php-version-detector

Detect the minimum PHP version a piece of code needs to run. It walks the code's AST and flags the language features, functions, classes and constants that were introduced in a given version (5.3 → 8.4).

Requirements

• PHP 7.4+ (tested on 8.1 – 8.4)
• One AST backend:
  • preferred: the native ast extension (fast), or
  • fallback: nikic/php-parser — pure PHP, installed via Composer.

The ast extension is optional. When it is not loaded the tool automatically falls back to nikic/php-parser, so composer install alone is enough to run it.

Install

composer install

Usage

# a single file
./php-version-detector path/to/file.php

# or a whole directory (recursively scans *.php)
./php-version-detector path/to/project/

Example output:

----------------------------------------------------------------------------------------------------
v   | type    | confirmed | evidence                      | file                          | line
----------------------------------------------------------------------------------------------------
81  | Feature | Confident | Enums                         | app/Suit.php                  | 3
----------------------------------------------------------------------------------------------------
80  | Function | Confident | str_contains                 | app/Str.php                   | 12
----------------------------------------------------------------------------------------------------

Docker

The image bundles the fast ast extension and the Composer dependencies:

docker build -t php-version-detector .
docker run -t --rm -v $(pwd):/app php-version-detector /app/tests/ast-feed.php

Tests

composer test

CI runs the suite on PHP 8.1 – 8.4 against both the ast extension and the pure-PHP nikic/php-parser fallback (see .github/workflows/ci.yml).

How it works

ast\parse_code() (or the php-parser adapter) produces an AST; a set of per-version detectors (detect/php*.php) walk every node looking for:

• Features — language constructs (match, enums, arrow functions, …)
• Functions — calls to functions added in a version
• Classes — new/extends of classes added in a version
• Constants — references to constants added in a version

Findings are Confident unless guarded by a function_exists() / class_exists() check, in which case they are downgraded to Possible.

Resources

• https://blog.madewithlove.be/post/thread-carefully/