Codenarc Revisited - Gr8Conf US 2016

Codenarc Revisited
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When was the last time you looked at code quality? Do you have some old codenarc configuration with half(or more!) of the rules turned off because they were reporting false positives? Or maybe you have @SupressWarnings all over your code? Or perhaps you want to do something small like to enforce tabs vs spaces for all members of your team?

Codenarc is a static analysis tool for Groovy that enforces style, detects bad practices, and suggests improvements. If it has been awhile since you last looked at codenarc, there might be new rules or configuration options to get you back on the path to better code quality. This session will explore what is new with codenarc, options for specific groovy ecosystem projects such as grails, and walk through how to create custom rules for your own project.
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Jennifer “Jenn” Strater is a software engineer with a passion for developing and designing applications using new and innovative technologies. Her strengths are in the service layer including building RESTful APIs. Jenn also has experience with relational and NoSQL databases, devops, front-end, and mobile in the healthcare and transportation industries. She learns new tools and systems quickly and introduces new technology learned through local community groups, involvement in the international Groovy community, and when speaking at or attending regional, national, and international conferences.

Jenn is the co-founder of the organization Gr8Ladies and has organized Gr8Workshops for developers interested in an overview and crash course in Groovy technologies. She has presented at various Minnesota tech events, the Grace Hopper Celebration of Women in Computing, Greach, Gr8Conf EU, Gr8Conf US, and Devoxx Belgium.

Starting in September, Jenn will be a master's student at the Technical University of Denmark studying static analysis and compilers with a focus on Groovy with funding from the Fulbright U.S. student program.

Transcript

1. Codenarc Revisited
   Jenn Strater
   @codeJENNerator
   

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2. @codeJENNerator
   Follow Along
   • https://github.com/jlstrater/gr8data/tree/master/config/codenarc
   • https://github.com/jlstrater/groovy-spring-boot-restdocs-
   example/tree/master/gradle/codenarc
   

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3. @codeJENNerator
   About Me
   

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4. @codeJENNerator
   About Me
   • Senior Consultant at Object Partners, Inc.
   

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5. @codeJENNerator
   About Me
   • Senior Consultant at Object Partners, Inc.
   • Co-Founder of Gr8Ladies
   

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6. @codeJENNerator
   About Me
   • Senior Consultant at Object Partners, Inc.
   • Co-Founder of Gr8Ladies
   • 2016 - 2017 Fulbright US Student Program Selectee
   to Denmark
   

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7. @codeJENNerator
   Background
   

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8. @codeJENNerator
   Background
   • Spring Boot with Groovy
   

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9. @codeJENNerator
   Background
   • Spring Boot with Groovy
   • Ratpack with Groovy
   

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10. @codeJENNerator
    Background
    • Spring Boot with Groovy
    • Ratpack with Groovy
    • Grails
    

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11. @codeJENNerator
    Background
    • Spring Boot with Groovy
    • Ratpack with Groovy
    • Grails
    • Anything Else?
    

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12. @codeJENNerator
    What is ?
    

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13. @codeJENNerator
    https://github.com/CodeNarc/CodeNarc
    “CodeNarc is a static analysis tool for Groovy
    source code, enabling monitoring and
    enforcement of many coding standards and best
    practices…
    CodeNarc is similar to popular static analysis
    tools such as PMD or Checkstyle. Unlike those
    tools which analyze Java code, CodeNarc
    analyzes Groovy code.”
    

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14. @codeJENNerator
    

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15. @codeJENNerator
    • Website
    • codenarc.sourceforge.net
    

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16. @codeJENNerator
    • Website
    • codenarc.sourceforge.net
    • Current Version
    • 0.25.2
    

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17. @codeJENNerator
    

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18. @codeJENNerator
    • Mailing List
    • https://sourceforge.net/p/codenarc/mailman
    

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19. @codeJENNerator
    • Mailing List
    • https://sourceforge.net/p/codenarc/mailman
    • Project Admin
    • Chris Mair
    

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20. @codeJENNerator
    Why use Codenarc?
    • Improves readability
    • Saves time with code reviews
    • Code with fewer bugs
    • Help onboard new team members
    

