInitialDeviceList() && timeOut > 0) {
	sleep sleepTime
	timeOut -= sleepTime
	}
	if (timeOut <= 0 && !bridge.hasInitialDeviceList) {
	throw new BuildException("Timeout getting device list.", null)
	}
	IDevice[] devices = bridge.devices
	if (devices.length == 0) {
	String emulator = project.android.sdkDirectory.absolutePath + "/tools/emulator"
	String command = "$emulator -list-avds"
	String avds = command.execute().text
	if (avds?.trim()) {
	String avd = avds.split()[0]
	String runCmd = "$emulator -avd $avd"
	project.logger.info "Launching emulator for $avd ..."
	runCmd.execute()
	timeOut = 30000 // 30 sec
	while (bridge.devices.length == 0 && timeOut > 0) {
	sleep sleepTime
	timeOut -= sleepTime
	}
	if (bridge.devices.length == 0 && timeOut <= 0) {
	throw new BuildException("Timeout launching the emulator.", null)
	}
	} else {
	throw new BuildException("No registered AVDs!", null)
	}
	}
	}
	}

view raw build.gradle hosted with ❤ by GitHub