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
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
3. @codeJENNerator About Me
4. @codeJENNerator About Me • Senior Consultant at Object Partners, Inc.
5. @codeJENNerator About Me • Senior Consultant at Object Partners, Inc. • Co-Founder of Gr8Ladies
6. @codeJENNerator About Me • Senior Consultant at Object Partners, Inc. • Co-Founder of Gr8Ladies • 2016 - 2017 Fulbright US Student Program Selectee to Denmark
7. @codeJENNerator Background
8. @codeJENNerator Background • Spring Boot with Groovy
9. @codeJENNerator Background • Spring Boot with Groovy • Ratpack with Groovy
10. @codeJENNerator Background • Spring Boot with Groovy • Ratpack with Groovy • Grails
11. @codeJENNerator Background • Spring Boot with Groovy • Ratpack with Groovy • Grails • Anything Else?
12. @codeJENNerator What is ?
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.”
14. @codeJENNerator
15. @codeJENNerator • Website • codenarc.sourceforge.net
16. @codeJENNerator • Website • codenarc.sourceforge.net • Current Version • 0.25.2
17. @codeJENNerator
18. @codeJENNerator • Mailing List • https://sourceforge.net/p/codenarc/mailman
19. @codeJENNerator • Mailing List • https://sourceforge.net/p/codenarc/mailman • Project Admin • Chris Mair
20. @codeJENNerator Why use Codenarc? • Improves readability • Saves time with code reviews • Code with fewer bugs • Help onboard new team members
22. @codeJENNerator .equals instead of ==
24. @codeJENNerator
25. @codeJENNerator def someMethod(def something, def somethingElse) {
 if (something) {
 doSomething()
 }
 else if(somethingElse) {
 doSomethingElse()
 }
 }
26. @codeJENNerator def someMethod(def something, def somethingElse) {
 if (something) {
 doSomething()
 }
 else if(somethingElse) {
 doSomethingElse()
 }
 }
27. @codeJENNerator def someMethod(def something, def somethingElse) {
 if (something) {
 doSomething()
 }
 else if(somethingElse) {
 doSomethingElse()
 }
 }
28. @codeJENNerator The Convert
29. @codeJENNerator
30. @codeJENNerator println “This is an unnecessary Groovy String”

31. @codeJENNerator
32. @codeJENNerator this.something.getThisThing()
33. @codeJENNerator New Team Member
34. @codeJENNerator if(true) { } vs if (true) { } vs if (ready){ }
35. @codeJENNerator Leaning Tower of Code https://flic.kr/p/de4pmb
36. @codeJENNerator Summary • Useful For: • Interns/Junior Devs • Java Devs converting to Groovy • New Team Members • YOU!
37. @codeJENNerator Approaches
38. @codeJENNerator Approaches • Start with one project or team
39. @codeJENNerator Approaches • Start with one project or team • Turn on all rules
40. @codeJENNerator Approaches • Start with one project or team • Turn on all rules • Look at all of the violations
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
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
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
45. @codeJENNerator Approaches • Turn on all the rules • Set a violation limit and fail builds that add go above the limit
46. @codeJENNerator Basics https://flic.kr/p/oiAEx6
47. @codeJENNerator What is a rule?
48. @codeJENNerator What is a rule? MissingBlankLineAfterPackage
49. @codeJENNerator What is a rule? MissingBlankLineAfterPackage package org.codenarc
 import java.util.Date // violation
 
 class MyClass {
 void go() { /* ... */ }
 }
50. @codeJENNerator What is a ruleset?
51. @codeJENNerator What is a ruleset? Formatting Rules ("rulesets/formatting.xml")
52. @codeJENNerator Rule Configuration
53. @codeJENNerator Rule Configuration • Priority
54. @codeJENNerator Rule Configuration • Priority • ViolationMessage
55. @codeJENNerator Rule Configuration • Priority • ViolationMessage • Description
56. @codeJENNerator Rule Configuration • Priority • ViolationMessage • Description • Name
57. @codeJENNerator Rule Configuration
58. @codeJENNerator Rule Configuration • Custom Parameters
59. @codeJENNerator Rule Configuration • Custom Parameters • applyToClassNames
60. @codeJENNerator Rule Configuration • Custom Parameters • applyToClassNames • applyToFileNames
61. @codeJENNerator Ways to add codenarc to your project
62. @codeJENNerator • runs with gradle check https://docs.gradle.org/current/userguide/codenarc_plugin.html
63. @codeJENNerator Config Options
64. @codeJENNerator Config Options • configFile • ignoreFailures • maxPriority1Violations • maxPriority2Violations • maxPriority3Violations
65. @codeJENNerator Config Options
66. @codeJENNerator Config Options • reportFormat • reportsDir • sourceSets • toolVersion
67. @codeJENNerator
68. @codeJENNerator codenarc {
 toolVersion = '0.25.2'
 }
 
