DX improvements in new monorepo

[thelovekesh]

As per #654, we are moving published modules as standalone plugins, making the current repo a mono repo for multiple plugins.

This brings a new challenge to streamline the current tooling and build setup used to maintain coding standards, testing, and publishing the plugin. With this, we are exploring integrating existing workflows in such a way that it doesn't hurt the DX and keeps the maintenance cost low.

Tasklist

• [Done] PHPCS setup for mono repo Separate phpcs.xml.dist Files for Each Plugin to Isolate Text Domains #997 (Separate phpcs.xml.dist Files for Each Plugin to Isolate Text Domains #1002)
• Setup PHPUnit on plugin level instead of testsuite in main PHPUnit config(See: Introduce plugins folder for standalone plugins #934 (comment) and Introduce plugins folder for standalone plugins #934 (comment)). Testsuite-based setup was introduced in Add test suite for Plugins folder #956.
• [Done] Reconsider build setup for both main and standalone plugins. Currently, we use a custom CLI tool which often requires tuning on a use case basis which can be replaced with a tool like Webpack with build steps for each use case. (Update plugin(s) build setup for distribution #1033)

[thelovekesh]

But assuming that the tests all remain in /tests and don't also move to the /plugins directory, there would still need to be a plugin-specific testsuite in the plugin's dedicated phpunit.xml.dist: from (#934 (comment))

@westonruter I think it would make more sense to include the plugin test in the plugin directory itself. It will help us in multiple ways:

• With this new approach, we won't need to switch between directories or hunt down related files scattered throughout multiple directories.

• When a plugin becomes part of the core, removing it is much easier. Simply delete the dedicated directory, and there's no need for a tedious search and delete across the entire plugin.

• No need to modify configurations based on changes in the plugins/ directory.

• This new approach ensures a smooth testing experience with just one command for any plugin.

  ./vendor/bin/phpunit -c plugins/foo/phpunit.xml.dist # Run tests for plugin: Foo 
  ./vendor/bin/phpunit -c plugins/bar/phpunit.xml.dist # Run tests for plugin: Bar

Please take a look at the POC - #1013

[westonruter]

I do like the idea of organizing the tests into the plugin's directory. It's more helpful for DX to keep the plugin-related code together than it is to keep all test-related code together.

[felixarntz]

+1 on the idea to keep the plugin's source and test code in a similar location. For example, a plugin plugins/auto-sizes could have its tests in a plugins/auto-sizes/tests directory. This should be relatively straightforward and we would just need to ensure the tests folder is omitted from the standalone plugin builds.

What I'm not a fan of is the separate phpunit.xml.dist files. What's the benefit of that? A partial reason for not going with individual files is to ease maintenance, I don't see a benefit of having the almost identical PHPUnit config file duplicated for every plugin in the monorepo. IMO it's easier from a maintenance perspective to have a single file, and add the test suite for a new plugin once it's added. It's a one-and-done situation, and there are already other places in the overall codebase anyway that need to be touched for administrative purposes in this scenario (e.g. the .github/CODEOWNERS file).

So from my end:

• +1 to putting the actual tests (the PHP files) together with the standalone plugins
• -1 to having an individual PHPUnit config file for each plugin

[westonruter]

@felixarntz A benefit to having a separate phpunit.xml.dist file for each plugin, which I @thelovekesh first shared in #934 (comment), is that the test suite would no longer be bound 1:1 to the plugin. A plugin could benefit from having multiple test suites. For example, there could be an external-http test suite for a given plugin which is slower. Nevertheless, the bootstrap logic is currently bound up with the test suite name being exactly the same as the slug for the standalone plugin. So if a new test suite is needed for a plugin, this bootstrapping logic wouldn't work anymore. By locating the phpunit.xml.dist in each plugin's respective directory, there wouldn't be any more need for hacking the --testsuite arg.

