before_script.sh: update to match main repo

ci/travis/before_script.sh

@@ -9,3 +9,61 @@
 . "${TRAVIS_BUILD_DIR}/ci/travis/helpers.sh"
 
 header 'Running before_script.sh...'
+
+# https://github.com/rvm/rvm/pull/3627
+run rvm get head
+
+# unset rvm hook functions
+run unset -f cd gem
+
+# print all travis-defined environment variables
+run 'env | sort'
+
+# see https://github.com/travis-ci/travis-ci/issues/2666
+run export BRANCH_COMMIT="${TRAVIS_COMMIT_RANGE##*.}"
+run export TARGET_COMMIT="${TRAVIS_COMMIT_RANGE%%.*}"
+# shellcheck disable=SC2016
+if ! run 'MERGE_BASE="$(git merge-base "${BRANCH_COMMIT}" "${TARGET_COMMIT}")"'; then
+  run git fetch --unshallow
+  run 'MERGE_BASE="$(git merge-base "${BRANCH_COMMIT}" "${TARGET_COMMIT}")"'
+fi
+run export MERGE_BASE="${MERGE_BASE}"
+run export TRAVIS_COMMIT_RANGE="${MERGE_BASE}...${BRANCH_COMMIT}"
+
+# print detailed macOS version info
+run sw_vers
+
+# capture system ruby and gem locations
+run export SYSTEM_RUBY_HOME="/System/Library/Frameworks/Ruby.framework/Versions/${HOMEBREW_RUBY%.*}"
+run export SYSTEM_RUBY_BINDIR="${SYSTEM_RUBY_HOME}/usr/bin"
+run export SYSTEM_GEM_HOME="${SYSTEM_RUBY_HOME}/usr/lib/ruby/gems/${HOMEBREW_RUBY}"
+run export SYSTEM_GEM_BINDIR="${SYSTEM_GEM_HOME}/bin"
+
+# capture user gem locations
+run export GEM_HOME="$HOME/.gem/ruby/${HOMEBREW_RUBY}"
+run export GEM_BINDIR="${GEM_HOME}/bin"
+
+# ensure that the gems we install are used before system gems
+run export GEM_PATH="${GEM_HOME}:${SYSTEM_GEM_HOME}"
+run export PATH="${GEM_BINDIR}:${SYSTEM_GEM_BINDIR}:${SYSTEM_RUBY_BINDIR}:$PATH"
+
+# ensure that brew uses the ruby we want it to
+run export HOMEBREW_RUBY_PATH="${SYSTEM_RUBY_BINDIR}/ruby"
+
+run which ruby
+run ruby --version
+
+run which gem
+run gem --version
+
+run brew update
+
+# ensure that we are the only brew-cask available
+run brew uninstall --force brew-cask
+
+# mirror the repo as a tap, then run the build from there
+run export CASK_TAP_DIR="/usr/local/Library/Taps/${TRAVIS_REPO_SLUG}"
+run mkdir -p "${CASK_TAP_DIR}"
+run rsync -az --delete "${TRAVIS_BUILD_DIR}/" "${CASK_TAP_DIR}/"
+run export TRAVIS_BUILD_DIR="${CASK_TAP_DIR}"
+run cd "${CASK_TAP_DIR}" || exit 1