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22. @codeJENNerator
    .equals instead of ==
    

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24. @codeJENNerator
    

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25. @codeJENNerator
    def someMethod(def something, def somethingElse) {

    if (something) {

    doSomething()

    }

    else if(somethingElse) {

    doSomethingElse()

    }

    }
    

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26. @codeJENNerator
    def someMethod(def something, def somethingElse) {

    if (something) {

    doSomething()

    }

    else if(somethingElse) {

    doSomethingElse()

    }

    }
    

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27. @codeJENNerator
    def someMethod(def something, def somethingElse) {

    if (something) {

    doSomething()

    }

    else if(somethingElse) {

    doSomethingElse()

    }

    }
    

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28. @codeJENNerator
    The Convert
    

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29. @codeJENNerator
    

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30. @codeJENNerator
    println “This is an unnecessary Groovy String”

    

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31. @codeJENNerator
    

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32. @codeJENNerator
    this.something.getThisThing()
    

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33. @codeJENNerator
    New Team Member
    

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34. @codeJENNerator
    if(true) { }
    vs
    if (true) { }
    vs
    if (ready){ }
    

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35. @codeJENNerator
    Leaning Tower of Code
    https://flic.kr/p/de4pmb
    

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36. @codeJENNerator
    Summary
    • Useful For:
    • Interns/Junior Devs
    • Java Devs converting to Groovy
    • New Team Members
    • YOU!
    

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37. @codeJENNerator
    Approaches
    

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38. @codeJENNerator
    Approaches
    • Start with one project or team
    

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39. @codeJENNerator
    Approaches
    • Start with one project or team
    • Turn on all rules
    

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40. @codeJENNerator
    Approaches
    • Start with one project or team
    • Turn on all rules
    • Look at all of the violations
    

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41. @codeJENNerator
    Approaches
    • Start with one project or team
    • Turn on all rules
    • Look at all of the violations
    • Turn off rules that don’t make sense for your team
    

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42. @codeJENNerator
    Approaches
    • Start with one project or team
    • Turn on all rules
    • Look at all of the violations
    • Turn off rules that don’t make sense for your team
    • Fix all the problems
    

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43. @codeJENNerator
    Approaches
    • Start with one project or team
    • Turn on all rules
    • Look at all of the violations
    • Turn off rules that don’t make sense for your team
    • Fix all the problems
    • Once you have a good set of rules with minimal false
    positives, set that as the standard for all teams using
    Groovy
    

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45. @codeJENNerator
    Approaches
    • Turn on all the rules
    • Set a violation limit and fail builds that add go
    above the limit
    

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46. @codeJENNerator
    Basics
    https://flic.kr/p/oiAEx6
    

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47. @codeJENNerator
    What is a rule?
    

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48. @codeJENNerator
    What is a rule?
    MissingBlankLineAfterPackage
    

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49. @codeJENNerator
    What is a rule?
    MissingBlankLineAfterPackage
    package org.codenarc

    import java.util.Date // violation

    

    class MyClass {

    void go() { /* ... */ }

    }
    

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50. @codeJENNerator
    What is a ruleset?
    

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51. @codeJENNerator
    What is a ruleset?
    Formatting Rules ("rulesets/formatting.xml")
    

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52. @codeJENNerator
    Rule Configuration
    

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53. @codeJENNerator
    Rule Configuration
    • Priority
    

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54. @codeJENNerator
    Rule Configuration
    • Priority
    • ViolationMessage
    

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55. @codeJENNerator
    Rule Configuration
    • Priority
    • ViolationMessage
    • Description
    

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56. @codeJENNerator
    Rule Configuration
    • Priority
    • ViolationMessage
    • Description
    • Name
    

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57. @codeJENNerator
    Rule Configuration
    

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58. @codeJENNerator
    Rule Configuration
    • Custom Parameters
    

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59. @codeJENNerator
    Rule Configuration
    • Custom Parameters
    • applyToClassNames
    

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60. @codeJENNerator
    Rule Configuration
    • Custom Parameters
    • applyToClassNames
    • applyToFileNames
    

