Unused variable not detected

[rafaelaguerra]

SonarLint is detecting unused local variable locally, but detekt doesn't. Is it normal? Should detekt has more or less the same rules of sonarLint or sonar-kotlin(from sonar)?

Code:

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val a : TextView? = null

}

And here is my detekt config file:

processors:
  active: true
  exclude:
  # - 'FunctionCountProcessor'
  # - 'PropertyCountProcessor'
  # - 'ClassCountProcessor'
  # - 'PackageCountProcessor'
  # - 'KtFileCountProcessor'

console-reports:
  active: true
  exclude:
  #  - 'ProjectStatisticsReport'
  #  - 'ComplexityReport'
  #  - 'NotificationReport'
  #  - 'FindingsReport'
  #  - 'BuildFailureReport'

comments:
  active: true
  excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
  CommentOverPrivateFunction:
    active: false
  CommentOverPrivateProperty:
    active: false
  EndOfSentenceFormat:
    active: false
    endOfSentenceFormat: ([.?!][ \t\n\r\f<])|([.?!:]$)
  UndocumentedPublicClass:
    active: false
    searchInNestedClass: true
    searchInInnerClass: true
    searchInInnerObject: true
    searchInInnerInterface: true
  UndocumentedPublicFunction:
    active: false

complexity:
  active: true
  ComplexCondition:
    active: true
    threshold: 4
  ComplexInterface:
    active: false
    threshold: 10
    includeStaticDeclarations: false
  ComplexMethod:
    active: true
    threshold: 10
    ignoreSingleWhenExpression: false
    ignoreSimpleWhenEntries: false
  LabeledExpression:
    active: true
    ignoredLabels: ""
  LargeClass:
    active: true
    threshold: 600
  LongMethod:
    active: true
    threshold: 60
  LongParameterList:
    active: true
    threshold: 6
    ignoreDefaultParameters: false
  MethodOverloading:
    active: true
    threshold: 6
  NestedBlockDepth:
    active: true
    threshold: 4
  StringLiteralDuplication:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    threshold: 3
    ignoreAnnotation: true
    excludeStringsWithLessThan5Characters: true
    ignoreStringsRegex: '$^'
  TooManyFunctions:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    thresholdInFiles: 11
    thresholdInClasses: 11
    thresholdInInterfaces: 11
    thresholdInObjects: 11
    thresholdInEnums: 11
    ignoreDeprecated: false
    ignorePrivate: false
    ignoreOverridden: false

empty-blocks:
  active: true
  EmptyCatchBlock:
    active: true
    allowedExceptionNameRegex: "^(_|(ignore|expected).*)"
  EmptyClassBlock:
    active: true
  EmptyDefaultConstructor:
    active: true
  EmptyDoWhileBlock:
    active: true
  EmptyElseBlock:
    active: true
  EmptyFinallyBlock:
    active: true
  EmptyForBlock:
    active: true
  EmptyFunctionBlock:
    active: true
    ignoreOverriddenFunctions: false
  EmptyIfBlock:
    active: true
  EmptyInitBlock:
    active: true
  EmptyKtFile:
    active: true
  EmptySecondaryConstructor:
    active: true
  EmptyWhenBlock:
    active: true
  EmptyWhileBlock:
    active: true

exceptions:
  active: true
  ExceptionRaisedInUnexpectedLocation:
    active: true
    methodNames: 'toString,hashCode,equals,finalize'
  InstanceOfCheckForException:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
  NotImplementedDeclaration:
    active: true
  PrintStackTrace:
    active: true
  RethrowCaughtException:
    active: true
  ReturnFromFinally:
    active: true
  SwallowedException:
    active: true
    ignoredExceptionTypes: 'InterruptedException,NumberFormatException,ParseException,MalformedURLException'
    allowedExceptionNameRegex: "^(_|(ignore|expected).*)"
  ThrowingExceptionFromFinally:
    active: true
  ThrowingExceptionInMain:
    active: true
  ThrowingExceptionsWithoutMessageOrCause:
    active: true
    exceptions: 'IllegalArgumentException,IllegalStateException,IOException'
  ThrowingNewInstanceOfSameException:
    active: true
  TooGenericExceptionCaught:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    exceptionNames:
      - ArrayIndexOutOfBoundsException
      - Error
      - Exception
      - IllegalMonitorStateException
      - NullPointerException
      - IndexOutOfBoundsException
      - RuntimeException
      - Throwable
    allowedExceptionNameRegex: "^(_|(ignore|expected).*)"
  TooGenericExceptionThrown:
    active: true
    exceptionNames:
      - Error
      - Exception
      - Throwable
      - RuntimeException

