phpcs.xml

<?xml version="1.0"?>
<ruleset xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" name="PHP_CodeSniffer" xsi:noNamespaceSchemaLocation="phpcs.xsd">
    <description>Coding Standards</description>

    <!-- Inspect files in the /src folder -->
    <file>src</file>

    <!-- Run in verbose mode and specify the precise rule that failed in output -->
    <arg value="sv"/>
    <arg name="colors"/>

    <!-- Use PSR-12 -->
    <rule ref="PSR12">
        <!-- Exclude function not in camel caps format, to avoid breaking changes -->
        <exclude name="PSR1.Methods.CamelCapsMethodName.NotCamelCaps" />

        <!-- Don't require spacing after header block -->
        <exclude name="PSR12.Files.FileHeader.SpacingAfterBlock" />

        <!-- Permit else if over elseif -->
        <exclude name="PSR2.ControlStructures.ElseIfDeclaration.NotAllowed" />
    </rule>

    <!-- Use Squiz -->
    <rule ref="Squiz">
        <!-- Don't require a package tag -->
        <exclude name="Squiz.Commenting.FileComment.PackageTagOrder" />
        <exclude name="Squiz.Commenting.FileComment.MissingPackageTag" />
        <exclude name="Squiz.Commenting.FileComment.MissingSubpackageTag" />

        <!-- Exclude "Class found in ".php" file; use ".inc" extension instead" -->
        <exclude name="Squiz.Files.FileExtension.ClassFound" />

        <!-- Exclude PascalCase format for class name, to avoid breaking changes -->
        <exclude name="Squiz.Classes.ValidClassName.NotCamelCaps" />

        <!-- Exclude variable naming, to avoid breaking changes -->
        <exclude name="Squiz.NamingConventions.ValidVariableName.MemberNotCamelCaps" />
        <exclude name="Squiz.NamingConventions.ValidVariableName.NotCamelCaps" />
        <exclude name="Squiz.NamingConventions.ValidFunctionName.ScopeNotCamelCaps" />

        <!-- Allow implicit true and false comparisons -->
        <exclude name="Squiz.Operators.ComparisonOperatorUsage.ImplicitTrue" />
        <exclude name="Squiz.Operators.ComparisonOperatorUsage.NotAllowed" />

        <!-- Don't require // end comments after each function, or Author / Copyright tags -->
        <exclude name="Squiz.Commenting.ClosingDeclarationComment.Missing" />
        <exclude name="Squiz.Commenting.FileComment.IncorrectAuthor" />
        <exclude name="Squiz.Commenting.FileComment.MissingCopyrightTag" />
        <exclude name="Squiz.Commenting.PostStatementComment" />

        <!-- Permit inline if statements -->
        <exclude name="Squiz.PHP.DisallowInlineIf.Found" />
        <exclude name="Squiz.PHP.DisallowComparisonAssignment" />

        <!-- Don't require various newlines and spacing before and after functions -->
        <exclude name="Squiz.WhiteSpace.FunctionSpacing.AfterLast" />
        <exclude name="Squiz.WhiteSpace.FunctionSpacing.After" />
        <exclude name="Squiz.WhiteSpace.FunctionClosingBraceSpace.SpacingBeforeClose" />
        <exclude name="Squiz.WhiteSpace.MemberVarSpacing.FirstIncorrect" />

        <!-- Permit padding surrounding a concat operator -->
        <exclude name="Squiz.Strings.ConcatenationSpacing.PaddingFound" />

        <!-- Don't require break to align with switch -->
        <exclude name="Squiz.ControlStructures.SwitchDeclaration.BreakIndent" />

        <!-- Allow use of is_null() -->
        <exclude name="Generic.PHP.ForbiddenFunctions" />
    </rule>

    <!-- Permit slightly longer line lengths -->
    <rule ref="Generic.Files.LineLength">
        <properties>
            <property name="lineLimit" value="150"/>
            <property name="absoluteLineLimit" value="0"/>
        </properties>
    </rule>
</ruleset>