scalastyle-config.xml

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 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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  -->

<!--
If you wish to turn off checking for a section of code, you can put a comment in the source
before and after the section, with the following syntax:
  // scalastyle:off
  ...  // stuff that breaks the styles
  // scalastyle:on
You can also disable only one rule, by specifying its rule id, as specified in:
  http://www.scalastyle.org/rules-0.7.0.html
  // scalastyle:off no.finalize
  override def finalize(): Unit = ...
  // scalastyle:on no.finalize
This file is divided into 3 sections:
 (1) rules that we enforce.
 (2) rules that we would like to enforce, but haven't cleaned up the codebase to turn on yet
     (or we need to make the scalastyle rule more configurable).
 (3) rules that we don't want to enforce.
-->

<scalastyle>
    <name>Scalastyle standard configuration</name>

    <!-- ================================================================================ -->
    <!--                               rules we enforce                                   -->
    <!-- ================================================================================ -->

    <check level="error" class="org.scalastyle.file.HeaderMatchesChecker" enabled="true">
        <parameters>
            <parameter name="header"><![CDATA[/*
 * Copyright (c) 2019 The StreamX Project
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */]]></parameter>
        </parameters>
    </check>

    <check level="error" class="org.scalastyle.file.FileTabChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.SpacesAfterPlusChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.SpacesBeforePlusChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.ClassNamesChecker" enabled="true">
        <parameters>
            <parameter name="regex"><![CDATA[[A-Z][A-Za-z]*]]></parameter>
        </parameters>
    </check>

    <check level="error" class="org.scalastyle.scalariform.ObjectNamesChecker" enabled="true">
        <parameters>
            <parameter name="regex"><![CDATA[[A-Z][A-Za-z]*]]></parameter>
        </parameters>
    </check>

    <check level="error" class="org.scalastyle.scalariform.PackageObjectNamesChecker" enabled="true">
        <parameters>
            <parameter name="regex"><![CDATA[^[a-z][A-Za-z]*$]]></parameter>
        </parameters>
    </check>

    <check level="error" class="org.scalastyle.scalariform.ParameterNumberChecker" enabled="true">
        <parameters>
            <parameter name="maxParameters"><![CDATA[15]]></parameter>
        </parameters>
    </check>

    <check level="error" class="org.scalastyle.scalariform.EqualsHashCodeChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.IllegalImportsChecker" enabled="true">
        <parameters>
            <parameter name="illegalImports"><![CDATA[sun._,java.awt._]]></parameter>
        </parameters>
        <customMessage>Illegal import of sun._ or java.awt._</customMessage>
    </check>

    <check level="error" class="org.scalastyle.scalariform.IllegalImportsChecker" enabled="true">
        <parameters>
            <parameter name="illegalImports"><![CDATA[scala.collection.Seq,scala.collection.IndexedSeq]]></parameter>
        </parameters>
        <customMessage><![CDATA[
          Don't import scala.collection.Seq and scala.collection.IndexedSeq as it may bring some problems with cross-build between Scala 2.12 and 2.13.
          Please refer below page to see the details of changes around Seq / IndexedSeq.
          https://docs.scala-lang.org/overviews/core/collections-migration-213.html
          If you really need to use scala.collection.Seq or scala.collection.IndexedSeq, please use the fully-qualified name instead.
        ]]>
        </customMessage>
    </check>

    <!-- We cannot turn the following two on, because it'd fail a lot of string interpolation use cases. -->
    <!-- Ideally the following two rules should be configurable to rule out string interpolation. -->
    <check level="error" class="org.scalastyle.scalariform.NoWhitespaceBeforeLeftBracketChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.NoWhitespaceAfterLeftBracketChecker" enabled="true"/>

    <!-- Doesn't seem super big deal here ... -->
    <check level="error" class="org.scalastyle.scalariform.NoCloneChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.NoFinalizeChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.CovariantEqualsChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.StructuralTypeChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.UppercaseLChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.IfBraceChecker" enabled="true">
        <parameters>
            <parameter name="singleLineAllowed"><![CDATA[true]]></parameter>
            <parameter name="doubleLineAllowed"><![CDATA[true]]></parameter>
        </parameters>
    </check>

    <!-- Single Space between ')' and '{' -->
    <check customId="SingleSpaceBetweenRParenAndLCurlyBrace" level="error" class="org.scalastyle.file.RegexChecker" enabled="true">
        <parameters>
            <parameter name="regex">\)\{</parameter>
        </parameters>
        <customMessage><![CDATA[
          Single Space between ')' and `{`.
        ]]>
        </customMessage>
    </check>

    <check customId="GuavaToStringHelper" level="error" class="org.scalastyle.file.RegexChecker" enabled="true">
        <parameters>
            <parameter name="regex">Objects.toStringHelper</parameter>
        </parameters>
        <customMessage>Avoid using Object.toStringHelper. Use ToStringBuilder instead.</customMessage>
    </check>

    <check customId="runtimeaddshutdownhook" level="error" class="org.scalastyle.file.RegexChecker" enabled="true">
        <parameters><parameter name="regex">Runtime\.getRuntime\.addShutdownHook</parameter></parameters>
        <customMessage><![CDATA[
      Are you sure that you want to use Runtime.getRuntime.addShutdownHook? In most cases, you should use
      ShutdownHookManager.addShutdownHook instead.
      If you must use Runtime.getRuntime.addShutdownHook, wrap the code block with
      // scalastyle:off runtimeaddshutdownhook
      Runtime.getRuntime.addShutdownHook(...)
      // scalastyle:on runtimeaddshutdownhook
    ]]></customMessage>
    </check>

