fix: stop executing avdmanager in case java is not available

In case JAVA_HOME is not set and there's no java executable in PATH, calls to `avdmanager` fail with error. However, on macOS this also leads to system prompt to install JAVA.
To handle this, do not execute `avdmanager` in case there's no JAVA_HOME or java in PATH.

Author: rosen-vladimirov

lib/common/declarations.d.ts

@@ -992,6 +992,18 @@ interface ISysInfo {
  	 */
 	getJavaCompilerVersion(): Promise<string>;
 
+	/**
+	 * Gets JAVA version based on the executable in PATH.
+	 * @return {Promise<string>}
+	 */
+	getJavaVersionFromPath(): Promise<string>;
+
+	/**
+	 * Gets JAVA version based on the JAVA from JAVA_HOME.
+	 * @return {Promise<string>}
+	 */
+	getJavaVersionFromJavaHome(): Promise<string>;
+
 	/**
 	 * Gets all global warnings for the current environment, for example Node.js version compatibility, OS compatibility, etc.
 	 * @return {Promise<ISystemWarning[]>} All warnings. Empty array is returned in case the system is setup correctly.

lib/common/mobile/android/android-virtual-device-service.ts

@@ -16,6 +16,7 @@ export class AndroidVirtualDeviceService implements Mobile.IAndroidVirtualDevice
 		private $emulatorHelper: Mobile.IEmulatorHelper,
 		private $fs: IFileSystem,
 		private $hostInfo: IHostInfo,
+		private $sysInfo: ISysInfo,
 		private $logger: ILogger) {
 		this.androidHome = process.env.ANDROID_HOME;
 	}
@@ -152,8 +153,12 @@ export class AndroidVirtualDeviceService implements Mobile.IAndroidVirtualDevice
 		let result: ISpawnResult = null;
 		let devices: Mobile.IDeviceInfo[] = [];
 		let errors: string[] = [];
+		const canExecuteAvdManagerCommand = await this.canExecuteAvdManagerCommand();
+		if (!canExecuteAvdManagerCommand) {
+			errors = ["Unable to execute avdmanager, ensure JAVA_HOME is set and points to correct directory"];
+		}
 
-		if (this.pathToAvdManagerExecutable && this.$fs.exists(this.pathToAvdManagerExecutable)) {
+		if (canExecuteAvdManagerCommand) {
 			result = await this.$childProcess.trySpawnFromCloseEvent(this.pathToAvdManagerExecutable, ["list", "avds"]);
 		} else if (this.pathToAndroidExecutable && this.$fs.exists(this.pathToAndroidExecutable)) {
 			result = await this.$childProcess.trySpawnFromCloseEvent(this.pathToAndroidExecutable, ["list", "avd"]);
@@ -169,6 +174,22 @@ export class AndroidVirtualDeviceService implements Mobile.IAndroidVirtualDevice
 		return { devices, errors };
 	}
 
+	@cache()
+	private async canExecuteAvdManagerCommand(): Promise<boolean> {
+		let canExecute = false;
+		if (this.pathToAvdManagerExecutable && this.$fs.exists(this.pathToAvdManagerExecutable)) {
+			if (process.env.JAVA_HOME) {
+				// In case JAVA_HOME is set, but it points to incorrect directory (i.e. there's no java in $JAVA_HOME/bin/java), avdmanager will fail
+				// no matter if you have correct java in PATH.
+				canExecute = !!(await this.$sysInfo.getJavaVersionFromJavaHome());
+			} else {
+				canExecute = !!(await this.$sysInfo.getJavaVersionFromPath());
+			}
+		}
+
+		return canExecute;
+	}
+
 	private async getRunningEmulatorData(runningEmulatorId: string, availableEmulators: Mobile.IDeviceInfo[]): Promise<Mobile.IDeviceInfo> {
 		const imageIdentifier = await this.getRunningEmulatorImageIdentifier(runningEmulatorId);
 		const runningEmulator = this.$emulatorHelper.getEmulatorByImageIdentifier(imageIdentifier, availableEmulators);

lib/common/test/unit-tests/mobile/android-virtual-device-service.ts

@@ -76,6 +76,10 @@ function createTestInjector(data: { avdManagerOutput?: string, avdManagerError?:
 	testInjector.register("emulatorHelper", EmulatorHelper);
 	testInjector.register("hostInfo", {});
 	testInjector.register("logger", { trace: () => ({}) });
+	testInjector.register("sysInfo", {
+		getJavaVersionFromJavaHome: async () => "1.8.0",
+		getJavaVersionFromPath: async () => "1.8.0"
+	});
 
 	return testInjector;
 }

lib/sys-info.ts

@@ -34,6 +34,14 @@ export class SysInfo implements ISysInfo {
 		return sysInfo.getJavaCompilerVersion();
 	}
 
+	public getJavaVersionFromPath(): Promise<string> {
+		return sysInfo.getJavaVersionFromPath();
+	}
+
+	public getJavaVersionFromJavaHome(): Promise<string> {
+		return sysInfo.getJavaVersionFromJavaHome();
+	}
+
 	@exported("sysInfo")
 	public async getSystemWarnings(): Promise<ISystemWarning[]> {
 		const warnings: ISystemWarning[] = [];