Uncaught Exception: Could not locate trait statement

[kelunik]

git clone https://github.com/amphp/amp
cd amp
./vendor/bin/psalm.phar --init

Psalm 3.9.4@352bd3f5c5789db04e4010856c2f4e01ed354f4e

Running --init on Amp currently isn't possible. This is due to the conditional definition of our CallableMaker trait. Can I work around this or could Psalm be extended to evaluate PHP_VERSION_ID and pick the right version?

[psalm-github-bot]

Hey @kelunik, can you reproduce the issue on https://psalm.dev ?

[kelunik]

Not really, it says ERROR: DuplicateClass - 56:11 - Class Amp\CallableMaker has already been defined there. https://psalm.dev/r/a6601ab157

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/a6601ab157

<?php

namespace Amp;

// @codeCoverageIgnoreStart
if (\PHP_VERSION_ID < 70100) {
    trait CallableMaker
    {
        /** @var \ReflectionClass */
        private static $__reflectionClass;

        /** @var \ReflectionMethod[] */
        private static $__reflectionMethods = [];

        /**
         * Creates a callable from a protected or private instance method that may be invoked by callers requiring a
         * publicly invokable callback.
         *
         * @param string $method Instance method name.
         *
         * @return callable
         */
        private function callableFromInstanceMethod(string $method): callable
        {
            if (!isset(self::$__reflectionMethods[$method])) {
                if (self::$__reflectionClass === null) {
                    self::$__reflectionClass = new \ReflectionClass(self::class);
                }
                self::$__reflectionMethods[$method] = self::$__reflectionClass->getMethod($method);
            }

            return self::$__reflectionMethods[$method]->getClosure($this);
        }

        /**
         * Creates a callable from a protected or private static method that may be invoked by methods requiring a
         * publicly invokable callback.
         *
         * @param string $method Static method name.
         *
         * @return callable
         */
        private static function callableFromStaticMethod(string $method): callable
        {
            if (!isset(self::$__reflectionMethods[$method])) {
                if (self::$__reflectionClass === null) {
                    self::$__reflectionClass = new \ReflectionClass(self::class);
                }
                self::$__reflectionMethods[$method] = self::$__reflectionClass->getMethod($method);
            }

            return self::$__reflectionMethods[$method]->getClosure();
        }
    }
} else {
    trait CallableMaker
    {
        /**
         * @deprecated Use \Closure::fromCallable() instead of this method in PHP 7.1.
         */
        private function callableFromInstanceMethod(string $method): callable
        {
            return \Closure::fromCallable([$this, $method]);
        }

        /**
         * @deprecated Use \Closure::fromCallable() instead of this method in PHP 7.1.
         */
        private static function callableFromStaticMethod(string $method): callable
        {
            return \Closure::fromCallable([self::class, $method]);
        }
    }
} // @codeCoverageIgnoreEnd

Psalm output (using commit 60fb392):

ERROR: DuplicateClass - 56:11 - Class Amp\CallableMaker has already been defined in /var/www/vhosts/psalm.dev/httpdocs/src/../src/somefile.php

[weirdan]

Similar bug reported on phpunit plugin: psalm/psalm-plugin-phpunit#56, also involving conditionally defined trait: https://github.com/symfony/symfony/blob/14b825b24fece6a4853d7bf537b86df88d3bfcc1/src/Symfony/Component/Validator/Test/ForwardCompatTestTrait.php

[muglug]

I'll release a fix today for this that uses reflection to determine the winner when there's more than one trait defined in a given file.

[kelunik]

@muglug Thanks for the quick fix. Now I get the DuplicateClass as on psalm.dev. I guess this error needs to be suppressed by me now?

ERROR: DuplicateClass - lib/CallableMaker.php:56:11 - Class Amp\CallableMaker has already been defined in /home/kelunik/GitHub/amphp/amp/lib/CallableMaker.php
    trait CallableMaker

[kelunik]

Adding @psalm-suppress DuplicateClass to both definitions doesn't seem to help.

[muglug]

You can suppress that in your psalm.xml:

    <issueHandlers>
        <DuplicateClass>
            <errorLevel type="suppress">
                <file name="lib/CallableMaker.php" />
            </errorLevel>
        </DuplicateClass>
    </issueHandlers>

[kelunik]

Thanks!