    <check customId="mutablesynchronizedbuffer" level="error" class="org.scalastyle.file.RegexChecker" enabled="true">
        <parameters>
            <parameter name="regex">mutable\.SynchronizedBuffer</parameter>
        </parameters>
        <customMessage><![CDATA[
          Are you sure that you want to use mutable.SynchronizedBuffer? In most cases, you should use
          java.util.concurrent.ConcurrentLinkedQueue instead.
          If you must use mutable.SynchronizedBuffer, wrap the code block with
          // scalastyle:off mutablesynchronizedbuffer
          mutable.SynchronizedBuffer[...]
          // scalastyle:on mutablesynchronizedbuffer
        ]]>
        </customMessage>
    </check>

    <check customId="println" level="error" class="org.scalastyle.scalariform.TokenChecker" enabled="true">
        <parameters><parameter name="regex">^println$</parameter></parameters>
        <customMessage><![CDATA[Are you sure you want to println? If yes, wrap the code block with
      // scalastyle:off println
      println(...)
      // scalastyle:on println]]></customMessage>
    </check>

    <check customId="awaitresult" level="error" class="org.scalastyle.file.RegexChecker" enabled="true">
        <parameters>
            <parameter name="regex">Await\.result</parameter>
        </parameters>
        <customMessage><![CDATA[
          Are you sure that you want to use Await.result? In most cases, you should use ThreadUtils.awaitResult instead.
          If you must use Await.result, wrap the code block with
          // scalastyle:off awaitresult
          Await.result(...)
          // scalastyle:on awaitresult
        ]]>
        </customMessage>
    </check>

    <check customId="commons-lang2" level="error" class="org.scalastyle.scalariform.TokenChecker" enabled="true">
        <parameters>
            <parameter name="regex">org\.apache\.commons\.lang\.</parameter>
        </parameters>
        <customMessage>Use Commons Lang 3 classes (package org.apache.commons.lang3.*) instead
            of Commons Lang 2 (package org.apache.commons.lang.*)
        </customMessage>
    </check>

    <!-- Doesn't seem super big deal here ... -->
    <check level="error" class="org.scalastyle.file.FileLengthChecker" enabled="true">
        <parameters>
            <parameter name="maxFileLength">800</parameter>
        </parameters>
    </check>

    <!-- Doesn't seem super big deal here ... -->
    <check level="error" class="org.scalastyle.scalariform.NumberOfTypesChecker" enabled="true">
        <parameters>
            <parameter name="maxTypes">50</parameter>
        </parameters>
    </check>

    <!-- Doesn't seem super big deal here ... -->
    <check level="error" class="org.scalastyle.scalariform.CyclomaticComplexityChecker" enabled="true">
        <parameters>
            <parameter name="maximum">80</parameter>
        </parameters>
    </check>

    <!--    <check level="error" class="org.scalastyle.scalariform.PublicMethodsHaveTypeChecker" enabled="true"/>-->
    <check level="error" class="org.scalastyle.file.NewLineAtEofChecker" enabled="true"/>

    <!-- Avoid Java annotations -->
    <check level="error" class="org.scalastyle.scalariform.OverrideJavaChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.DeprecatedJavaChecker" enabled="true"/>

    <check level="error" class="org.scalastyle.scalariform.EnsureSingleSpaceBeforeTokenChecker" enabled="true">
        <parameters>
            <parameter name="tokens">ARROW, EQUALS, ELSE, TRY, CATCH, FINALLY, LARROW, RARROW</parameter>
        </parameters>
    </check>

    <check level="error" class="org.scalastyle.scalariform.EnsureSingleSpaceAfterTokenChecker" enabled="true">
        <parameters>
            <parameter name="tokens">ARROW, EQUALS, COMMA, COLON, IF, ELSE, DO, WHILE, FOR, MATCH, TRY, CATCH, FINALLY, LARROW, RARROW
            </parameter>
        </parameters>
    </check>

    <check level="error" class="org.scalastyle.scalariform.DisallowSpaceBeforeTokenChecker" enabled="true">
        <parameters>
            <parameter name="tokens">COMMA</parameter>
        </parameters>
    </check>

    <!-- ??? usually shouldn't be checked into the code base. -->
    <check level="error" class="org.scalastyle.scalariform.NotImplementedErrorUsage" enabled="true"/>


    <!-- ================================================================================ -->
    <!--                               rules we don't want                                -->
    <!-- ================================================================================ -->
    <check customId="javaconversions" level="error" class="org.scalastyle.scalariform.TokenChecker" enabled="false">
        <parameters><parameter name="regex">JavaConversions</parameter></parameters>
        <customMessage>Instead of importing implicits in scala.collection.JavaConversions._, import
            scala.collection.JavaConverters._ and use .asScala / .asJava methods</customMessage>
    </check>

    <!-- Do not enable ScalaDocChecker below. This forces all the classes,-->
    <!-- traits, methods, types and properties to have documentation which-->
    <!-- is overwhelming.-->
    <check level="error" class="org.scalastyle.scalariform.ScalaDocChecker" enabled="false"/>

    <!-- This one complains about all kinds of random things. Disable. -->
    <check level="error" class="org.scalastyle.scalariform.SimplifyBooleanExpressionChecker" enabled="false"/>

    <!-- We want the opposite of this: NewLineAtEofChecker is enabled above -->
    <check level="error" class="org.scalastyle.file.NoNewLineAtEofChecker" enabled="false"/>

    <!-- This breaks symbolic method names so we don't turn it on. -->
    <!-- Maybe we should update it to allow basic symbolic names, and then we are good to go. -->
    <check level="error" class="org.scalastyle.scalariform.MethodNamesChecker" enabled="false">
        <parameters>
            <parameter name="regex"><![CDATA[^[a-z][A-Za-z0-9]*$]]></parameter>
        </parameters>
    </check>

</scalastyle>