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PHP Type Checker Generator

Left: paste a PHPDoc block with @phpstan-type aliases (one or more comments), or plain PHPStan type expressions for convenience. Each alias or plain type becomes a checker. Options under the input control optimization, alias handling, and PHP shape — hover each ? for details. Right: tabs follow Type → Trace → PHP Code; output updates as you edit. Some types cannot be checked at runtime (for example callable signatures) and report a generation error.

Type input

Verbose PHPDoc When on, each checker gets a multi-line PHPDoc with a summary, @param, @return, and @phpstan-assert-if-true. When off (default), only the one-line assert comment is emitted.

Re-Emit input aliases When on, re-emits the @phpstan-type definitions at the top of the generated PHP output.

Optimize When on, rewrites the abstract checkers until stable (inline, simplify, DCE, and related passes) before PHP is rendered. When off, Optimize is skipped.

Inline aliases When on, @phpstan-type cross-references are inlined into each alias body. When off (default), they stay as named references and call the matching entry checker.

Unsafe string array keys Unsound means the generated checker is not guaranteed to match the type: it may accept values that do not match, or reject values that do, producing incorrect results at runtime. When on, array and non-empty-array keys written as string are checked like int|non-decimal-int-string (PHPStan reportUnsafeArrayStringKeyCasting: detect), matching real PHP key casting. When off (default), keys stay string checks — same runtime accept set as PHPStan default/prevent. @phpstan-assert-if-true still uses the input type.

Sealed array shapes When on, array and list shapes without a trailing … reject unknown keys (PHPStan 2.2 bleeding-edge sealed shapes). When off (default), those shapes allow extra keys, matching PHPStan’s default today. @phpstan-assert-if-true still uses the input type.

Emit as Shape of the emitted PHP: top-level functions, or static methods with the chosen visibility.

Generated output

Updating output

Run generate to see output

Run generate to see output

Run generate to see output

Select Source, AST, or Examples for each type on the left. On AST, click +/− to toggle; Alt/⌥-click for a whole subtree.

One group per checker, then Prune. Each group opens with the Initial checker; later steps show Before, After, and Diff.

Warning: Always review generated PHP before using it in production.

Generate PHP 8+ type checking code for PHPDoc types as supported by PHPStan (opens in new tab) with @phpstan-assert-if-true. Source on GitHub (opens in new tab). By @tkw1536 (opens in new tab).