formatting:
  active: true
  android: false
  autoCorrect: true
  AnnotationOnSeparateLine:
    active: true
    autoCorrect: true
  ChainWrapping:
    active: true
    autoCorrect: true
  CommentSpacing:
    active: false
  Filename:
    active: true
  FinalNewline:
    active: true
    autoCorrect: true
  ImportOrdering:
    active: false
    autoCorrect: true
  Indentation:
    active: true
    autoCorrect: true
    indentSize: 4
    continuationIndentSize: 4
  MaximumLineLength:
    active: true
    maxLineLength: 120
  ModifierOrdering:
    active: true
    autoCorrect: true
  MultiLineIfElse:
    active: true
    autoCorrect: true
  NoBlankLineBeforeRbrace:
    active: true
    autoCorrect: true
  NoConsecutiveBlankLines:
    active: true
    autoCorrect: true
  NoEmptyClassBody:
    active: true
    autoCorrect: true
  NoLineBreakAfterElse:
    active: true
    autoCorrect: true
  NoLineBreakBeforeAssignment:
    active: true
    autoCorrect: true
  NoMultipleSpaces:
    active: true
    autoCorrect: true
  NoSemicolons:
    active: true
    autoCorrect: true
  NoTrailingSpaces:
    active: true
    autoCorrect: true
  NoUnitReturn:
    active: true
    autoCorrect: true
  NoUnusedImports:
    active: true
    autoCorrect: true
  NoWildcardImports:
    active: true
  PackageName:
    active: true
    autoCorrect: true
  ParameterListWrapping:
    active: true
    autoCorrect: true
    indentSize: 4
  SpacingAroundColon:
    active: true
    autoCorrect: true
  SpacingAroundComma:
    active: true
    autoCorrect: true
  SpacingAroundCurly:
    active: true
    autoCorrect: true
  SpacingAroundDot:
    active: true
    autoCorrect: true
  SpacingAroundKeyword:
    active: true
    autoCorrect: true
  SpacingAroundOperators:
    active: true
    autoCorrect: true
  SpacingAroundParens:
    active: true
    autoCorrect: true
  SpacingAroundRangeOperator:
    active: true
    autoCorrect: true
  StringTemplate:
    active: true
    autoCorrect: true

naming:
  active: true
  ClassNaming:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    classPattern: '[A-Z$][a-zA-Z0-9$]*'
  ConstructorParameterNaming:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    parameterPattern: '[a-z][A-Za-z0-9]*'
    privateParameterPattern: '[a-z][A-Za-z0-9]*'
    excludeClassPattern: '$^'
  EnumNaming:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    enumEntryPattern: '^[A-Z][_a-zA-Z0-9]*'
  ForbiddenClassName:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    forbiddenName: ''
  FunctionMaxLength:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    maximumFunctionNameLength: 30
  FunctionMinLength:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    minimumFunctionNameLength: 3
  FunctionNaming:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    functionPattern: '^([a-z$][a-zA-Z$0-9]*)|(`.*`)$'
    excludeClassPattern: '$^'
    ignoreOverridden: true
  FunctionParameterNaming:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    parameterPattern: '[a-z][A-Za-z0-9]*'
    excludeClassPattern: '$^'
    ignoreOverriddenFunctions: true
  InvalidPackageDeclaration:
    active: true
    rootPackage: ''
  MatchingDeclarationName:
    active: true
  MemberNameEqualsClassName:
    active: true
    ignoreOverriddenFunction: true
  ObjectPropertyNaming:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    constantPattern: '[A-Za-z][_A-Za-z0-9]*'
    propertyPattern: '[A-Za-z][_A-Za-z0-9]*'
    privatePropertyPattern: '(_)?[A-Za-z][_A-Za-z0-9]*'
  PackageNaming:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    packagePattern: '^[a-z]+(\.[a-z][A-Za-z0-9]*)*$'
  TopLevelPropertyNaming:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    constantPattern: '[A-Z][_A-Z0-9]*'
    propertyPattern: '[A-Za-z][_A-Za-z0-9]*'
    privatePropertyPattern: '_?[A-Za-z][_A-Za-z0-9]*'
  VariableMaxLength:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    maximumVariableNameLength: 64
  VariableMinLength:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    minimumVariableNameLength: 1
  VariableNaming:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    variablePattern: '[a-z][A-Za-z0-9]*'
    privateVariablePattern: '(_)?[a-z][A-Za-z0-9]*'
    excludeClassPattern: '$^'
    ignoreOverridden: true

performance:
  active: true
  ArrayPrimitive:
    active: true
  ForEachOnRange:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
  SpreadOperator:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
  UnnecessaryTemporaryInstantiation:
    active: true

