21 Apr 2016

Codenarc in Grails 3

Codenarc is a code analysis tool to help you avoid simple mistakes in your groovy and Grails code.

In Grails 2 there is a codenarc plugin available. Since Grails 3 uses gradle for it’s build tool we can take advantage of gradle plugins - no need for a Grails 3 specific codenarc plugin since gralde has one.

This is another great advantage Grails 3 has - using other tools in a standard way greatly expands whats possible with Grails without the need for custom plugins or solutions.

Quick start

It’s quite easy to apply the codenarc plugin in your build.gradle:

// This is all thats nessisarry if you want to use the default version
// of codenarc and the `config/codenarc/condenarc.xml`
apply plugin: 'codenarc'

// Use the latest version
codenarc {
    toolVersion = '0.25.2'
}

Codenarc need to know what rules to apply to your project.

Here you can set what rules you’d like to include or exclude:

<ruleset xmlns="http://codenarc.org/ruleset/1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://codenarc.org/ruleset/1.0 http://codenarc.org/ruleset-schema.xsd"
         xsi:noNamespaceSchemaLocation="http://codenarc.org/ruleset-schema.xs">

    <ruleset-ref path='rulesets/basic.xml'>
        <!--<exclude name='ExplicitHashSetInstantiation'/>-->
    </ruleset-ref>
    <ruleset-ref path='rulesets/grails.xml'/>
    <ruleset-ref path='rulesets/groovyism.xml'/>
    <ruleset-ref path='rulesets/braces.xml'/>
    <ruleset-ref path='rulesets/imports.xml'/>
    <ruleset-ref path='rulesets/naming.xml'>
        <rule-config name='ClassName'>
            <property name='regex' value='^[A-Z][\$a-zA-Z0-9]*$'/>
        </rule-config>
        <rule-config name='FieldName'>
            <property name='finalRegex' value='^[A-Za-z][a-zA-Z0-9]*$'/>
        </rule-config>
        <rule-config name='MethodName'>
            <property name='regex' value='^[a-z][\$_a-zA-Z0-9]*$|^.*\s.*$'/>
        </rule-config>
        <rule-config name='VariableName'>
            <property name='finalRegex' value='^[a-z][a-zA-Z0-9]*$'/>
        </rule-config>
    </ruleset-ref>
</ruleset>

You can find a complete list of rules here - http://codenarc.sourceforge.net/codenarc-rule-index.html

Note: The rules (such as rulesets/grails.xml) is not a file you need to include in your project. It is distributed with codenarc.

You can use the groovy DSL as well. A Grails 3 example from Jenn Strateris here - https://github.com/jlstrater/gr8data/tree/master/config/codenarc

Last you can run ./gradlew check to run codenarc on your code. You’ll get a html report to review (or add it into your Jenkins reporting).

Continue customization

If you want to use the groovy dsl and/or apply different rules to tests vs app code, add this to your build.gradle

// These rules will be applied to app code
codenarcMain {
    configFile file('config/codenarc/codenarc.groovy')
}

// These rules will be applied to tests only
codenarcTest {
    configFile file('config/codenarc/codenarcTest.groovy')
}

Full codenarc gradle plugin API is here: https://docs.gradle.org/current/userguide/codenarc_plugin.html

Additional links:

• http://groovycalamari.com/issues/27

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