wp-phpstan

Imported from wordpress/agent-skills (skills/wp-phpstan/SKILL.md) via skills.sh. Install upstream with npx skills add wordpress/agent-skills --skill wp-phpstan. Copyright stays with the author.

WP PHPStan

When to use

Use this skill when working on PHPStan in a WordPress codebase, for example:

• setting up or updating phpstan.neon / phpstan.neon.dist
• generating or updating phpstan-baseline.neon
• fixing PHPStan errors via WordPress-friendly PHPDoc (REST requests, hooks, query results)
• handling third-party plugin/theme classes safely (stubs/autoload/targeted ignores)

Inputs required

• wp-project-triage output (run first if you haven't)
• Whether adding/updating Composer dev dependencies is allowed (stubs).
• Whether changing the baseline is allowed for this task.

Procedure

0) Discover PHPStan entrypoints (deterministic)

1. Inspect PHPStan setup (config, baseline, scripts):
   • node skills/wp-phpstan/scripts/phpstan_inspect.mjs

Prefer the repo’s existing composer script (e.g. composer run phpstan) when present.

1) Ensure WordPress core stubs are loaded

szepeviktor/phpstan-wordpress or php-stubs/wordpress-stubs are effectively required for most WordPress plugin/theme repos. Without it, expect a high volume of errors about unknown WordPress core functions.

• Confirm the package is installed (see composer.dependencies in the inspect report).
• Ensure the PHPStan config references the stubs (see references/third-party-classes.md).

2) Ensure a sane phpstan.neon for WordPress projects

• Keep paths focused on first-party code (plugin/theme directories).
• Exclude generated and vendored code (vendor/, node_modules/, build artifacts, tests unless explicitly analyzed).
• Keep ignoreErrors entries narrow and documented.

See:

• references/configuration.md

3) Fix errors with WordPress-specific typing (preferred)

Prefer correcting types over ignoring errors. Common WP patterns that need help:

• REST endpoints: type request parameters using WP_REST_Request<...>
• Hook callbacks: add accurate @param types for callback args
• Database results and iterables: use array shapes or object shapes for query results
• Action Scheduler: type $args array shapes for job callbacks

See:

• references/wordpress-annotations.md

4) Handle third-party plugin/theme classes (only when needed)

When integrating with plugins/themes not present in the analysis environment:

• First, confirm the dependency is real (installed/required).
• Prefer plugin-specific stubs already used in the repo (common examples: php-stubs/woocommerce-stubs, php-stubs/acf-pro-stubs).
• If PHPStan still cannot resolve classes, add targeted ignoreErrors patterns for the specific vendor prefix.

See:

• references/third-party-classes.md

5) Baseline management (use as a migration tool, not a trash bin)

• Generate a baseline once for legacy code, then reduce it over time.
• Do not “baseline” newly introduced errors.

See:

• references/configuration.md

Verification

• Run PHPStan using the discovered command (composer run ... or vendor/bin/phpstan analyse).
• Confirm the baseline file (if used) is included and didn’t grow unexpectedly.
• Re-run after changing ignoreErrors to ensure patterns are not masking unrelated issues.

Failure modes / debugging

• “Class not found”:
  • confirm autoloading/stubs, or add a narrow ignore pattern
• Huge error counts after enabling PHPStan:
  • reduce paths, add excludePaths, start at a lower level, then ratchet up
• Inconsistent types around hooks / REST params:
  • add explicit PHPDoc (see references) rather than runtime guards

Escalation

• If a type depends on a third-party plugin API you can’t confirm, ask for the dependency version or source before inventing types.
• If fixing requires adding new Composer dependencies (stubs/extensions), confirm it with the user first.