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61. @codeJENNerator
    Ways to add codenarc
    to your project
    

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62. @codeJENNerator
    • runs with gradle check
    https://docs.gradle.org/current/userguide/codenarc_plugin.html
    

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63. @codeJENNerator
    Config Options
    

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64. @codeJENNerator
    Config Options
    • configFile
    • ignoreFailures
    • maxPriority1Violations
    • maxPriority2Violations
    • maxPriority3Violations
    

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65. @codeJENNerator
    Config Options
    

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66. @codeJENNerator
    Config Options
    • reportFormat
    • reportsDir
    • sourceSets
    • toolVersion
    

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67. @codeJENNerator
    

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68. @codeJENNerator
    codenarc {

    toolVersion = '0.25.2'

    }

    

    codenarcMain {

    configFile file('config/codenarc/codenarc.groovy')

    }

    

    codenarcTest {

    configFile file('config/codenarc/codenarcTest.groovy')

    }
    

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69. @codeJENNerator
    • Grails Projects Version < 3.0
    • runs with grails codenarc
    http://grails.org/plugin/codenarc
    Plugin
    

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70. @codeJENNerator
    Other Codenarc Plugins
    

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71. @codeJENNerator
    Other Codenarc Plugins
    • IDEs
    • IntelliJ
    • Eclipse
    

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72. @codeJENNerator
    Other Codenarc Plugins
    • IDEs
    • IntelliJ
    • Eclipse
    • Sonar
    

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73. @codeJENNerator
    Other Codenarc Plugins
    • IDEs
    • IntelliJ
    • Eclipse
    • Sonar
    • Maven
    

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74. @codeJENNerator
    Other Codenarc Plugins
    • IDEs
    • IntelliJ
    • Eclipse
    • Sonar
    • Maven
    • Jenkins (formerly Hudson)
    

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75. @codeJENNerator
    Reports
    

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76. @codeJENNerator
    build/reports/codenarc/main.html
    

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77. @codeJENNerator
    Jenkins Violations Plugin
    img src: https://leanjavaengineering.wordpress.com/2010/08/25/grails-codenarc-hudson/
    

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78. @codeJENNerator
    Starter Ruleset
    http://codenarc.sourceforge.net/StarterRuleSet-
    AllRulesByCategory.groovy.txt
    https://flic.kr/p/c8QjRC
    

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79. @codeJENNerator
    config/codenarc/codenarc.groovy
    ruleset {

    // rulesets/basic.xml

    AssertWithinFinallyBlock

    AssignmentInConditional

    BigDecimalInstantiation

    BitwiseOperatorInConditional

    BooleanGetBoolean

    BrokenNullCheck

    BrokenOddnessCheck

    ClassForName

    ComparisonOfTwoConstants

    ComparisonWithSelf

    ConstantAssertExpression

    ConstantIfExpression

    ConstantTernaryExpression

    .
    .
    .
    // rulesets/braces.xml

    ElseBlockBraces(bracesRequiredForElseIf: true)

    ForStatementBraces

    IfStatementBraces

    WhileStatementBraces
    .
    .
    .
    }
    

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80. @codeJENNerator
    Turning Off Rules - Comments
    ruleset {
    /*
    // rulesets/braces.xml

    ElseBlockBraces(bracesRequiredForElseIf: true)

    ForStatementBraces

    IfStatementBraces

    WhileStatementBraces
    */
    }
    

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81. @codeJENNerator
    Turning Off Rules -
    Enabled:False
    ruleset {
    ruleset('rulesets/basic.xml') {
    CatchThrowable(enabled:false)
    }
    }
    

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82. @codeJENNerator
    Suppress Warnings
    

    

    @SuppressWarnings('DuplicateStringLiteral')

    class MyClass {

    def y = 'x'

    def z = 'x'

    

    @SuppressWarnings(['IfStatementBraces', 'ThrowException'])

    int getCount() {

    if (!ready) throw new Exception('Not ready')

    }

    }
    

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83. https://flic.kr/p/rmit9T
    

