Revert phpcs testVersion back to PHP 5.6

[hellofromtonya]

Part of #52344

What?

Reverts the PHP version back to 5.6 for WPCS CI job.

I've changed my mind and now believe WPCS should continue checking PHP compatibility at 5.6.

See:

• PR Drops PHP 5.6 CI jobs that run on WordPress trunk #52345
• Commit d9022ff.

Why?

Gutenberg needs to continue supporting PHP 5.6. Reverting the WPCS CI, i.e. the Unit Tests / PHP coding standards (pull_request) job, is part of the tooling that helps check PHP compatibility for all code changes.

Why does Gutenberg need to supporting PHP 5.6? Because it supports the latest 2 WordPress major versions, which as of today is WP 6.1 and 6.2. Both of these WP versions support PHP 5.6. Thus, so must Gutenberg.

For example, let's say a contributor declares a function return type. Function return type declarations are valid in PHP 7.0, but not compatible with PHP 5.6.

How?

This PR reverts the phpcs testValue change back to 5.6-.

Testing Instructions

The CI Unit Tests / PHP coding standards (pull_request) job in this PR should pass ✅

Testing it locally involves several steps. The following sections provide set up and testing instructions.

Step 1: Set up

Sample code change

Change a function to declare a return type. For example, change wp_fonts() to

function wp_fonts(): WP_Fonts {

Run PHPCS

You'll use the following command to run phpcs in your favorite command line tool:

composer run lint -- ./lib/experimental/fonts-api/fonts-api.php

Run Gutenberg on PHP 5.6

With wp-env running on Docker, you can add a .wp-env.override.json file locally and define the phpVersion as `"5.6".

Step 2: Before applying the change in this PR:

1. Run the lint above. Notice WPCS passes.

> phpcs --standard=phpcs.xml.dist './lib/experimental/fonts-api/fonts-api.php'
. 1 / 1 (100%)

Time: 123ms; Memory: 14MB

2. Now run Gutenberg on PHP 5.6. A fatal error should happen.

Parse error: syntax error, unexpected ':', expecting '{' in /var/www/html/wp-content/plugins/gutenberg/lib/experimental/fonts-api/fonts-api.php on line 20

Step 3: Apply this PR's change and then:

1. Run the lint above. WPCS should now fail.

> phpcs --standard=phpcs.xml.dist './lib/experimental/fonts-api/fonts-api.php'
E 1 / 1 (100%)

FILE: /Volumes/DevSSD/Dev/wordpress-develop/src/wp-content/plugins/gutenberg/lib/experimental/fonts-api/fonts-api.php
-----------------------------------------------------------------------------------------------------------------------------------------------------------
FOUND 1 ERROR AFFECTING 1 LINE
-----------------------------------------------------------------------------------------------------------------------------------------------------------
 20 | ERROR | Class name return type is not present in PHP version 5.6 or earlier
    |       | (PHPCompatibility.FunctionDeclarations.NewReturnTypeDeclarations.class_nameFound)
-----------------------------------------------------------------------------------------------------------------------------------------------------------

Time: 125ms; Memory: 16MB

2. Run Gutenberg on PHP 5.6. No fatal error should happen.

[github-actions]

Flaky tests detected in 830b86e.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/5477528738
📝 Reported issues:

• [Flaky Test] shouldn't conflict with server-side autosave #35176 in specs/editor/various/autosave.test.js

[anton-vlasenko]

This PR reverts one of the changes that were introduced in #52345, so I consider it to be safe.
Reverting coding standards checks back to PHP 5.6 makes sense to me (please see the reasoning in the PR's description); therefore, I approve this PR.

[anton-vlasenko]

I believe this PR should also be backported to the wp/6.3 branch (once it's merged into trunk), along with the original pull request: #52345 (comment)

[hellofromtonya]

Thank you @anton-vlasenko. I switched the label to backport this change to the Gutenberg RC branch, vs going into WP Core.

[hellofromtonya]

Whoopsie, I see after reading @Mamaduka's comment on the other PR. Looks like this is needed on both the RC release/16.2 and wp/6.3 branches.

[Mamaduka]

If the original PR hasn’t been backported yet then there’s no need to backport revert commit.

[hellofromtonya]

If the original PR hasn’t been backported yet then there’s no need to backport revert commit.

This commit is a partial revert of the original PR. The original PR also includes removing the 2 PHP 5.6 unit test on WordPress trunk CI job. Therefore, both need to be backported.

[tellthemachines]

I just cherry-picked this PR to the update/first-pre-beta-4 branch to get it included in the next release: 9dc955e

[ockham]

@fullofcaffeine cherry-picked this to the release/16.2 branch in e110b21.