performance/tests/bootstrap.php

Lines 37 to 90 in 082a106

	// Check if we use the plugin's test suite. If so, disable the PL plugin and only load the requested plugin.
	$plugin_name = '';
	foreach ( $_SERVER['argv'] as $index => $arg ) {
	if (
	'--testsuite' === $arg &&
	isset( $_SERVER['argv'][ $index + 1 ] ) &&
	'performance-lab' !== $_SERVER['argv'][ $index + 1 ] &&
	file_exists( TESTS_PLUGIN_DIR . '/plugins/' . $_SERVER['argv'][ $index + 1 ] )
	) {
	$plugin_name = $_SERVER['argv'][ $index + 1 ];
	}
	}
	if ( $plugin_name ) {
	$plugin_test_path = TESTS_PLUGIN_DIR . '/plugins/' . $plugin_name;
	tests_add_filter(
	'plugins_loaded',
	static function () use ( $plugin_test_path, $plugin_name ) {
	// Check if plugin has a "plugin/plugin.php" file.
	if ( file_exists( $plugin_test_path . '/' . $plugin_name . '.php' ) ) {
	require_once $plugin_test_path . '/' . $plugin_name . '.php';
	} elseif ( file_exists( $plugin_test_path . '/load.php' ) ) {
	// Check if plugin has a "plugin/load.php" file.
	require_once $plugin_test_path . '/load.php';
	} else {
	echo "Unable to locate standalone plugin bootstrap file in $plugin_test_path.";
	exit( 1 );
	}
	},
	1
	);
	} else {
	// Force plugin to be active.
	$GLOBALS['wp_tests_options'] = array(
	'active_plugins' => array( basename( TESTS_PLUGIN_DIR ) . '/load.php' ),
	);
	// Add filter to ensure the plugin's admin integration and all modules are loaded for tests.
	tests_add_filter(
	'plugins_loaded',
	static function () {
	require_once TESTS_PLUGIN_DIR . '/admin/load.php';
	require_once TESTS_PLUGIN_DIR . '/admin/server-timing.php';
	require_once TESTS_PLUGIN_DIR . '/admin/plugins.php';
	$module_files = glob( TESTS_PLUGIN_DIR . '/modules/*/*/load.php' );
	if ( $module_files ) {
	foreach ( $module_files as $module_file ) {
	require_once $module_file;
	}
	}
	},
	1
	);
	}

The standalone plugins can still share the bootstrapping logic as I mentioned in #1013 (comment) while they each have their own phpunit.xml.dist.

[felixarntz]

@westonruter I'm not sure the value is worth the tradeoff. I can't envision a single plugin would use multiple test suites. Certainly there are a few complex plugins that may make use of that, but we haven't used it so far, and I'm not sure when or why we would.

While for PHPCS I see a benefit of individual files because of minor configuration changes, for PHPUnit the config files typically look the same for every plugin. I'd say we should reevaluate this if we encounter a real need for it, but otherwise it creates overhead of duplicate files without a real benefit.

[westonruter]

@felixarntz The Embed Optimizer plugin could, for example, have an external-http test suite that pulls down oEmbed data from each of the providers rather than using fixtures. I suppose that could also be achieved with an environment variable.

Another benefit is the DX improvement. If you're working on Speculation Rules, you could just run phpunit right from the /plugins/speculation-rules plugin and it would just run the tests for that plugin. Otherwise, you'd have to do phpunit --testsuite speculation-rules, or if using our NPM wrappers, in reality you'd have to do the very unergonomic:

npm run test-php -- -- -- --testsuite=speculation-rules

[felixarntz]

@westonruter

The Embed Optimizer plugin could, for example, have an external-http test suite that pulls down oEmbed data from each of the providers rather than using fixtures. I suppose that could also be achieved with an environment variable.

Again, IMO this is a theoretical benefit as we have no plans to make use of it at this point. If there is a need for it, we could re-evaluate. But as you're saying there may be more efficient ways to achieve it than duplicating the config files.

Another benefit is the DX improvement. If you're working on Speculation Rules, you could just run phpunit right from the /plugins/speculation-rules plugin and it would just run the tests for that plugin.

Would that use the correct PHPUnit version (the one locally installed via PL composer.json)? Given you wouldn't be in the directory that has composer.json and vendor, I'm not 100% sure about it.

Otherwise, you'd have to do phpunit --testsuite speculation-rules, or if using our NPM wrappers, in reality you'd have to do the very unergonomic:

npm run test-php -- -- -- --testsuite=speculation-rules

Wouldn't we be able to simplify the call using our NPM wrappers? #1002 already adds a wrapper to simplify this for e.g. auto-sizes, so we could do that here too.

