psalm.xml

<?xml version="1.0"?>
<psalm
    findUnusedPsalmSuppress="true"
    findUnusedCode="true"
    findUnusedVariablesAndParams="true"
    strictBinaryOperands="true"
    errorLevel="1"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="https://getpsalm.org/schema/config"
    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
>
    <projectFiles>
        <ignoreFiles>
            <directory name="vendor"/>
        </ignoreFiles>
        <directory name="static-analysis"/>
        <directory name="src"/>
        <directory name="tests"/>
    </projectFiles>

    <issueHandlers>
        <ImpureStaticProperty>
            <errorLevel type="suppress">
                <!-- the Money object uses internal static properties to cache the calculator
                     that is in use, as well as the calculators that are available. This is
                     not supposed to change at runtime, and therefore the VO can still be
                     considered immutable -->
                <file name="src/Money.php"/>
            </errorLevel>
        </ImpureStaticProperty>

        <ImpureVariable>
            <errorLevel type="suppress">
                <!-- @TODO is this even needed? -->
                <!-- we can safely access $this->amount within Money -->
                <file name="src/Money.php"/>
            </errorLevel>
        </ImpureVariable>

        <InternalClass>
            <errorLevel type="suppress">
                <!-- Internal symbols of the library can be used from within the test suite -->
                <directory name="tests"/>
            </errorLevel>
        </InternalClass>

        <InternalMethod>
            <errorLevel type="suppress">
                <!-- Internal symbols of the library can be used from within the test suite -->
                <directory name="tests"/>
            </errorLevel>
        </InternalMethod>

        <PossiblyUnusedMethod>
            <errorLevel type="suppress">
                <!-- calculators are not swapped at runtime in our test suite - they are a dead/deprecated concept
                     that will likely be removed, but we generally do not register calculators manually -->
                <referencedMethod name="Money\Exchange\ReversedCurrenciesExchange::registerCalculator"/>
                <referencedMethod name="Money\Exchange\IndirectExchange::registerCalculator"/>
                <referencedMethod name="Money\Money::registerCalculator"/>
            </errorLevel>
        </PossiblyUnusedMethod>
    </issueHandlers>

    <plugins>
        <pluginClass class="Psalm\PhpUnitPlugin\Plugin"/>
    </plugins>
</psalm>