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84. @codeJENNerator
    0.21
    • No Wildcard Imports
    • Lots of New Formatting Rules
    • Consecutive Blank Lines
    • Blank Line Before Package
    • FileEndsWithoutNewline
    

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85. @codeJENNerator
    0.22
    • No Def
    • Unnecessary Safe Navigation Operator
    

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86. @codeJENNerator
    0.23
    • Nested For Loop
    

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87. @codeJENNerator
    0.25
    • No Tab Character
    • Trailing Comma
    

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88. @codeJENNerator
    Each Release Improves Existing Rules
    https://flic.kr/p/3mPXcD
    

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89. @codeJENNerator
    Rules Worth Talking
    About
    

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90. @codeJENNerator
    File Ends Without
    NewLine
    

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91. @codeJENNerator
    I don’t like all of the Codenarc Rules!
    img src: https://flic.kr/p/rehEf5
    

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92. @codeJENNerator
    Dry
    • DuplicateListLiteral
    • DuplicateMapLiteral
    • DuplicateNumberLiteral
    • DuplicateStringLiteral
    

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93. @codeJENNerator
    Could Be Elvis
    Lots of false positives
    

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94. @codeJENNerator
    JUnit Ruleset
    Doesn’t work well with Spock
    

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95. @codeJENNerator
    No Def
    https://flic.kr/p/apRkJh
    

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96. @codeJENNerator
    No Def
    • Great for Spring Boot
    https://flic.kr/p/apRkJh
    

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97. @codeJENNerator
    No Def
    • Great for Spring Boot
    • Problematic with Grails
    https://flic.kr/p/apRkJh
    

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98. @codeJENNerator
    Good in Theory
    

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99. @codeJENNerator
    Good in Theory
    • Unnecessary Return
    

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100. @codeJENNerator
     Good in Theory
     • Unnecessary Return
     • Line Length
     

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101. @codeJENNerator
     Debatable
     

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102. @codeJENNerator
     Debatable
     • Unnecessary Groovy String
     

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103. @codeJENNerator
     Debatable
     • Unnecessary Groovy String
     • Unnecessary Getter
     

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104. @codeJENNerator
     Debatable
     

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105. @codeJENNerator
     Debatable
     • Misordered Static Imports
     

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106. @codeJENNerator
     Debatable
     • Misordered Static Imports
     • No Wildcard Imports
     

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107. @codeJENNerator
     Still Deciding
     

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108. @codeJENNerator
     Still Deciding
     • Complexity Metrics
     

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109. @codeJENNerator
     WARNING!
     • Enhanced Ruleset does not work with the gradle
     codenarc plugin
     • https://objectpartners.com/2016/03/16/resolving-
     codenarc-compilation-warnings/
     

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110. @codeJENNerator
     Create a Custom Rule
     import org.codenarc.rule.AbstractRule

     import org.codenarc.source.SourceCode

     

     /**

     * Sample rule. Checks for static fields.

     */

     class MyStaticFieldRule extends AbstractRule {

     String name = 'MyStaticField'

     int priority = 2

     

     void applyTo(SourceCode sourceCode, List violations) {

     sourceCode.ast.classes.each { clazz ->

     clazz.fields.each { fieldNode ->

     if (fieldNode.static) {

     violations << createViolation(sourceCode, fieldNode)

     }

     }

     }

     }

     }
     

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111. @codeJENNerator
     Contribute
     • http://codenarc.sourceforge.net/codenarc-
     developer-guide.html
     • https://github.com/CodeNarc/CodeNarc
     

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112. @codeJENNerator
     Read the docs for more on..
     • Rule Specifics
     • Ant Task
     • Command Line
     

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113. @codeJENNerator
     Example Rulesets
     • Grails
     • https://github.com/jlstrater/gr8data/tree/master/
     config/codenarc
     • Spring Boot
     • https://github.com/jlstrater/groovy-spring-boot-
     restdocs-example/tree/master/gradle/codenarc
     

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114. @codeJENNerator
     Conclusion
     

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115. @codeJENNerator
     Questions?
     https://flic.kr/p/5DeuzB
     

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