Composer: allow composer/installers 2.x

[jrfnl]

What?

Composer released the first version of composer/installers 2.x over three years ago.

The 2.x range has a minimum PHP version of PHP 7.2. While WordPress and Gutenberg still supported PHP < 7.2, the requirement could have been set to ^1.0 || ^2.0, but as support for PHP < 7.2 has now been dropped, I see no reason not to require the package at ^2.0 outright.

Having said that, there may still be other plugins out there which don't allow for the composer/installers 2.x package yet and if one such plugins would be installed as a dependency alongside Gutenberg, this would lead to an unresolvable conflict when running composer install for such a project.

So with that in mind, I'm erring on the side of caution and propose to change the requirements to ^1.0 || ^2.0.

Note: this will also get rid of a PHP 8.4 deprecation notice when running various Composer commands.

Refs:

• https://github.com/composer/installers/blob/main/CHANGELOG.md
• https://github.com/composer/installers/releases

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[desrosj]

Thanks @jrfnl. This makes sense to me.

I was trying to think of a way to eventually remove 1.x. Maybe we could:

• Call this out in the release notes when the next version of the plugin is released.
• Drop 1.x support along with the next PHP version update, whenever that ends up being.

[jrfnl]

I was trying to think of a way to eventually remove 1.x. Maybe we could:

• Call this out in the release notes when the next version of the plugin is released.

That's always a good thing.

• Drop 1.x support along with the next PHP version update, whenever that ends up being.

I would be hesitant/reluctant to do so as, for the following reasons:

• Having it set at ^1.0 || ^2.0 doesn't do any harm. Composer will just install whichever version will work for all dependencies of the "client project".
• There is no maintenance overhead involved, so there is no reason or urgency to drop support for v 1.x.
  AFAICS this plugin doesn't have any custom code for the integration, so it relies completely on the installer, which is not maintained here.
• Depending on the skill level of the person running composer install, it may be an insurmountable problem, as a conflict like this cannot easily be solved in the "client project" itself, but would need PRs upstream (and for those to be accepted). (well, it can be with some hacks, but that's not for everyone and, again, hacks require a certain skill level).

I think a better measurement of when support for v 1.x can be dropped, would be to get in touch with WP Packagist and see if they can generate stats about:

• How many of the plugins hosted there declare a non-dev dependency on composer-installers.
• How popular those plugins are.
• What the breakdown is of the required versions for the composer-installers dependency in those plugins.

Only when there are barely any plugins left which have their requirement set to ^1.0 (without || ^2.0) will it be safe to drop support for 1.x.

[desrosj]

This seems like a reasonable and safe approach. We can explore potentially dropping 1.x separately in the future.