checkstyle.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE module PUBLIC
    "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
    "http://www.puppycrawl.com/dtds/configuration_1_3.dtd">

<!-- This is a checkstyle configuration file. For descriptions of
what the following rules do, please see the checkstyle configuration
page at http://checkstyle.sourceforge.net/config.html -->

<module name="Checker">
  <property name="haltOnException" value="false" />

  <!-- Exclude module-info.java from checks, as CheckStyle does not presently support it -->
  <module name="BeforeExecutionExclusionFileFilter">
    <property name="fileNamePattern" value="module\-info\.java$"/>
  </module>

  <!-- Custom filter for Azure SDKs. -->
  <module name="com.azure.tools.checkstyle.filters.AzureSdkFilter"/>

  <module name="SuppressionFilter">
    <property name="file" value="${samedir}/checkstyle-suppressions.xml"/>
    <property name="optional" value="true"/>
  </module>

  <module name="Header">
    <property name="header"
              value="// Copyright (c) Microsoft Corporation. All rights reserved.\n// Licensed under the MIT License."/>
    <property name="fileExtensions" value="java"/>
  </module>

  <!-- Checks that there are no tab characters in the file. -->
  <module name="FileTabCharacter" />

  <module name="NewlineAtEndOfFile" />

  <module name="RegexpSingleline">
    <!-- Checks that FIXME is not used in comments.  TODO is preferred. -->
    <property name="format" value="((//.*)|(\*.*))FIXME"/>
    <property name="message" value='TODO is preferred to FIXME.  e.g. "TODO(johndoe): Refactor when v2 is released."'/>
  </module>

  <module name="RegexpSingleline">
    <!-- Checks that TODOs are named.  (Actually, just that they are followed by an open paren. -->
    <property name="format" value="((//.*)|(\*.*))TODO [^(]"/>
    <property name="message" value='All TODOs should be named.  e.g. "TODO (johndoe): Refactor when v2 is released."'/>
  </module>

  <!-- Checks that a package-info.java file exists for each package. -->
  <!-- See http://checkstyle.sf.net/config_javadoc.html#JavadocPackage -->
  <module name="JavadocPackage"/>

  <!-- Enforce line length to 120 char -->
  <module name="LineLength">
    <property name="max" value="120"/>
    <!-- Allow codeSnippet to override max line length -->
    <!-- Allow comment with single word to override max line length -->
    <property name="ignorePattern" value=".*(\{@codesnippet.*\}|&lt;a href)|^ *\* *[^ ]+$||http://|https://|^ *\* *[^ ]+$"/>
  </module>

  <!-- All Java AST specific tests live under TreeWalker module. -->
  <module name="TreeWalker">

    <!-- IMPORT CHECKS -->
    <!-- See http://checkstyle.sf.net/config_import.html -->
    <module name="AvoidStarImport"/>
    <module name="IllegalImport">
      <property name="regexp" value="true"/>
      <property name="illegalPkgs" value="^(com\.)?sun\.\w*, ^io.opentelemetry"/>
    </module>
    <module name="RedundantImport"/>
    <module name="UnusedImports"/>

    <!-- NAMING CHECKS -->
    <!-- See http://checkstyle.sf.net/config_naming.html -->
    <module name="ConstantName"/>
    <module name="LocalFinalVariableName"/>
    <module name="LocalVariableName"/>
    <module name="MemberName"/>
    <module name="MethodName">
      <!-- Use default MethodName but block the use of 'builder' as method name -->
      <property name="format" value="(?=^[a-z][a-zA-Z0-9]*$)(?!^(?i)builder$)"/>
      <!-- allow the name on private methods  -->
      <property name="applyToPrivate" value="false"/>
    </module>
    <module name="PackageName"/>
    <module name="ParameterName"/>
    <module name="StaticVariableName"/>
    <module name="TypeName"/>

    <module name="TypeNameCheck">
      <!-- Validates static, final fields against the
      expression "^[A-Z][a-zA-Z0-9]*$". -->
      <metadata name="altname" value="TypeName"/>
      <property name="severity" value="warning"/>
    </module>

    <module name="ConstantNameCheck">
      <!-- Validates non-private, static, final fields against the supplied
      public/package final fields "^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$". -->
      <metadata name="altname" value="ConstantName"/>
      <property name="applyToPublic" value="true"/>
      <property name="applyToProtected" value="true"/>
      <property name="applyToPackage" value="true"/>
      <property name="applyToPrivate" value="false"/>
      <property name="format" value="^([A-Z][A-Z0-9]*(_[A-Z0-9]+)*|FLAG_.*)$"/>
      <message key="name.invalidPattern"
               value="Variable ''{0}'' should be in ALL_CAPS (if it is a constant) or be private (otherwise)."/>
      <property name="severity" value="warning"/>
    </module>