potential-bugs:
  active: true
  DuplicateCaseInWhenExpression:
    active: true
  EqualsAlwaysReturnsTrueOrFalse:
    active: true
  EqualsWithHashCodeExist:
    active: true
  ExplicitGarbageCollectionCall:
    active: true
  InvalidRange:
    active: true
  IteratorHasNextCallsNextMethod:
    active: true
  IteratorNotThrowingNoSuchElementException:
    active: true
  LateinitUsage:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    excludeAnnotatedProperties: ""
    ignoreOnClassesPattern: ""
  MissingWhenCase:
    active: true
  RedundantElseInWhen:
    active: true
  UnconditionalJumpStatementInLoop:
    active: true
  UnreachableCode:
    active: true
  UnsafeCallOnNullableType:
    active: true
  UnsafeCast:
    active: true
  UselessPostfixExpression:
    active: true
  WrongEqualsTypeParameter:
    active: true

style:
  active: true
  CollapsibleIfStatements:
    active: true
  DataClassContainsFunctions:
    active: true
    conversionFunctionPrefix: 'to'
  DataClassShouldBeImmutable:
    active: true
  EqualsNullCall:
    active: true
  EqualsOnSignatureLine:
    active: true
  ExplicitItLambdaParameter:
    active: true
  ExpressionBodySyntax:
    active: true
    includeLineWrapping: false
  ForbiddenComment:
    active: true
    values: 'TODO:,FIXME:,STOPSHIP:'
  ForbiddenImport:
    active: true
    imports: ''
  ForbiddenVoid:
    active: true
    ignoreOverridden: false
    ignoreUsageInGenerics: false
  FunctionOnlyReturningConstant:
    active: true
    ignoreOverridableFunction: true
    excludedFunctions: 'describeContents'
  LibraryCodeMustSpecifyReturnType:
    active: true
  LoopWithTooManyJumpStatements:
    active: true
    maxJumpCount: 1
  MagicNumber:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    ignoreNumbers: '-1,0,1,2'
    ignoreHashCodeFunction: true
    ignorePropertyDeclaration: false
    ignoreConstantDeclaration: true
    ignoreCompanionObjectPropertyDeclaration: true
    ignoreAnnotation: false
    ignoreNamedArgument: true
    ignoreEnums: false
    ignoreRanges: false
  MandatoryBracesIfStatements:
    active: true
  MaxLineLength:
    active: true
    maxLineLength: 120
    excludePackageStatements: true
    excludeImportStatements: true
    excludeCommentStatements: false
  MayBeConst:
    active: true
  ModifierOrder:
    active: true
  NestedClassesVisibility:
    active: true
  NewLineAtEndOfFile:
    active: false
  NoTabs:
    active: true
  OptionalAbstractKeyword:
    active: true
  OptionalUnit:
    active: true
  OptionalWhenBraces:
    active: true
  PreferToOverPairSyntax:
    active: true
  ProtectedMemberInFinalClass:
    active: true
  RedundantVisibilityModifierRule:
    active: true
  ReturnCount:
    active: true
    max: 2
    excludedFunctions: "equals"
    excludeLabeled: false
    excludeReturnFromLambda: true
  SafeCast:
    active: true
  SerialVersionUIDInSerializableClass:
    active: true
  SpacingBetweenPackageAndImports:
    active: true
  ThrowsCount:
    active: true
    max: 2
  TrailingWhitespace:
    active: true
  UnderscoresInNumericLiterals:
    active: true
    acceptableDecimalLength: 5
  UnnecessaryAbstractClass:
    active: true
    excludeAnnotatedClasses: "dagger.Module"
  UnnecessaryApply:
    active: true
  UnnecessaryInheritance:
    active: true
  UnnecessaryLet:
    active: true
  UnnecessaryParentheses:
    active: true
  UntilInsteadOfRangeTo:
    active: true
  UnusedImports:
    active: true
  UnusedPrivateClass:
    active: true
  UnusedPrivateMember:
    active: true
    allowedNames: "(_|ignored|expected|serialVersionUID)"
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
  UseCheckOrError:
    active: true
  UseDataClass:
    active: true
    excludeAnnotatedClasses: ""
  UseRequire:
    active: true
  UselessCallOnNotNull:
    active: true
  UtilityClassWithPublicConstructor:
    active: true
  VarCouldBeVal:
    active: true
  WildcardImport:
    active: true
    excludes: "**/test/**,**/androidTest/**,**/*.Test.kt,**/*.Spec.kt,**/*.Spek.kt"
    excludeImports: 'java.util.*,kotlinx.android.synthetic.*'

[rafaelaguerra]

If I use the official sonar-kotlin plugin from https://docs.sonarqube.org/latest/analysis/languages/kotlin/ and apply sonar.kotlin.detekt.reportPaths, detekts reports unused variable as critical, and sonar rules as minor. Any idea why?

[rafaelaguerra]

Ok solved.

1. Apply detekt plugin in sonarqube
2. Sonarqube > Quality profile > kotlin > apply detekt all as default
3. Setup sonar.kotlin.detekt.reportPaths=build/reports/detekt/detekt.xml into sonar-project.properties
4. gradle

   detekt {
   config = files("$rootDir/default-detekt-config.yml")
   }

For me it stills a little strange why for sonarLint this is minor, and detekt is critical.