language: php

php:
  - 7.1
  - 7.2
  - 7.3

env:
  - COMPOSER_FLAGS="--prefer-lowest"
  - COMPOSER_FLAGS=""

install:
  - php -v | grep '^PHP 7.[^3]' && pecl install weakref-beta || true
  - travis_retry composer self-update
  - travis_retry composer update ${COMPOSER_FLAGS} --no-interaction --prefer-source
  - nvm install stable
  - nvm use stable
  - npm install