feat: print PHP 8.4 property hooks (and abstract/final/private(set) properties)

[mreiden]

Problem

php-parser 3.7 (glayzzle/php-parser#1142) parses PHP 8.4 property hooks into property.hooks, but printer.mjs never prints them. Formatting

public ?int $agencyId {
    get => $this->agency?->id;
    set(?int $id) { /* ... */ }
}

exits 0 and writes back public ?int $agencyId; — the hooks are silently deleted. A comment anywhere inside the hooks turns that into Error: Comment "..." was not printed instead, which is the only thing that stopped us from losing code.

The same class of bug affects property modifiers the parser already exposes on propertystatement: abstract, final and the asymmetric set visibility (public private(set) static string $webUrl;) were all dropped on format.

Fix

• New printPropertyHooks() used by property and by parameter (hooks on promoted constructor properties), and a propertyhook case printing [#[attr] ][final ][&]get|set[(param)] followed by ;, => expr; (via printAssignmentRight, so long expressions break like assignments) or { ... }.
• Layout follows PER-CS 4.9: brace on the property line, one hook per line (a single blank line between hooks is preserved), and body-less declarations on one line: public string $name { get; set; }.
• lineShouldEndWithSemicolon(): a hooked property statement ends with }, not }; (a parse error inside a class body).
• propertystatement prints abstract, final and visibilitySet (public private(set)).
• handleFunctionParameter() guards against a missing preceding node, reachable with a comment right after set(.

No parser change is needed: php-parser@^3.7.0 is already the dependency. Supersedes #2458, which needed a fork of the parser at the time; this builds on the same idea and additionally covers hook attributes, promoted-parameter hooks, the one-line form and the property modifiers.

Tests

tests/property-hooks/ covers interface and abstract declarations, => and block bodies, final, &get, set(Type $v), attributes on hooks, comments between/after hooks, empty bodies, promoted constructor parameters, long expressions, and the property modifiers. Verified with AST_COMPARE=1; output re-formats idempotently and passes php -l.

🤖 Generated with Claude Code

[elnebuloso]

Thanks for this, @mreiden!

I tested this branch on top of main (269374b) against PHP 8.5.11. Hooks are printed correctly in every case I tried,
and each output passes php -l and keeps the input's tokens:

• get arrow + set block: public string $name { get => ...; set(string $v) { ... } }
• interface property: interface I { public string $name { get; } } (on main this becomes invalid PHP)
• hook on a promoted constructor property: __construct(public string $y { get => strtoupper($this->y); })
• private(set) / protected(set) on properties, including static

One case still loses code: asymmetric visibility on a promoted constructor parameter.

class C { public function __construct(public private(set) int $x) {} }

becomes

public function __construct(public int $x) {}

php-parser 3.7.0 has the set visibility in parameter.flagsSet (private = 4 here), but the parameter case only
prints flags. Would it fit into this PR?

[mreiden]

Thanks for testing it so thoroughly, @elnebuloso — good catch. Fixed in 313e41e: the parameter case now prints flagsSet alongside flags, so public private(set) int $x keeps its private(set). I added your case to the tests/property-hooks fixture along with private(set) on its own (printed as written, without inventing a public), protected(set) readonly, and a promoted parameter that has both private(set) and a hook.