Implement the capability to change the language between tests

detox/src/devices/AndroidDriver.js

@@ -86,7 +86,7 @@ class AndroidDriver extends DeviceDriverBase {
     }
   }
 
-  async launch(deviceId, bundleId, launchArgs) {
+  async launch(deviceId, bundleId, launchArgs, language) {
     const args = [];
     _.forEach(launchArgs, (value, key) => {
       args.push(`${key} ${value}`);

detox/src/devices/AppleSimUtils.js

@@ -114,12 +114,12 @@ class AppleSimUtils {
     }
   }
 
-  async launch(udid, bundleId, launchArgs) {
+  async launch(udid, bundleId, launchArgs, language) {
     const frameworkPath = await environment.getFrameworkPath();
     const logsInfo = new LogsInfo(udid);
     const args = this._joinLaunchArgs(launchArgs);
 
-    const result = await this._launchMagically(frameworkPath, logsInfo, udid, bundleId, args);
+    const result = await this._launchMagically(frameworkPath, logsInfo, udid, bundleId, args, language);
     return this._parseLaunchId(result);
   }
 
@@ -243,17 +243,19 @@ class AppleSimUtils {
     return _.map(launchArgs, (v, k) => `${k} ${v}`).join(' ').trim();
   }
 
-  async _launchMagically(frameworkPath, logsInfo, udid, bundleId, args) {
+  async _launchMagically(frameworkPath, logsInfo, udid, bundleId, args, language) {
     const statusLogs = {
       trying: `Launching ${bundleId}...`,
       successful: `${bundleId} launched. The stdout and stderr logs were recreated, you can watch them with:\n` +
       `        tail -F ${logsInfo.absJoined}`
     };
 
+    const languageArgs = !!language ? `-AppleLanguages "(${language})" -AppleLocale ${language} ` : '';
+
     const launchBin = `/bin/cat /dev/null >${logsInfo.absStdout} 2>${logsInfo.absStderr} && ` +
       `SIMCTL_CHILD_DYLD_INSERT_LIBRARIES="${frameworkPath}/Detox" ` +
       `/usr/bin/xcrun simctl launch --stdout=${logsInfo.simStdout} --stderr=${logsInfo.simStderr} ` +
-      `${udid} ${bundleId} --args ${args}`;
+      `${udid} ${bundleId} ${languageArgs}--args ${args}`;;
 
     return await exec.execWithRetriesAndLogs(launchBin, undefined, statusLogs, 1);
   }

detox/src/devices/Device.js

@@ -112,7 +112,7 @@ class Device {
       bundleId: _bundleId,
     });
 
-    const processId = await this.deviceDriver.launch(this._deviceId, _bundleId, this._prepareLaunchArgs(baseLaunchArgs));
+    const processId = await this.deviceDriver.launch(this._deviceId, _bundleId, this._prepareLaunchArgs(baseLaunchArgs), params.language);
     this._processes[_bundleId] = processId;
 
     await this.deviceDriver.waitUntilReady();

detox/src/devices/Device.test.js

@@ -87,7 +87,19 @@ describe('Device', () => {
 
     expect(device.deviceDriver.launch).toHaveBeenCalledWith(device._deviceId,
       device._bundleId,
-      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test"});
+      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test"}, undefined);
+  });
+
+  it('launchApp({language}) should launch app with a specific language', async () => {
+    device = validDevice();
+
+    const language = 'es-MX';
+
+    await device.launchApp({language});
+
+    expect(device.deviceDriver.launch).toHaveBeenCalledWith(device._deviceId,
+      device._bundleId,
+      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test"}, language);
   });
 
   it('launchApp() should emit \'launchApp\' event for async listeners and wait for them', async () => {
@@ -163,7 +175,7 @@ describe('Device', () => {
     expect(device.deviceDriver.terminate).toHaveBeenCalled();
     expect(device.deviceDriver.launch).toHaveBeenCalledWith(device._deviceId,
       device._bundleId,
-      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test"});
+      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test"}, undefined);
   });
 
   it(`relaunchApp({newInstance: false}) should not terminate the app before launch`, async () => {
@@ -200,7 +212,7 @@ describe('Device', () => {
     expect(device.deviceDriver.installApp).toHaveBeenCalled();
     expect(device.deviceDriver.launch).toHaveBeenCalledWith(device._deviceId,
       device._bundleId,
-      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test"});
+      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test"}, undefined);
   });
 
   it(`relaunchApp() without delete when reuse is enabled should not uninstall and install`, async () => {
@@ -214,7 +226,7 @@ describe('Device', () => {
     expect(device.deviceDriver.installApp).not.toHaveBeenCalled();
     expect(device.deviceDriver.launch).toHaveBeenCalledWith(device._deviceId,
       device._bundleId,
-      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test"});
+      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test"}, undefined);
   });
 
   it(`relaunchApp() with url should send the url as a param in launchParams`, async () => {
@@ -223,7 +235,7 @@ describe('Device', () => {
 
     expect(device.deviceDriver.launch).toHaveBeenCalledWith(device._deviceId,
       device._bundleId,
-      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test", "-detoxURLOverride": "scheme://some.url"});
+      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test", "-detoxURLOverride": "scheme://some.url"}, undefined);
   });
 
   it(`relaunchApp() with url should send the url as a param in launchParams`, async () => {
@@ -235,7 +247,7 @@ describe('Device', () => {
       {
         "-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test", "-detoxURLOverride": "scheme://some.url", "-detoxSourceAppOverride":
         "sourceAppBundleId"
-      });
+      }, undefined);
   });
 
   it(`relaunchApp() with userNofitication should send the userNotification as a param in launchParams`, async () => {
@@ -247,7 +259,7 @@ describe('Device', () => {
 
     expect(device.deviceDriver.launch).toHaveBeenCalledWith(device._deviceId,
       device._bundleId,
-      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test", "-detoxUserNotificationDataURL": "url"});
+      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test", "-detoxUserNotificationDataURL": "url"}, undefined);
   });
 
   it(`relaunchApp() with url and userNofitication should throw`, async () => {
@@ -275,7 +287,7 @@ describe('Device', () => {
 
     expect(device.deviceDriver.launch).toHaveBeenCalledWith(device._deviceId,
       device._bundleId,
-      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test", "-arg1": "1", "-arg2": 2});
+      {"-detoxServer": "ws://localhost:8099", "-detoxSessionId": "test", "-arg1": "1", "-arg2": 2}, undefined);
   });
 
   it(`sendToHome() should pass to device driver`, async () => {

detox/src/devices/SimulatorDriver.js

@@ -82,8 +82,8 @@ class SimulatorDriver extends IosDriver {
     await this._applesimutils.uninstall(deviceId, bundleId);
   }
 
-  async launch(deviceId, bundleId, launchArgs) {
-    return await this._applesimutils.launch(deviceId, bundleId, launchArgs);
+  async launch(deviceId, bundleId, launchArgs, language) {
+    return await this._applesimutils.launch(deviceId, bundleId, launchArgs, language);
   }
 
   async terminate(deviceId, bundleId) {