 codenarcMain {
 configFile file('config/codenarc/codenarc.groovy')
 }
 
 codenarcTest {
 configFile file('config/codenarc/codenarcTest.groovy')
 }
69. @codeJENNerator • Grails Projects Version < 3.0 • runs with grails codenarc http://grails.org/plugin/codenarc Plugin
70. @codeJENNerator Other Codenarc Plugins
71. @codeJENNerator Other Codenarc Plugins • IDEs • IntelliJ • Eclipse
72. @codeJENNerator Other Codenarc Plugins • IDEs • IntelliJ • Eclipse • Sonar
73. @codeJENNerator Other Codenarc Plugins • IDEs • IntelliJ • Eclipse • Sonar • Maven
74. @codeJENNerator Other Codenarc Plugins • IDEs • IntelliJ • Eclipse • Sonar • Maven • Jenkins (formerly Hudson)
75. @codeJENNerator Reports
76. @codeJENNerator build/reports/codenarc/main.html
77. @codeJENNerator Jenkins Violations Plugin img src: https://leanjavaengineering.wordpress.com/2010/08/25/grails-codenarc-hudson/
78. @codeJENNerator Starter Ruleset http://codenarc.sourceforge.net/StarterRuleSet- AllRulesByCategory.groovy.txt https://flic.kr/p/c8QjRC
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 . . . }
80. @codeJENNerator Turning Off Rules - Comments ruleset { /* // rulesets/braces.xml
 ElseBlockBraces(bracesRequiredForElseIf: true)
 ForStatementBraces
 IfStatementBraces
 WhileStatementBraces */ }
81. @codeJENNerator Turning Off Rules - Enabled:False ruleset { ruleset('rulesets/basic.xml') { CatchThrowable(enabled:false) } }
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')
 }
 }
83. https://flic.kr/p/rmit9T
84. @codeJENNerator 0.21 • No Wildcard Imports • Lots of New Formatting Rules • Consecutive Blank Lines • Blank Line Before Package • FileEndsWithoutNewline
85. @codeJENNerator 0.22 • No Def • Unnecessary Safe Navigation Operator
86. @codeJENNerator 0.23 • Nested For Loop
87. @codeJENNerator 0.25 • No Tab Character • Trailing Comma
88. @codeJENNerator Each Release Improves Existing Rules https://flic.kr/p/3mPXcD
89. @codeJENNerator Rules Worth Talking About
90. @codeJENNerator File Ends Without NewLine
91. @codeJENNerator I don’t like all of the Codenarc Rules! img src: https://flic.kr/p/rehEf5
92. @codeJENNerator Dry • DuplicateListLiteral • DuplicateMapLiteral • DuplicateNumberLiteral • DuplicateStringLiteral
93. @codeJENNerator Could Be Elvis Lots of false positives
94. @codeJENNerator JUnit Ruleset Doesn’t work well with Spock
95. @codeJENNerator No Def https://flic.kr/p/apRkJh
96. @codeJENNerator No Def • Great for Spring Boot https://flic.kr/p/apRkJh
97. @codeJENNerator No Def • Great for Spring Boot • Problematic with Grails https://flic.kr/p/apRkJh
98. @codeJENNerator Good in Theory
99. @codeJENNerator Good in Theory • Unnecessary Return
100. @codeJENNerator Good in Theory • Unnecessary Return • Line Length
101. @codeJENNerator Debatable
102. @codeJENNerator Debatable • Unnecessary Groovy String
103. @codeJENNerator Debatable • Unnecessary Groovy String • Unnecessary Getter
104. @codeJENNerator Debatable
105. @codeJENNerator Debatable • Misordered Static Imports
106. @codeJENNerator Debatable • Misordered Static Imports • No Wildcard Imports
107. @codeJENNerator Still Deciding
108. @codeJENNerator Still Deciding • Complexity Metrics
109. @codeJENNerator WARNING! • Enhanced Ruleset does not work with the gradle codenarc plugin • https://objectpartners.com/2016/03/16/resolving- codenarc-compilation-warnings/
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)
 }
 }
 }
 }
 }
111. @codeJENNerator Contribute • http://codenarc.sourceforge.net/codenarc- developer-guide.html • https://github.com/CodeNarc/CodeNarc
112. @codeJENNerator Read the docs for more on.. • Rule Specifics • Ant Task • Command Line
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
114. @codeJENNerator Conclusion
115. @codeJENNerator Questions? https://flic.kr/p/5DeuzB