Classmap autoload for backed enum not working in all cases

[marc-mabe]

I have defined an enum in my code as follows:

<?php

declare(strict_types=1);

namespace App\Value;

enum ReportExecutionStatus:string
{
    // cases
}

But composer fails to extract the class name and extracts ReportExecutionStatus:string instead of ReportExecutionStatus.
If I change the enum definition to enum ReportExecutionStatus: string it works as expected.

My composer.json:

{
    "type": "project",
    "license": "proprietary",
    "minimum-stability": "stable",
    "prefer-stable": true,
    "require": {
        "php": ">=8.1",
        "ext-ctype": "*",
        "ext-iconv": "*",
        "ext-intl": "*",
        "ext-mbstring": "*",
        "ext-pdo": "*",
        "aws/aws-sdk-php": "^3.209.14",
        "doctrine/annotations": "^1.13.2",
        "doctrine/doctrine-bundle": "^2.5.5",
        "doctrine/orm": "^2.11.0",
        "phpdocumentor/reflection-docblock": "^5.3.0",
        "sensio/framework-extra-bundle": "^6.2.6",
        "symfony/asset": "6.0.*",
        "symfony/console": "6.0.*",
        "symfony/dotenv": "6.0.*",
        "symfony/expression-language": "6.0.*",
        "symfony/flex": "^2.1.4",
        "symfony/form": "6.0.*",
        "symfony/framework-bundle": "6.0.*",
        "symfony/http-client": "6.0.*",
        "symfony/intl": "6.0.*",
        "symfony/mailer": "6.0.*",
        "symfony/messenger": "6.0.*",
        "symfony/mime": "6.0.*",
        "symfony/monolog-bundle": "^3.7.1",
        "symfony/notifier": "6.0.*",
        "symfony/process": "6.0.*",
        "symfony/property-access": "6.0.*",
        "symfony/property-info": "6.0.*",
        "symfony/proxy-manager-bridge": "6.0.*",
        "symfony/runtime": "6.0.*",
        "symfony/security-bundle": "6.0.*",
        "symfony/serializer": "6.0.*",
        "symfony/string": "6.0.*",
        "symfony/translation": "6.0.*",
        "symfony/twig-bundle": "6.0.*",
        "symfony/validator": "6.0.*",
        "symfony/web-link": "6.0.*",
        "symfony/webpack-encore-bundle": "^1.13.2",
        "symfony/yaml": "6.0.*",
        "twig/extra-bundle": "^3.3.7",
        "twig/twig": "^3.3.7"
    },
    "require-dev": {
        "friendsofphp/php-cs-fixer": "^3.4.0",
        "jetbrains/phpstorm-attributes": "^1.0",
        "phpstan/phpstan": "^1.4.2",
        "phpstan/phpstan-doctrine": "^1.2.7",
        "phpunit/phpunit": "^9.5.13",
        "symfony/browser-kit": "6.0.*",
        "symfony/css-selector": "6.0.*",
        "symfony/debug-bundle": "6.0.*",
        "symfony/maker-bundle": "^1.36.4",
        "symfony/phpunit-bridge": "^6.0",
        "symfony/stopwatch": "6.0.*",
        "symfony/web-profiler-bundle": "6.0.*"
    },
    "config": {
        "optimize-autoloader": true,
        "preferred-install": {
            "*": "dist"
        },
        "sort-packages": true,
        "allow-plugins": {
            "composer/package-versions-deprecated": true,
            "symfony/flex": true,
            "symfony/runtime": true
        }
    },
    "autoload": {
        "psr-4": {
            "App\\": "src/"
        }
    },
    "autoload-dev": {
        "psr-4": {
            "App\\Tests\\": "tests/"
        }
    },
    "replace": {
        "symfony/polyfill-ctype": "*",
        "symfony/polyfill-iconv": "*",
        "symfony/polyfill-intl-grapheme": "*",
        "symfony/polyfill-intl-icu": "*",
        "symfony/polyfill-intl-idn": "*",
        "symfony/polyfill-intl-messageformatter": "*",
        "symfony/polyfill-intl-normalizer": "*",
        "symfony/polyfill-mbstring": "*",
        "symfony/polyfill-php72": "*",
        "symfony/polyfill-php73": "*",
        "symfony/polyfill-php74": "*",
        "symfony/polyfill-php80": "*",
        "symfony/polyfill-php81": "*"
    },
    "scripts": {
        "auto-scripts": {
            "cache:clear": "symfony-cmd",
            "assets:install %PUBLIC_DIR%": "symfony-cmd"
        },
        "post-install-cmd": [
            "@auto-scripts"
        ],
        "post-update-cmd": [
            "@auto-scripts"
        ]
    },
    "conflict": {
        "symfony/symfony": "*"
    },
    "extra": {
        "symfony": {
            "allow-contrib": false,
            "require": "6.0.*"
        }
    }
}

Output of composer diagnose:

$ composer diagnose
Checking composer.json: OK
Checking platform settings: OK
Checking git settings: OK
Checking http connectivity to packagist: OK
Checking https connectivity to packagist: OK
Checking github.com rate limit: OK
Checking disk free space: OK
Checking pubkeys: FAIL
Missing pubkey for tags verification
Missing pubkey for dev verification
Run composer self-update --update-keys to set them up
Checking composer version: OK
Composer version: 2.2.5
PHP version: 8.1.2
PHP binary path: /usr/local/bin/php
OpenSSL version: OpenSSL 1.1.1l  24 Aug 2021
cURL version: 7.80.0 libz 1.2.11 ssl OpenSSL/1.1.1l
zip: extension present, unzip present, 7-Zip not available

When I run this command: composer -vvv dumpautoload I get the following output:

$ composer -vvv dumpautoload
Running 2.2.5 (2022-01-21 17:25:52) with PHP 8.1.2 on Linux / 5.11.0-34-generic
Reading ./composer.json (/app/composer.json)
Loading config file ./composer.json (/app/composer.json)
Checked CA file /etc/pki/tls/certs/ca-bundle.crt does not exist or it is not a file.
Checked directory /etc/pki/tls/certs/ca-bundle.crt does not exist or it is not a directory.
Checked CA file /etc/ssl/certs/ca-certificates.crt: valid
Executing command (/app): git branch -a --no-color --no-abbrev -v
Executing command (/app): git describe --exact-match --tags
Executing command (CWD): git --version
Executing command (/app): git log --pretty="%H" -n1 HEAD
Executing command (/app): hg branch
Executing command (/app): fossil branch list
Executing command (/app): fossil tag list
Executing command (/app): svn info --xml
Failed to initialize global composer: Composer could not find the config file: /.composer/composer.json

Reading /app/vendor/composer/installed.json
Loading plugin Symfony\Flex\Flex (from symfony/flex)
Loading plugin Symfony\Component\Runtime\Internal\ComposerPlugin (from symfony/runtime)
Generating optimized autoload files
Class App\Value\ReportExecutionStatus:string located in ./src/Value/ReportExecutionStatus.php does not comply with psr-4 autoloading standard. Skipping.
> post-autoload-dump: Symfony\Component\Runtime\Internal\ComposerPlugin->updateAutoloadFile
Generated optimized autoload files containing 7212 classes

And I expected this to happen:

No warning, ReportExecutionStatus should be detected as valid PSR-4 and written to autoload_classmap.php.