add support for --network option to force usage of a specific network interface

lib/config.js

@@ -220,6 +220,11 @@ const config = convict({
 		doc: 'Do not flash firmware binaries',
 		format: Boolean,
 		default: false
+	},
+	network :{
+		doc: 'Force use of a specific network interface',
+		format: String,
+		default: ''
 	}
 });
 
@@ -278,6 +283,9 @@ Options:
 --dry
     Verify the configuration and skip all tests.
 
+--network=NETWORK
+	Force usage of a specific network interface ("wifi", "ethernet", "cellular")
+
 -v, --verbose
     Enable verbose logging.
 
@@ -326,7 +334,7 @@ function loadCliProfile() {
 // TODO: Describe command-specific arguments separately
 function parseCmdLine() {
 	return parseArgs(process.argv.slice(2), {
-		string: ['_', 'grep', 'config-file', 'test-dir', 'binary-dir', 'device-os-dir', 'target-dir', 'report-file'],
+		string: ['_', 'grep', 'config-file', 'test-dir', 'binary-dir', 'device-os-dir', 'target-dir', 'report-file', 'network'],
 		boolean: ['build', 'dry', 'fixtures', 'tags', 'combine', 'version', 'help', 'json', 'verbose', 'flash'],
 		default: {
 			'flash': true
@@ -464,6 +472,12 @@ function updateConfig(args) {
 	}
 	// Whether to build and flash firmware binaries
 	config.set('noFlash', !args['flash']);
+
+	// Forces usage of a specific network
+	const network = args['network'];
+	if (network) {
+		config.set('network', network);
+	}
 }
 
 function loadConfigFiles(args) {

lib/device.js

@@ -101,6 +101,13 @@ class Device extends EventEmitter {
 		if (param.clearBackupMemory) {
 			req.b = 1;
 		}
+		if (config.get('network')) {
+			switch (config.get('network')) {
+				case 'wifi': req.n = 'w'; break;
+				case 'ethernet': req.n = 'e'; break;
+				case 'cellular': req.n = 'c'; break;
+			}
+		}
 		await this._request(req);
 	}