add-wp-function

name	add-wp-function
description	Add a WordPress function replacement. Full workflow from WP source to Rust implementation, testing, and registration.
disable-model-invocation	true
argument-hint	[function_name]

Add: $ARGUMENTS

1. Study WordPress source

Start the profiling stack, find and read the source:

cd profiling && docker compose up -d
docker compose exec php-fpm php -d memory_limit=512M -r "
require '/var/www/html/wp-load.php';
\$ref = new ReflectionFunction('$ARGUMENTS');
echo \$ref->getFileName() . ':' . \$ref->getStartLine() . '-' . \$ref->getEndLine();
"

Document: operations in order, whether it calls apply_filters (and filter name), whether pluggable, dependencies, edge cases.

2. Generate fixtures

Create php/fixture-generator/functions/$ARGUMENTS.php following the pattern of existing definitions. Generate: docker compose -f profiling/docker-compose.yml exec php-fpm php -d memory_limit=512M /app/php/fixture-generator/generate.php --function=$ARGUMENTS --output=/app/fixtures/

3. Implement in patina-core

Add to the appropriate module (escaping/, kses/, formatting/, sanitize/, pluggable/). Follow the patterns in existing implementations. Include a matches_wordpress_fixtures test.

4. Register in patina-ext

Add #[php_function] + wrap_function!() in lib.rs. Follow existing function patterns:

• Raw patina_* version (always)
• _filtered version with apply_filters callback (if WP function uses filters)
• Add filtered variant to OVERRIDES if non-pluggable

5. Add tests, fuzz target, benchmarks

• PHP test in php/tests/ extending FixtureTestCase
• Fuzz target in fuzz/fuzz_targets/ + [[bin]] in fuzz/Cargo.toml
• Criterion bench + PHP benchmark with reference implementation

6. Verify

make check
cargo +nightly fuzz run fuzz_$ARGUMENTS -- -max_total_time=30