    <module name="MissingDeprecated"/>

    <module name="StaticVariableNameCheck">
      <!-- Validates static, non-final fields against the supplied
      expression "^[a-z][a-zA-Z0-9]*_?$". -->
      <metadata name="altname" value="StaticVariableName"/>
      <property name="applyToPublic" value="true"/>
      <property name="applyToProtected" value="true"/>
      <property name="applyToPackage" value="true"/>
      <property name="applyToPrivate" value="true"/>
      <property name="format" value="^[a-z][a-zA-Z0-9]*_?$"/>
      <property name="severity" value="warning"/>
    </module>

    <module name="MemberNameCheck">
      <!-- Validates non-static members against the supplied expression. -->
      <metadata name="altname" value="MemberName"/>
      <property name="applyToPublic" value="true"/>
      <property name="applyToProtected" value="true"/>
      <property name="applyToPackage" value="true"/>
      <property name="applyToPrivate" value="true"/>
      <property name="format" value="^[a-z][a-zA-Z0-9]*$"/>
      <property name="severity" value="warning"/>
    </module>

    <module name="EqualsAvoidNullCheck"/>

    <module name="MethodNameCheck">
      <!-- Validates identifiers for method names. -->
      <metadata name="altname" value="MethodName"/>
      <property name="format" value="^[a-z][a-zA-Z0-9]*(_[a-zA-Z0-9]+)*$"/>
      <property name="severity" value="warning"/>
    </module>

    <module name="ParameterName">
      <!-- Validates identifiers for method parameters against the
        expression "^[a-z][a-zA-Z0-9]*$". -->
      <property name="severity" value="warning"/>
    </module>

    <module name="LocalFinalVariableName">
      <!-- Validates identifiers for local final variables against the
        expression "^[a-z][a-zA-Z0-9]*$". -->
      <property name="severity" value="warning"/>
    </module>

    <module name="LocalVariableName">
      <!-- Validates identifiers for local variables against the
        expression "^[a-z][a-zA-Z0-9]*$". -->
      <property name="severity" value="warning"/>
    </module>

    <!-- LENGTH and CODING CHECKS -->
    <module name="LeftCurly">
      <!-- Checks for placement of the left curly brace ('{'). -->
      <property name="severity" value="warning"/>
    </module>

    <module name="RightCurly">
      <!-- Checks right curlies on CATCH, ELSE, and TRY blocks are on
      the same line. e.g., the following example is fine:
      <pre>
        if {
          ...
        } else
      </pre>
      -->
      <!-- This next example is not fine:
      <pre>
        if {
          ...
        }
        else
      </pre>
      -->
      <property name="option" value="same"/>
      <property name="severity" value="warning"/>
    </module>

    <!-- Checks for braces around if and else blocks -->
    <module name="NeedBraces">
      <property name="tokens" value="LITERAL_IF, LITERAL_ELSE, LITERAL_FOR, LITERAL_WHILE, LITERAL_DO"/>
    </module>

    <module name="UpperEll">
      <!-- Checks that long constants are defined with an upper ell.-->
      <property name="severity" value="error"/>
    </module>

    <module name="FallThrough">
      <!-- Warn about falling through to the next case statement.  Similar to
      javac -Xlint:fallthrough, but the check is suppressed if a single-line comment
      on the last non-blank line preceding the fallen-into case contains 'fall through' (or
      some other variants which we don't publicized to promote consistency).
      -->
      <property name="reliefPattern"
                value="fall through|Fall through|fallthru|Fallthru|falls through|Falls through|fallthrough|Fallthrough|No break|NO break|no break|continue on"/>
      <property name="severity" value="error"/>
    </module>

    <!-- WHITESPACE CHECKS -->
    <module name="Indentation">
      <property name="basicOffset" value="4"/>
      <property name="braceAdjustment" value="0"/>
      <property name="caseIndent" value="4"/>
      <property name="throwsIndent" value="4"/>
      <property name="lineWrappingIndentation" value="4"/>
      <property name="arrayInitIndent" value="4"/>
    </module>

    <!-- Checks for whitespace                               -->
    <!-- See http://checkstyle.sf.net/config_whitespace.html -->
    <module name="EmptyForIteratorPad"/>
    <module name="MethodParamPad"/>
    <module name="NoWhitespaceAfter">
      <property name="tokens" value="INC,DEC,UNARY_MINUS,UNARY_PLUS,BNOT,LNOT,DOT,ARRAY_DECLARATOR,INDEX_OP"/>
    </module>
    <module name="NoWhitespaceBefore"/>
    <module name="OperatorWrap"/>
    <module name="ParenPad"/>
    <module name="TypecastParenPad"/>
    <module name="WhitespaceAfter"/>
    <module name="WhitespaceAround">
      <!-- Common for Autorest to generate empty constructors, methods, and types. -->
      <property name="allowEmptyConstructors" value="true"/>
      <property name="allowEmptyMethods" value="true"/>
      <property name="allowEmptyTypes" value="true"/>
      <property name="allowEmptyLambdas" value="true"/>
    </module>

