Build/Test Tools: Trim the PHPUnit matrix to boundary PHP versions (full matrix runs weekly)

[lancewillett]

What

Trims the PHPUnit test matrix to boundary PHP versions on trunk and pull requests: the highest and lowest supported version of each major. 7.4, 8.0, and 8.5 replace the full seven-minor list, in test-with-mysql, test-with-mariadb, and test-innovation-releases.

Full coverage is preserved by the existing weekly scheduled run: on the Sunday cron, every supported PHP version is tested; push and pull request events test the boundary versions only.

Why

This mirrors the trim #64083 applied to older branches, whose title named "(and possibly trunk)". Version-specific failures cluster at the boundaries of each major, so the intermediate minors add job count without adding coverage. The weekly full run keeps the intermediate versions covered without multiplying job count on every change.

Impact

Base PHPUnit combinations drop from ~168 to ~72 on push and pull requests, roughly a 55% cut, before the unchanged include: jobs. The weekly run is unchanged.

How the weekly full matrix works

The php matrix is conditional on the event:

php: ${{ github.event_name == 'schedule'
        && fromJSON('["7.4","8.0","8.1","8.2","8.3","8.4","8.5"]')
        || fromJSON('["7.4","8.0","8.5"]') }}

Scheduled runs fire from the default branch, so the weekly full sweep covers trunk.

Scope

PHP axis only. Database versions, multisite, memcached, and the single-representative include: jobs are untouched. A database-axis trim on the same principle is a possible follow-up, filed separately.

Trac ticket: Core-65736

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Opus 4.8
Used for: Identifying the boundary-trim approach from the existing older-branch precedent, the weekly-full conditional, and drafting the change and ticket text. Verified manually.

[github-actions]

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Core Committers: Use this line as a base for the props when committing in SVN:

Props lancewillett, johnbillion.

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[Copilot]

Pull request overview

This PR reduces GitHub Actions PHPUnit job counts by trimming the PHP version matrix to boundary versions (lowest/highest supported per major) on the active branch, aiming to preserve meaningful coverage while easing runner load during releases.

Changes:

• Reduce the php matrix in test-with-mysql from seven minors to 7.4, 8.0, and 8.5.
• Reduce the php matrix in test-with-mariadb from seven minors to 7.4, 8.0, and 8.5.
• Reduce the php matrix in test-innovation-releases from seven minors to 7.4, 8.0, and 8.5.

Comments suppressed due to low confidence (1)

.github/workflows/phpunit-tests.yml:157

• The new comment is slightly misleading in this job: while the base php: axis is trimmed to boundary versions, the include: section below still runs additional jobs on intermediate PHP minors (e.g. 8.3). Consider rewording so it’s clear the boundary trim applies to the base matrix only.

        # Test highest and lowest supported version of each major.

---

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[johnbillion]

There is an element of risk with this change, but:

• That can be offset with a new daily or weekly workflow that exercises the full matrix
• The benefit of faster overall feedback as a result of pushes and PRs is worth it, especially shortly prior to and during release when lots of pushes are being made

[lancewillett]

@johnbillion Agree on the tradeoff. If we could make all runs faster, maybe we can keep the full matrix.

Another idea is to allow a PR tag full-ci to kick off the full, ad-hoc.

Apologies, I made a mistake in the first commit. Can you re-review 2538d74 ? Adds the weekly back.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (3)

.github/workflows/phpunit-tests.yml:78

• workflow_dispatch runs will now use the trimmed boundary PHP list because the condition only treats schedule as the full-matrix case. If you want manual runs to retain the ability to exercise the full PHP matrix on demand (without waiting for the weekly cron), include workflow_dispatch in the full-matrix branch and update the comment accordingly.

        # The scheduled run tests every supported PHP version. Other events test the highest and lowest of each major.
        php: ${{ github.event_name == 'schedule' && fromJSON('["7.4","8.0","8.1","8.2","8.3","8.4","8.5"]') || fromJSON('["7.4","8.0","8.5"]') }}

.github/workflows/phpunit-tests.yml:158

• workflow_dispatch runs will now use the trimmed boundary PHP list because the condition only treats schedule as the full-matrix case. If you want manual runs to retain the ability to exercise the full PHP matrix on demand (without waiting for the weekly cron), include workflow_dispatch in the full-matrix branch and update the comment accordingly.

        # The scheduled run tests every supported PHP version. Other events test the highest and lowest of each major.
        php: ${{ github.event_name == 'schedule' && fromJSON('["7.4","8.0","8.1","8.2","8.3","8.4","8.5"]') || fromJSON('["7.4","8.0","8.5"]') }}

.github/workflows/phpunit-tests.yml:213

• workflow_dispatch runs will now use the trimmed boundary PHP list because the condition only treats schedule as the full-matrix case. If you want manual runs to retain the ability to exercise the full PHP matrix on demand (without waiting for the weekly cron), include workflow_dispatch in the full-matrix branch and update the comment accordingly.

        # The scheduled run tests every supported PHP version. Other events test the highest and lowest of each major.
        php: ${{ github.event_name == 'schedule' && fromJSON('["7.4","8.0","8.1","8.2","8.3","8.4","8.5"]') || fromJSON('["7.4","8.0","8.5"]') }}

[github-actions]

A commit was made that fixes the Trac ticket referenced in the description of this pull request.

SVN changeset: 62858
GitHub commit: 5174167

This PR will be closed, but please confirm the accuracy of this and reopen if there is more work to be done.