Nightwatch parallel for two browser run only default for browserstack - nightwatch.js

Question

I have configured several test settings and I want to run parallel chrome and ie.
When I run
./node_modules/.bin/nightwatch --env chrome
test for chrome runs
./node_modules/.bin/nightwatch --env ie
test for ie runs
./node_modules/.bin/nightwatch --env ie,chrome
test for firefox runs (as I guess this run only default ones and nothing more)
Nightwatch 1.0.18
{
"src_folders": [
"test"
],
"output_folder": "reports",
"live_output" : true,
"custom_commands_path": "config/commands",
"test_runner": {
"type" : "mocha",
"options" : {
"grep": "#acc"
}
},
"test_settings": {
"default": {
"selenium_host": "hub-cloud.browserstack.com",
"selenium_port": 80,
"launch_url": "localhost",
"browserstack.key": "KEY",
"browserstack.user": "USER",
"browserstack.local": "true"
},
"chrome-local": {
"default_path_prefix": "",
"launch_url": "localhost",
"screenshots": {
"enabled": true,
"on_failure": true,
"on_success": true,
"on_error": true,
"path": "./screenshots"
},
"desiredCapabilities": {
"browserName": "chrome",
"javascriptEnabled": true,
"chromeOptions": {
"args": [
"--no-sandbox",
"headless",
"window-size=1920,1200"
]
},
"acceptSslCerts": true,
"acceptInsecureCerts": true,
"elementScrollBehavior": 1
}
},
"chrome": {
"desiredCapabilities": {
"browser": "chrome"
}
},
"ie": {
"desiredCapabilities": {
"browserName": "ie",
}
}
}
}

Answer 1

for running parallel tests using Nightwatch refer - https://github.com/browserstack/nightwatch-browserstack
As you need to run parallel tests on Chrome and IE browsers you need to make changes to the line https://github.com/browserstack/nightwatch-browserstack/blob/master/package.json#L10 as follows-
"parallel": "./node_modules/.bin/nightwatch -c conf/parallel.conf.js
-e ie,chrome"