    <!-- Modifier Checks                                    -->
    <!-- See http://checkstyle.sf.net/config_modifiers.html -->
    <module name="ModifierOrder"/>
    <module name="RedundantModifier"/>

    <!-- Checks for blocks. You know, those {}'s         -->
    <!-- See http://checkstyle.sf.net/config_blocks.html -->
    <module name="AvoidNestedBlocks"/>
    <module name="EmptyBlock"/>

    <!-- Checks for common coding problems               -->
    <!-- See http://checkstyle.sf.net/config_coding.html -->
    <module name="EmptyStatement"/>
    <module name="EqualsHashCode"/>
    <module name="IllegalInstantiation"/>
    <module name="InnerAssignment"/>

    <!-- Updated on 03/17/2014: -->
    <!-- Added ignore. Code is generated so magic numbers are not a largish issue. -->
    <!-- <module name="MagicNumber" /> -->
    <module name="MissingSwitchDefault"/>
    <module name="SimplifyBooleanExpression"/>
    <module name="SimplifyBooleanReturn"/>

    <!-- Checks for class design                         -->
    <!-- See http://checkstyle.sf.net/config_design.html -->
    <module name="FinalClass"/>
    <module name="InterfaceIsType"/>
    <module name="VisibilityModifier">
      <property name="protectedAllowed" value="true"/>
      <property name="packageAllowed" value="true"/>
    </module>

    <!-- Miscellaneous other checks.                   -->
    <!-- See http://checkstyle.sf.net/config_misc.html -->
    <module name="ArrayTypeStyle"/>

    <!--Checks for package naming and name length limit. Package names have to starting with either-->
    <!--'com.microsoft.azure', 'com.azure', or 'io.clientcore' and then the extension names start with-->
    <!--characters 'a' to 'z' and only contains 'a' to 'z' or '0' to '9' with no more than 32 characters-->
    <!--and the package names should be no more than 80 characters.-->
    <module name="PackageName">
      <property name="format" value="^(?=.{9,80}$)((com.microsoft|com.azure|io.clientcore)(\.[a-z][a-z0-9]{1,31})*)+$"/>
    </module>

    <!-- Javadoc checks                                   -->
    <!-- See http://checkstyle.sf.net/config_javadoc.html -->
    <module name="JavadocMethod">
      <property name="accessModifiers" value="public, protected"/>
    </module>
    <module name="MissingJavadocMethod"/>
    <module name="MissingJavadocType"/>
    <module name="MissingJavadocPackage"/>

    <!-- Verifies that all throws in the public API have JavaDocs explaining why and when they are thrown. -->
    <!-- The check verifies both checked (in the throws clause) and unchecked throws -->
    <module name="com.azure.tools.checkstyle.checks.JavadocThrowsChecks"/>

    <!-- CUSTOM CHECKS -->
    <!-- Checks for the public API that should
    1) not return classes in the implementation package
    2) no class of implementation package as method's parameters -->
    <module name="com.azure.tools.checkstyle.checks.NoImplInPublicAPI"/>

    <!-- CUSTOM CHECKS -->
    <!-- Verify the classes with annotation @ServiceClient should have following rules:
    1) No public or protected constructors
    2) No public static method named 'builder'
    3) Since these classes are supposed to be immutable, all fields in the service client classes should be final.

    Also, verify all methods that have a @ServiceMethod annotation in a class annotated with @ServiceClient should
    follow below rules:
    1) Follows method naming pattern. Refer to Java Spec.
    2) Methods should not have "Async" added to the method name
    3) The return type of async and sync clients should be as per guidelines:
      3.1) The return type for async collection should be of type? extends PagedFlux
      3.2) The return type for async single value should be of type? extends Mono
      3.3) The return type for sync collection should be of type? extends PagedIterable
      3.4) The return type for sync single value should be of type? extends Response -->
    <module name="com.azure.tools.checkstyle.checks.ServiceClientCheck"/>

    <!-- CUSTOM CHECKS -->
    <!-- Checks for no external dependency exposed in the public API.
    We should only return types, and accept argument types, that are from the com.azure namespace.
    All other types should have suppression added if required. -->
    <module name="com.azure.tools.checkstyle.checks.ExternalDependencyExposedCheck"/>

    <!-- CUSTOM CHECKS -->
    <!-- The @ServiceClientBuilder class should have the following rules:
    1) All service client builder should be named <ServiceName>ClientBuilder and annotated with @ServiceClientBuilder.
    2) Has a method 'buildClient()' to build a synchronous client,
    3) Has a method 'buildAsyncClient()' to build an asynchronous client -->
    <module name="com.azure.tools.checkstyle.checks.ServiceClientBuilderCheck"/>

