Run the development build during prepare

[ekamran]

Fixes #350.

Problem

Since core r63983, host reports fail four tests: Tests_Dependencies_jQuery::test_jquery_files_exist for jquery.js, jquery.min.js, jquery-migrate.js and jquery-migrate.min.js.

On the results site, r63982 has 22 passed and 2 failed reports. r63983 has 3 passed and 27 failed, and r64091 is still at 3 and 24. Only core's own reporter passes.

prepare.php runs npm run build, which writes the built files to build/. The test suite runs against src/, which is ABSPATH in the generated wp-tests-config.php. The new test asserts that the jQuery files exist under src/wp-includes/js/jquery/, and only the development build creates that directory.

Fix

Run npm run build:dev instead. It writes the built files into src/, and it is the build that core's own PHPUnit workflow runs: npm ci, then npm run build:dev.

What changes for hosts

• The four jQuery tests pass.
• Tests_Basic::test_build_wp_version_does_not_end_with_src is now skipped, because build/ is no longer produced. Core's own workflow skips it for the same reason.
• Prepare gets a little lighter. There is no build/ directory, which was 152 MB in my run.

Verification

Real end to end runs of prepare.php and test.php against trunk r64092, PHP 8.5, MySQL 9.7.

• master: src/wp-includes/js/jquery/ does not exist after prepare, and the four tests fail with the same messages as in host-tests failing since r63983 (missing/invalid jQuery paths?) #350.
• This branch: the four files exist in src/, and Tests_Dependencies_jQuery passes with 7 tests and 48 assertions.
• Same comparison across the groups most likely to care about built files (dependencies, scripts, blocks, restapi, and the five test files that reference built paths, about 4,800 tests): the only differences are the four fixed tests and the one skipped test above.
• Full suite, 25,703 tests: master ends with 4 failures, the same four tests, and 73 skipped. This branch ends with no failures and 74 skipped. The extra skip is the build version test above.
• php -l, phpcs and git diff --check are clean.

Notes

• This touches the same line as Run npm verbosely when debug mode is enabled #340, which adds the verbosity flags to both npm commands. Whichever lands second needs a one-line rebase, and I will do it.
• Document why NodeJS is needed to run the tests #347 adds README text that names npm run build. It would need the same one-word update.
• The runner's own checks did not catch this because the test step runs with continue-on-error. That is outside this PR.

Use of AI

AI assistance: Yes
Tool(s): Claude Code and Codex
Used for: Investigation, implementation, verification harness, and PR wording. I reviewed the reasoning and test results, and I take responsibility for the contribution.

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Co-authored-by: ekamran <ekamran@git.wordpress.org>
Co-authored-by: kittenkamala <amykamala@git.wordpress.org>
Co-authored-by: chrisdavidmiles <chrisdavidmiles@git.wordpress.org>
Co-authored-by: iarif4u <iarif4u@git.wordpress.org>
Co-authored-by: kmott <mywp459@git.wordpress.org>

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[kittenkamala]

Thank you so much for catching this. Would be great to have some hosts test on their systems to confirm the change to using build:dev is effective.

Maybe @jazzsequence and @chrisdavidmiles could test on Pantheon and BlueHost systems

[iarif4u]

Tested on an xCloud server, as a host test of the build:dev change.

Environment

• Ubuntu 24.04.5, provisioned by xCloud (nginx + MySQL stack). 2 vCPU, 1.8 GB RAM, with 4 GB swap (the 1 GB xCloud swapfile plus 3 GB that I added as headroom for the build).
• PHP 8.4.26 (ondrej PPA), MySQL 8.0.46, Node.js 24.21.0 / npm 11.19.0 from NodeSource setup_24.x, Composer 2.10.3.
• Runner master (d974e38) and this branch (d32c0f2), both set up by a non-root user. Both checkouts were the same WordPress trunk, r64225 (702a0d0).
• Outbound HTTPS to ghcr.io and pkg-containers.githubusercontent.com works. The Gutenberg download needs both.

Results (prepare.php, then --filter "Tests_Dependencies_jQuery|test_build_wp_version_does_not_end_with_src")

	master	this PR
prepare.php	OK, 77 s	OK, 70 s
src/wp-includes/js/jquery/	missing	jquery.js, jquery.min.js, jquery-migrate.js, jquery-migrate.min.js
build/	created, 159 MB	not created
Tests	8 tests, 4 failures (the four in #350)	8 tests, 48 assertions, 0 failures, 1 skipped (test_build_wp_version_does_not_end_with_src)

So the change fixes #350 on this stack too, with the same counts as in the PR description.

Full suite (25,936 tests, same server, same r64225, about 460 s each)

	master	this PR
Failures + errors	11	7
Skipped	30	31

• Only on master: the four Tests_Dependencies_jQuery failures from host-tests failing since r63983 (missing/invalid jQuery paths?) #350.
• Only on this PR: no new failures. The one extra skip is Tests_Basic::test_build_wp_version_does_not_end_with_src, as expected.
• On both: the same 7 timezone tests (for example Tests_Date_wpTimezone::test_should_return_deprecated_timezone_string, and DateInvalidTimeZoneException for America/Buenos_Aires and Canada/Newfoundland). This comes from the server, not the runner: this PHP uses the system time zone database ("Olson" Timezone Database Version => 0.system), and Ubuntu 24.04 moves the deprecated zone names into the tzdata-legacy package, which was not installed. After apt install tzdata-legacy, those test classes pass (178 tests, 0 failures).

One follow-up: when this lands, I will update #347, which still names npm run build. Its "Extra work" note about build:dev will also no longer apply.

[ekamran]

Thanks for the thorough run, Arif. Same numbers as my local runs, and xCloud is a different stack from mine, so that is the host confirmation Amy asked for.

The tzdata-legacy note is useful on its own: the 7 timezone failures are a server package gap, not the runner, and apt install tzdata-legacy clears them.

Sounds good on #347, the build:dev wording there can follow once this lands.

[chrisdavidmiles]

I confirmed this on a Bluehost server. I ran the same wordpress-develop checkout (c64de70) both ways: on master, src/wp-includes/js/jquery/ is absent and the four test_jquery_files_exist cases fail; on this branch, the four files build into src/ and pass, with test_build_wp_version_does_not_end_with_src skipped as expected. These results match the xCloud run.