ruleset.xml

<ruleset name="GOV.UK Pay PMD Rules"
        xmlns="http://pmd.sourceforge.net/ruleset/2.0.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://pmd.sourceforge.net/ruleset/2.0.0 https://pmd.sourceforge.io/ruleset_2_0_0.xsd">

    <description>GOV.UK Pay PMD rules, primarily for use by Codacy</description>

    <rule ref="category/java/bestpractices.xml">
        <exclude name="AbstractClassWithoutAbstractMethod"/>

        <!-- Some tests use hard-coded IP addresses --> 
        <exclude name="AvoidUsingHardCodedIP"/>

        <exclude name="GuardLogStatement"/>

        <exclude name="JUnitAssertionsShouldIncludeMessage"/>

        <exclude name="JUnitTestContainsTooManyAsserts"/>

        <!-- Some tests e.g. REST Assured do not use asserts -->
        <exclude name="JUnitTestsShouldIncludeAssert"/>
    </rule>

    <rule ref="category/java/codestyle.xml">
        <!-- Some integration test classes have no constructors -->
        <exclude name="AtLeastOneConstructor"/>

        <exclude name="DefaultPackage"/>

        <!-- Some Pact test superclasses use `@State` on empty methods to make them no-ops -->
        <exclude name="EmptyMethodInAbstractClassShouldBeAbstract"/>

        <exclude name="LocalVariableCouldBeFinal"/>

        <exclude name="LongVariable"/>

        <exclude name="MethodArgumentCouldBeFinal"/>

        <exclude name="OnlyOneReturn"/>

        <!-- Would flag `var thing = dao.findThing().orElseThrow(() -> new Exception("Fail early if not found!"));` -->
        <exclude name="PrematureDeclaration"/>

        <exclude name="ShortClassName"/>

        <exclude name="ShortVariable"/>

        <exclude name="TooManyStaticImports"/>

        <!-- JPA requires entities to have a no-args constructor — we don’t want to rely on the default constructor
             because it’s easy to add another constructor that causes the default one to go away without realising,
             causing JPA problems at run time, so we instead explicitly include a no-args constructor even though it’s
             “unnecessary” -->
        <exclude name="UnnecessaryConstructor"/>

        <!-- Sometimes we use strictly unnecessary parentheses for clarity e.g. `if ((a && b) || c)` -->
        <exclude name="UselessParentheses"/>

        <!-- Too rigid for us: since we deal with money, we might represent £125.50 as `125_50` -->
        <exclude name="UseUnderscoresInNumericLiterals"/>

        <!-- Deprecated rules -->
        <exclude name="AbstractNaming"/>
        <exclude name="AvoidFinalLocalVariable"/>
        <exclude name="AvoidPrefixingMethodParameters"/>
        <exclude name="ForLoopsMustUseBraces"/>
        <exclude name="IfElseStmtsMustUseBraces"/>
        <exclude name="IfStmtsMustUseBraces"/>
        <exclude name="MIsLeadingVariableName"/>
        <exclude name="SuspiciousConstantFieldName"/>
        <exclude name="VariableNamingConventions"/>
        <exclude name="WhileLoopsMustUseBraces"/>
    </rule>

    <rule ref="category/java/codestyle.xml/ClassNamingConventions">
        <properties>
            <!-- We don’t require utility classes to end with “Utils” or “Helper” -->
            <property name="utilityClassPattern" value="[A-Z][a-zA-Z0-9]+"/>
        </properties>
    </rule>

    <rule ref="category/java/codestyle.xml/LinguisticNaming">
        <properties>
            <!-- A method named `isNotString()` might return a `Function` rather than a `boolean` -->
            <property name="checkBooleanMethod" value="false"/>

            <!-- A test that tests a getter may start with “get” but have a `void` return type -->
            <property name="checkGetters" value="false"/>
        </properties>
    </rule>

    <rule ref="category/java/codestyle.xml/MethodNamingConventions">
        <properties>
            <!-- Some test method names use underscores for readability -->
            <property name="junit4TestPattern" value="[a-z][a-zA-Z0-9_]*[a-zA-Z0-9]"/>
        </properties>
    </rule>

    <rule ref="category/java/errorprone.xml">
        <exclude name="AvoidDuplicateLiterals"/>

        <exclude name="AvoidFieldNameMatchingMethodName"/>

        <exclude name="AvoidFieldNameMatchingTypeName"/>

        <!-- Would flag fields that store injected dependencies etc. -->
        <exclude name="BeanMembersShouldSerialize"/>

        <exclude name="DataflowAnomalyAnalysis"/>

        <!-- We never use Java serialisation -->
        <exclude name="MissingSerialVersionUID"/>

        <exclude name="NullAssignment"/>

        <!-- Would flag some Pact tests -->
        <exclude name="TestClassWithoutTestCases"/>

        <!-- Deprecated rules -->
        <exclude name="LoggerIsNotStaticFinal"/>
    </rule>

    <rule ref="category/xml/errorprone.xml"/>

</ruleset>