TravisCI + Polymer2 element config files

.travis.yml

language: node_js
sudo: false
node_js: stable
addons:
  firefox: latest
  chrome: stable
dist: trusty

install:
  - npm i -g bower polymer-cli
  - npx polymer install
before_script:
  - npm i -g eslint eslint-config-google eslint-plugin-chai-expect eslint-plugin-html
  - npm run lint
script:
  - npm run test
  - if [ "${TRAVIS_BRANCH}" = "master" ] && [ "${TRAVIS_PULL_REQUEST}" = "false" ]; then npm run test:sauce; fi

notifications:
  email:
    on_success: never
    on_failure: always

package.json

{
  "scripts": {
    "lint": "npm run lint:javascript && npx polymer lint",
    "lint:javascript": "npx eslint . --ext js,html --ignore-path .gitignore",
    "test": "npx polymer test",
    "test:sauce": "npx polymer test --plugin sauce"
  }
}

wct.conf.json

{
  "plugins": {
    "local": {
      "browserOptions": {
        "chrome": [
          "headless",
          "disable-gpu",
          "no-sandbox"
        ],
        "firefox": [
          "-headless"
        ]
      }
    }
  }
}