Run Multisite tests in parallel during CI

[johnbillion]

Related: #50401

The PHPUnit test workflow takes around 26 minutes (±2 minutes) to run on GitHub Actions. Each job within each run runs the whole test suite, with a total of 8 jobs (7 distinct PHP versions plus an extra job for 7.4 with memcached).

We should take more advantage of GitHub Actions' parallel processing of jobs within a workflow. If we reduce the times for each job by spreading their work across multiple jobs and all jobs still run in parallel, we reduce the overall workflow time as long as the time saving is greater than the time taken to set up each job (download the artefact, install dependencies, and start the containers).

One way to do this is by splitting the Multisite tests into their own jobs and adding a multisite flag to the matrix. This very roughly halves the time for the actual PHPUnit tests in each job, and in practice reduces the total duration of the workflow from ~26 minutes to ~16 minutes.

Items to consider before this can be implemented:

• How to correctly report the results to the WordPress.org host test results collector

https://core.trac.wordpress.org/ticket/52548

Also, it's probably also worthwhile to copy this idea over to the test coverage workflow as well.

Opened https://core.trac.wordpress.org/ticket/52561 for the coverage report.

Just one remaining item for this change then - will the hosting test result reporter handle two submissions (one for single site and one for Multisite) ok? Should this be a separate ticket to prevent it from blocking this change?

For now I set multisite to false for the report job. I'll open a separate ticket for that too.

I think this is ready to go. Anything else from you @desrosj ?

[johnbillion]

In 50379:

Build/Test Tools: Split the single site and Multisite PHPUnit test runs on CI into separate jobs so they run in parallel.

This reduces the total duration of the test suite from ~26 minutes to ~16 minutes. Hurrah!

Fixes #52548

https://core.trac.wordpress.org/changeset/50379

[desrosj]

In 50602:

Build/Test Tools: Backport GitHub Action and build improvements to the 5.6 branch.

This backports several build and test tool improvements to the 5.6 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• The ability to run PHPUnit tests from src instead of build [50441-50443].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50267,50299,50379,50387,50413,50416,50432,50435-50436,50441-50444,50446,50473-50474,50476,50479,50485-50487,50545,50579,50590,50592,50598] to the 5.6 branch.
See #50401, #51734, #51801, #51802, #52548, #52608, #52612, #52623, #52624, #52625, #52645, #52653, #52658, #52660, #52667, #52786.

[desrosj]

In 50603:

Build/Test Tools: Backport GitHub Action and build improvements to the 5.5 branch.

This backports several build and test tool improvements to the 5.5 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• The ability to run PHPUnit tests from src instead of build [50441-50443].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50267,50299,50379,50387,50413,50416,50432,50435-50436,50441-50444,50446,50473-50474,50476,50479,50485-50487,50545,50579,50590,50592,50598] to the 5.5 branch.
See #50401, #51734, #51801, #51802, #52548, #52608, #52612, #52623, #52624, #52625, #52645, #52653, #52658, #52660, #52667, #52786.

[desrosj]

In 50604:

Build/Test Tools: Backport GitHub Action and build improvements to the 5.4 branch.

This backports several build and test tool improvements to the 5.4 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• The ability to run PHPUnit tests from src instead of build [50441-50443].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50267,50299,50379,50387,50413,50416,50432,50435-50436,50441-50444,50446,50473-50474,50476,50479,50485-50487,50545,50579,50590,50598] to the 5.4 branch.
See #50401, #51734, #51801, #51802, #52548, #52608, #52612, #52623, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50605:

Build/Test Tools: Backport GitHub Action and build improvements to the 5.3 branch.

This backports several build and test tool improvements to the 5.3 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• The ability to run PHPUnit tests from src instead of build [50441-50443].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50267,50299,50379,50387,50413,50416,50432,50435-50436,50441-50444,50446,50473-50474,50476,50479,50485-50487,50545,50579,50590,50598] to the 5.3 branch.
See #50401, #51734, #51801, #51802, #52548, #52608, #52612, #52623, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50606:

Build/Test Tools: Backport GitHub Action and build improvements to the 5.2 branch.

This backports several build and test tool improvements to the 5.2 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• The ability to run PHPUnit tests from src instead of build [50441-50443].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50267,50299,50379,50387,50413,50416,50432,50435-50436,50441-50444,50446,50473-50474,50476,50479,50485-50487,50545,50579,50590,50598] to the 5.2 branch.
See #50401, #51734, #51801, #51802, #52548, #52608, #52612, #52623, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50622:

Build/Test Tools: Backport GitHub Action and build improvements to the 5.1 branch.

This backports several build and test tool improvements to the 5.1 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [45317,50267,50379,50387,50413,50416,50432,50435-50436,50444,50446,50473-50474,50476,50479,50485-50487,50545,50579,50590,50598] to the 5.1 branch.
See #50401, #51801, #51802, #52548, #52608, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50624:

Build/Test Tools: Backport GitHub Action and build improvements to the 5.0 branch.

