Build/Test Tools: Update PHPStan to 2.3.0 and replace the deprecated result cache meta extension

[westonruter]

✅ Committed in r64237 (ec8bf88).

---

Updates PHPStan to 2.3.0 (blog post) and phpstan/phpstan-phpunit to 2.1.1, which requires PHPStan 2.3. It then moves the bundled hook documentation tooling off the API that 2.3.0 deprecates.

Upgrade

• Baselines are regenerated. 12 variable.undefined entries no longer match, because the rewritten engine now sees those variables are always defined.
• WP_HTML_Processor::run_adoption_agency_algorithm() gains a greater.alwaysTrue and a greaterOrEqual.alwaysFalse baseline entry. Every path through its outer loop body either returns or calls bail(), which never returns, so the loop never runs a second time and its counters never change. PHPStan 2.3 now builds a loop's back edge only from reachable continue statements (Build a loop's back edge from its continue statements when the body end is unreachable phpstan/phpstan-src#6420), so it reports both comparisons as constant. The loop is scaffolding for parts of the algorithm that are not yet supported, so the errors are baselined as work still to do, not added to the permanent ignore list.

Replace the deprecated ResultCacheMetaExtension

2.3.0 deprecates ResultCacheMetaExtension in favor of dependencies declared on the scope. A changed meta hash discards the whole result cache, while a declared dependency re-analyzes only the files that declared it. HookDocsResultCacheMetaExtension folded two hashes into the cache key, and both are now handled another way:

• Inherited hook docblocks. Resolving a "This filter is documented in <file>" reference now calls trackFileDependency() on each candidate path it tests. Editing a canonical docblock therefore re-analyzes only the files that reference it. Candidates that do not exist are tracked too, because creating one would change which file the reference names. This also removes a scan of wp-admin, wp-includes and the bundled themes that ran on every analysis.
• The extension sources themselves. PHPStan 2.3 already runs a full analysis when the source of any registered extension or bootstrap file changes (-vv reports "Result cache not used because extension file … hash does not match"), so this hash was redundant.

The extension, its base.neon registration and the hashing helpers in HookDocBlock are removed. The rules and the apply_filters() return type extension now document their scope as Scope&DependencyTracker, which is what PHPStan passes them.

To test the tracking, a @param was added to the canonical the_title docblock in wp-includes/post-template.php with a warm cache. 22 files were re-analyzed, and every call site that inherits that docblock reported the parameter-count mismatch.

Checked, no change needed

• The currentPhpVersionSimpleParser override in base.neon, which the README says to check after an upgrade, still connects to 2.3.0's parser setup, since cachedSimpleParser wraps it.
• The two reportUnmatched: false entries in phpstan.neon.dist (substr_compare() and ValueError in @throws) still match.
• Unused-variable detection and inference for closures and static variables are bleeding edge only, which the dist configuration does not include.

Trac ticket: https://core.trac.wordpress.org/ticket/65817

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Opus 5.5
Used for: Performing the upgrade, reviewing the release notes and the new result cache APIs, implementing the dependency tracking, verifying it, and drafting this description.

---

This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

🤖 Generated with Claude Code

[github-actions]

Test using WordPress Playground

The changes in this pull request can previewed and tested using a WordPress Playground instance.

WordPress Playground is an experimental project that creates a full WordPress instance entirely within the browser.

Some things to be aware of

• All changes will be lost when closing a tab with a Playground instance.
• All changes will be lost when refreshing the page.
• A fresh instance is created each time the link below is clicked.
• Every time this pull request is updated, a new ZIP file containing all changes is created. If changes are not reflected in the Playground instance,
  it's possible that the most recent build failed, or has not completed. Check the list of workflow runs to be sure.

For more details about these limitations and more, check out the Limitations page in the WordPress Playground documentation.

Test this pull request with WordPress Playground.

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

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

Props westonruter.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.