Use newer versions of PHPUnit

[swissspidy]

WordPress core runs tests using PHPUnit 7, 6, or 4, depending on the PHP version:

https://github.com/WordPress/wordpress-develop/blob/1f1cf751e5130249ee06684399f001ae4479e650/.travis.yml#L62-L82

wp-dev-lib however uses PHPUnit 4 or 5, depending on PHP version:

wp-dev-lib/scripts/travis.install.sh

Lines 11 to 16 in d8207e7

	if [[ -z "$PHPUNIT_VERSION" ]]; then
	if [[ ${TRAVIS_PHP_VERSION:0:2} == "7." ]]; then
	PHPUNIT_VERSION='5.7'
	elif [[ ${TRAVIS_PHP_VERSION:0:3} != "5.2" ]]; then
	PHPUNIT_VERSION='4.8'
	fi

Is there any chance wp-dev-lib could use more up-to-date PHPUnit versions as well?

[kasparsd]

Could we require users to add the PHPUnit dependency to their project in composer.json instead?

A simple fix would be to check for an existing phpunit executable here before doing any install:

wp-dev-lib/scripts/travis.install.sh

Line 10 in d8207e7

if check_should_execute 'phpunit'; then

as we do here already:

wp-dev-lib/scripts/check-diff.sh

Line 454 in 90574b4

if check_should_execute 'phpunit' && ! command -v phpunit >/dev/null 2>&1; then

Thougts?

[kasparsd]

Actually, the whole thing here might no longer be necessary:

wp-dev-lib/scripts/travis.install.sh

Lines 10 to 27 in d8207e7

	if check_should_execute 'phpunit'; then
	if [[ -z "$PHPUNIT_VERSION" ]]; then
	if [[ ${TRAVIS_PHP_VERSION:0:2} == "7." ]]; then
	PHPUNIT_VERSION='5.7'
	elif [[ ${TRAVIS_PHP_VERSION:0:3} != "5.2" ]]; then
	PHPUNIT_VERSION='4.8'
	fi
	fi
	if [[ ! -z "$PHPUNIT_VERSION" ]]; then
	mkdir -p $HOME/phpunit-bin/$PHPUNIT_VERSION
	echo "Opting for phpunit $PHPUNIT_VERSION for PHP $TRAVIS_PHP_VERSION"
	export PATH="$HOME/phpunit-bin/$PHPUNIT_VERSION:$PATH"
	if [[ ! -e $HOME/phpunit-bin/$PHPUNIT_VERSION/phpunit ]]; then
	wget -O $HOME/phpunit-bin/$PHPUNIT_VERSION/phpunit https://phar.phpunit.de/phpunit-$PHPUNIT_VERSION.phar
	chmod +x $HOME/phpunit-bin/$PHPUNIT_VERSION/phpunit
	fi
	fi
	fi

since we're already installing PHPunit during install_tools:

wp-dev-lib/scripts/check-diff.sh

Lines 454 to 459 in 90574b4

	if check_should_execute 'phpunit' && ! command -v phpunit >/dev/null 2>&1; then
	PHPUNIT_VERSION=${PHPUNIT_VERSION:-5.7}
	echo "Downloading PHPUnit $PHPUNIT_VERSION phar"
	download https://phar.phpunit.de/phpunit-$PHPUNIT_VERSION.phar "$TEMP_TOOL_PATH/phpunit"
	chmod +x "$TEMP_TOOL_PATH/phpunit"
	fi

which runs right after:

wp-dev-lib/scripts/travis.install.sh

Line 30 in d8207e7

install_tools

[swissspidy]

@kasparsd Checking for an existing binary from composer makes sense to me. Adding that would be a nice enhancement still.