This backports several build and test tool improvements to the 5.0 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [45317,50267,50379,50387,50413,50416,50432,50435-50436,50444,50446,50473-50474,50476,50479,50485-50487,50545,50579,50590,50598] to the 5.0 branch.
See #50401, #51801, #51802, #52548, #52608, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50625:

Build/Test Tools: Backport GitHub Action and build improvements to the 4.9 branch.

This backports several build and test tool improvements to the 4.9 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50413,50416,50432,50435,50436,50444,50446,50473,50474,50476,50479,50485,50486,50487,50545,50579,50590] to the 4.9 branch.
See #50401, #51801, #51802, #52548, #52608, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50626:

Build/Test Tools: Backport GitHub Action and build improvements to the 3.7 branch.

This backports several build and test tool improvements to the 3.7 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50413,50416,50432,50435,50436,50444,50446,50473,50474,50476,50479,50485,50486,50487,50545,50579,50590] to the 3.7 branch.
See #50401, #51801, #51802, #52548, #52608, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50635:

Build/Test Tools: Backport GitHub Action and build improvements to the 4.8 branch.

This backports several build and test tool improvements to the 4.8 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50413,50416,50432,50435,50436,50444,50446,50473,50474,50476,50479,50485,50486,50487,50545,50579,50590] to the 4.8 branch.
See #50401, #51801, #51802, #52548, #52608, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50636:

Build/Test Tools: Backport GitHub Action and build improvements to the 4.7 branch.

This backports several build and test tool improvements to the 4.7 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50413,50416,50432,50435,50436,50444,50446,50473,50474,50476,50479,50485,50486,50487,50545,50579,50590] to the 4.7 branch.
See #50401, #51801, #51802, #52548, #52608, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50637:

Build/Test Tools: Backport GitHub Action and build improvements to the 4.6 branch.

This backports several build and test tool improvements to the 4.6 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50416,50432,50435,50436,50444,50446,50473,50474,50476,50479,50485,50486,50487,50545,50579,50590] to the 4.6 branch.
See #50401, #51801, #51802, #52548, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50638:

Build/Test Tools: Backport GitHub Action and build improvements to the 4.5 branch.

This backports several build and test tool improvements to the 4.5 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50416,50432,50435,50436,50444,50446,50473,50474,50476,50479,50485,50486,50487,50545,50579,50590] to the 4.5 branch.
See #50401, #51801, #51802, #52548, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50639:

Build/Test Tools: Backport GitHub Action and build improvements to the 4.4 branch.

This backports several build and test tool improvements to the 4.4 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50416,50432,50435,50436,50444,50446,50473,50474,50476,50479,50485,50486,50487,50545,50579,50590] to the 4.4 branch.
See #50401, #51801, #51802, #52548, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50640:

Build/Test Tools: Backport GitHub Action and build improvements to the 4.3 branch.

This backports several build and test tool improvements to the 4.3 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50416,50432,50435,50436,50444,50446,50473,50474,50476,50479,50485,50486,50487,50545,50579,50590] to the 4.3 branch.
See #50401, #51801, #51802, #52548, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50642:

Build/Test Tools: Backport GitHub Action and build improvements to the 4.2 branch.

This backports several build and test tool improvements to the 4.2 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50416,50432,50435,50436,50444,50446,50473,50474,50476,50479,50485,50486,50487,50545,50579,50590] to the 4.2 branch.
See #50401, #51801, #51802, #52548, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50643:

Build/Test Tools: Backport GitHub Action and build improvements to the 4.1 branch.

This backports several build and test tool improvements to the 4.1 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50416,50432,50435-50436,50444,50446,50473-50474,50476,50479,50485-50487,50545,50590] to the 4.1 branch.
See #50401, #51801, #51802, #52548, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50644:

Build/Test Tools: Backport GitHub Action and build improvements to the 4.0 branch.

This backports several build and test tool improvements to the 4.0 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50416,50432,50435-50436,50444,50446,50473-50474,50476,50479,50485-50487,50545,50590] to the 4.0 branch.
See #50401, #51801, #51802, #52548, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50645:

Build/Test Tools: Backport GitHub Action and build improvements to the 3.9 branch.

This backports several build and test tool improvements to the 3.9 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50416,50432,50435-50436,50444,50446,50473-50474,50476,50479,50485-50487,50545,50590] to the 3.9 branch.
See #50401, #51801, #51802, #52548, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.

[desrosj]

In 50646:

Build/Test Tools: Backport GitHub Action and build improvements to the 3.8 branch.

This backports several build and test tool improvements to the 3.8 branch. Most notably, this includes:

• The changes required to allow each workflow to be triggered by the workflow_dispatch event so that tests can be run on a schedule [50590].
• Splitting single site and multisite tests into parallel jobs [50379].
• Split slow tests into separate, parallel jobs for PHP <= 5.6 [50444].
• Better branch and path scoping for GitHub Action workflows when running on pull_request [50432,50479].
• Several devDependency updates.

Merges [50379,50387,50416,50432,50435-50436,50444,50446,50473-50474,50476,50479,50485-50487,50545,50590] to the 3.8 branch.
See #50401, #51801, #51802, #52548, #52612, #52624, #52625, #52645, #52653, #52658, #52660, #52667.