psalm.xml

<?xml version="1.0"?>
<psalm
    errorLevel="4"
    resolveFromConfigFile="true"
    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>
        <directory name="src" />
        <ignoreFiles>
            <directory name="vendor" />
        </ignoreFiles>
    </projectFiles>

    <issueHandlers>
        <LessSpecificReturnType errorLevel="error" />

        <!-- level 3 issues - slightly lazy code writing, but provably low false-negatives -->
        <DeprecatedMethod errorLevel="error" />

        <MissingClosureReturnType errorLevel="error" />
        <MissingReturnType errorLevel="error" />
        <MissingPropertyType errorLevel="error" />
        <InvalidDocblock errorLevel="error" />
        <MisplacedRequiredParam errorLevel="error" />

        <PropertyNotSetInConstructor errorLevel="error" />
        <MissingConstructor errorLevel="error" />
    </issueHandlers>

</psalm>