[westonruter]

Would that use the correct PHPUnit version (the one locally installed via PL composer.json)? Given you wouldn't be in the directory that has composer.json and vendor, I'm not 100% sure about it.

That's true. Although that can be easily resolved with a shell script that sets up the environment to work on the project. Someone could just add this to their .bashrc:

function workhere() {
    export PATH="$PATH:$(pwd)/vendor/bin"
}

And then when navigating to the performance repo do:

$ workhere

And then the phpunit command would be scoped to the project.

Interestingly, PhpStorm (er, IntelliJ) does this automatically for Node scripts. (VSCode does not currently implement this.) When I'm in the built-in IDE terminal, I see my $PATH is includes ~/repos/performance/node_modules/.bin. So I can actually skip doing npm run wp-env or npx wp-env and just do wp-env. (Good to know!) Interestingly, PhpStorm does not implement this also for Composer. (But I just filed a feature request.)

Wouldn't we be able to simplify the call using our NPM wrappers? #1002 already adds a wrapper to simplify this for e.g. auto-sizes, so we could do that here too.

True. Although the need to pass -- -- -- in order to send args to PHPUnit remains, for example to add --filter or --group. Also, the npm wrappers add additional latency and noise to running commands, so it would be nice if we didn't have to use them.

[thelovekesh]

A partial reason for not going with individual files is to ease maintenance, I don't see a benefit of having the almost identical PHPUnit config file duplicated for every plugin in the monorepo.

TBH the testsuite approach looks like having more maintenance cost. Why?

• Modifying the main config for individual plugin tests becomes cumbersome as the number of plugins grows. Also adding/removing entries in the testsuites section becomes repetitive for every plugin addition/removal.
• Adjusting the main bootstrap file for specific plugin needs is less flexible and potentially error-prone. I think in a monorepo, it makes sense to share the configs but editing them for each other is not ideal.

Plugin name resolution logic in bootstrap file

performance/tests/bootstrap.php

Lines 38 to 67 in 082a106

	$plugin_name = '';
	foreach ( $_SERVER['argv'] as $index => $arg ) {
	if (
	'--testsuite' === $arg &&
	isset( $_SERVER['argv'][ $index + 1 ] ) &&
	'performance-lab' !== $_SERVER['argv'][ $index + 1 ] &&
	file_exists( TESTS_PLUGIN_DIR . '/plugins/' . $_SERVER['argv'][ $index + 1 ] )
	) {
	$plugin_name = $_SERVER['argv'][ $index + 1 ];
	}
	}
	if ( $plugin_name ) {
	$plugin_test_path = TESTS_PLUGIN_DIR . '/plugins/' . $plugin_name;
	tests_add_filter(
	'plugins_loaded',
	static function () use ( $plugin_test_path, $plugin_name ) {
	// Check if plugin has a "plugin/plugin.php" file.
	if ( file_exists( $plugin_test_path . '/' . $plugin_name . '.php' ) ) {
	require_once $plugin_test_path . '/' . $plugin_name . '.php';
	} elseif ( file_exists( $plugin_test_path . '/load.php' ) ) {
	// Check if plugin has a "plugin/load.php" file.
	require_once $plugin_test_path . '/load.php';
	} else {
	echo "Unable to locate standalone plugin bootstrap file in $plugin_test_path.";
	exit( 1 );
	}
	},
	1
	);

• Running tests from within a specific plugin directory becomes non-trivial due to automatic config resolution and can hinder the development/debugging of the individual plugin(s).

• While development using --testsuite requires users to know the specific test suite name within the global phpunit config to run tests for a particular plugin. Now we can include test command as npm/composer script for each plugin but that would also require taking a look at npm/composer scripts to determine for which plugin which test command to run.

• Also adding tests commands as npm/composer script approaches require managing and maintaining separate entries for each plugin. As the number of plugins grows, this leads to an increasingly cumbersome script management experience.

• If you want to work on the plugin from its directory, the current setup has limitations. With the current approach, it will resolve the config automatically.

So, the tradeoff between both is making changes to the main PHPUnit config + updating tests bootstrap file + maintaining it on use cases vs keeping separate PHPUnit config which is just a one-time copy from any other plugin.