Can't run Lightning Testing Service (LTS) for Salesforce - salesforce

Question

I have been using SFDX to automate Salesforce development for a little while now with Teamcity. SFDX doesn't always provide the best error messages but the documentation is usually very helpful. Well, or so I thought, until I started working with LTS. Here's the documentation to install LTS - https://developer.salesforce.com/docs/atlas.en-us.lightning.meta/lightning/lightning_testing_install.htm. I have read the docs and followed the instructions but I cannot get LTS to work for me. I am able to create a scratch org, and install LTS but I am not able to run the tests.
sfdx force:lightning:test:run -a jasmineTests.app
The following command allows you to run the sample Jasmin test. Whenever I try that command I get the following error:
ERROR running force:lightning:test:run: Unable to connect to selenium. In the documentation, it doesn't specify the server requiring selenium.
Although the docs don't mention anything about selenium, I have tried downloading selenium-standalone-chrome. I tried running selenium/standalone-chrome as a docker container. But it doesn't work.
Links tried:
https://github.com/forcedotcom/LightningTestingService/issues/46
https://github.com/forcedotcom/LightningTestingService/issues/46#issuecomment-457829523
https://github.com/forcedotcom/LightningTestingService/issues/46#issuecomment-347928851
Please help, I have tried almost everything.

Answer 1

You do need Selenium and its associated dependencies (browsers, etc) available in your container environment. Unfortunately, I don't believe any official images or dependency lists are available (and of course, the specific package names will vary by distro). I can tell you that I've had success using the circleci/openjdk:latest-node-browsers image to execute LTS tests in continuous integration.
I have a repository of Salesforce CI examples on GitHub, one of which is a working demo of LTS testing. In abbreviated form, it goes like this.
version: 2
jobs:
build:
docker:
- image: circleci/openjdk:latest-node-browsers
steps:
- checkout
- restore_cache:
keys:
- sfdx
- run:
name: Install Salesforce DX
command: |
if [ ! -d node_modules/sfdx-cli ]; then
export SFDX_AUTOUPDATE_DISABLE=true
export SFDX_USE_GENERIC_UNIX_KEYCHAIN=true
export SFDX_DOMAIN_RETRY=300
npm install sfdx-cli
node_modules/sfdx-cli/bin/run --version
node_modules/sfdx-cli/bin/run plugins --core
fi
- save_cache:
key: sfdx
paths:
- node_modules
- run:
name: Create Scratch Org
command: |
openssl aes-256-cbc -k $KEY -in assets/server.key.enc -out assets/server.key -d -md md5
node_modules/sfdx-cli/bin/run force:auth:jwt:grant --clientid $CONSUMERKEY --jwtkeyfile assets/server.key --username $USERNAME --setdefaultdevhubusername -a DevHub
node_modules/sfdx-cli/bin/run force:org:create -v DevHub -s -f config/project-scratch-def.json -a scratch
- run:
name: Remove Server Key
when: always
command: |
rm assets/server.key
- run:
name: Install Lightning Testing Service
command: |
node_modules/sfdx-cli/bin/run force:lightning:test:install -t jasmine
- run:
name: Push Source
command: |
node_modules/sfdx-cli/bin/run force:source:push -u scratch
- run:
name: Run Lightning Tests
command: |
mkdir ~/tests/lightning
node_modules/sfdx-cli/bin/run force:lightning:test:run -d ~/tests/lightning -r human -a lightningTests.app -o

Answer 2

Updating the answer in case anyone ever runs into this issue...
I got it to work! It turns out that the link I shared above was helpful after all LINK: https://github.com/forcedotcom/LightningTestingService/issues/46
I had to add a variable SELENIUM_REMOTE_URL=http://selenium:4444/wd/hub/ to TeamCity
And create a docker-compose.yml to start up selenium/standalone-chrome:latest
version: "3"
services:
selenium:
image: selenium/standalone-chrome:latest
ports:
- "4444:4444"