    <!-- CUSTOM CHECKS -->
    <!-- The @ServiceInterface class should have the following rules:
    1) The annotation property 'name' should be non-empty
    2) The length of value of property 'name' should be less than 20 characters and without space -->
    <module name="com.azure.tools.checkstyle.checks.ServiceInterfaceCheck"/>

    <!-- CUSTOM CHECKS -->
    <!-- The @Immutable class should have the following rules: -->
    <!-- 1) All public and protected fields must be final -->
    <!-- 2) No public or protected setters -->
    <module name="com.azure.tools.checkstyle.checks.ImmutableClassCheck"/>

    <!-- CUSTOM CHECKS -->
    <!-- Verify the whenever a field is assigned just once in constructor to be final -->
    <module name="com.azure.tools.checkstyle.checks.EnforceFinalFieldsCheck"/>

    <!-- CUSTOM CHECKS -->
    <!-- Javadoc format: 'param / return / throws' descriptions text should only have one space character after the
     parameter name or return -->
    <module name="com.azure.tools.checkstyle.checks.JavaDocFormatting"/>

    <!-- CUSTOM CHECKS -->
    <!-- Must use 'logger.logAndThrow' but not directly calling 'throw exception' -->
    <module name="com.azure.tools.checkstyle.checks.ThrowFromClientLoggerCheck"/>

    <!-- CUSTOM CHECKS -->
    <!-- Any class that implements the HttpPipelinePolicy interface should:
    1) Must be a public class.
    2) Not in an implementation package or sub-package. -->
    <module name="com.azure.tools.checkstyle.checks.HttpPipelinePolicyCheck"/>

    <!-- CUSTOM CHECKS -->
    <!-- Javadoc inline check should:
    1) Use {@codesnippet ...} instead of '<code>', '<pre>', or '{@code ...}' if these tags span multiple lines.
       Inline code sample are fine as-is.
    2) No check on class-level Javadoc. -->
    <!-- This check was removed as it causes more noise than fixes. The purpose of this check was to move away from -->
    <!-- using <code>, <pre>, and {@code} tags while we were on-boarding codesnippets. These tags have since been   -->
    <!-- removed and codesnippets are expected.                                                                     -->
    <!-- <module name="com.azure.tools.checkstyle.checks.JavadocInlineTagCheck"/> -->

    <!-- CUSTOM CHECKS -->
    <!-- {@codesnippet ...} description should match naming pattern requirement below:
    1) Package, class and method names should be concatenated by dot '.'. Ex. packageName.className.methodName
    2) Methods arguments should be concatenated by dash '-'. Ex. string-string  for methodName(String s, String s2)
    3) Use '#' to concatenate 1) and 2), ex packageName.className.methodName#string-string -->
    <module name="com.azure.tools.checkstyle.checks.JavadocCodeSnippetCheck"/>

    <!--CUSTOM CHECKS-->
    <!-- Good Logging Practice
    1) ClientLogger in public API should all named 'logger', public API classes are those classes that are declared
       as public and that do not exist in an implementation package or subpackage.
    2) ClientLogger should be non-static instance logger
    3) Should not use any external logger class, only use ClientLogger. No slf4j, log4j, or other logging imports are allowed.
      'System.out' and 'System.err' is not allowed as well.
    4) All classes should use ClientLogger as logger only but except ClientLogger itself -->
    <module name="com.azure.tools.checkstyle.checks.GoodLoggingCheck"/>

    <!-- CUSTOM CHECKS -->
    <!-- Public API classes should follow Camelcase rules: -->
    <!-- 1. ClassName -->
    <!-- 2. methodName -->
    <!-- 3. variableName -->
    <!-- 4. longerVariableOrMethodName -->
    <module name="com.azure.tools.checkstyle.checks.DenyListedWordsCheck">
      <property name="denyListedWords" value="URL, HTTP, XML, JSON, SAS, CPK, API" />
    </module>

    <!-- CUSTOM CHECKS -->
    <!-- Fluent method checks:
    (1) A method returns an instance of the class, and that have one parameter,
    (2) should not start with the words in the avoidStartWords list.-->
    <!-- <module name="com.azure.tools.checkstyle.checks.FluentMethodNameCheck">-->
    <!--    <property name="avoidStartWords" value="with,set"/>-->
    <!-- </module>-->

    <!-- CUSTOM CHECKS -->
    <!-- Ensures caught exceptions are included as exception cause in subsequently thrown exception -->
    <module name="com.azure.tools.checkstyle.checks.UseCaughtExceptionCauseCheck"/>

    <module name="com.azure.tools.checkstyle.checks.StepVerifierCheck"/>
  </module>
</module>