A simple code standard for our Groovy/Java code

groovyJavaPractices.groovy

/**
 * Must have copyright statement either of the company or of our client.
 * Follow other files in the repository.
 */
package com.wp.test             // package declaration just after copyright statement

// One line space after package declaration
// Import statement must be organized. Use organize tool in GGTS
import java.text.DateFormat

import com.cc.user.User

// One line space before class declaration
/**
 * Put the class description and javadoc here.
 * 
 * @author shashank             // author
 * @since 3.1.4                 // When this class is introduced
 */
class MainTest {                // There must be a space between class name and curly bracket
                                // Insert one line space after starting of the class declaration

    /**
     * Java constants must be all UPPER case and multi words must be separated by underscores.
     */
    static final BASE_ID = "UID"

    // Don't use "def" when you are sure about data type
    static def somethingGood(int i) {
        return i
    }

    /**
     * Every method must have description and Javadoc.
     * Also if this method was introduced after some time of introducing this class,
     * then Javadoc for this method must have @author & @since properties.
     */
    static void testNow() {     // Space after method declaration and curly bracket
        User userInstance = User.get(2)

        // If either user is missing or their full name is not set (example of inline comment which starts with space)
        if (!userInstance || !userInstance.fullName) {
            return null
        }
        
        // This code is not required (an example for inline comment code without space)
        //userInstance.email = "newemail@gmail.com"

        int i = 0               // There must be space at both sides of equal sign on any operation

        while (i < 4) {         // There must be space after any Java statement and also space before curly bracket
            println("This is okay")
            
            /*
             * Use normal Javadoc with single starting quotes. Since these kind of Javadoc will not be
             * imported when we generate HTML doc for these.
             */
             // No space for ternary operator
            i++
        }
    }

    // There must be no spaces or tabs present in empty line and there must be only one line space between two combinations of method or variables

    /**
     * Try to use reference of custom classes in Javadoc, like given below.
     * 
     * @param userInstance instance of {@link com.cc.user.User User}. Read more on Javadocs
     * @param email new email of the user
     * @return formulated email of the user
     */
    private String anotherFunction(User userInstance, String email) {       // There must be spaces after each argument and argument name must follow variable conventions
        for (int i=0;i<5; i++)              // Must have spaces after operators and semicolons
        {                                   // This bracket must start after previous line with a space
            println("above 2 lines are totally wrong.")
        }

        // Brackets are optional in Groovy while calling a function but we need to use brackets to increase readability
        somethingGood 5                 // This is bad
        somethingGood (5)               // This is again bad
        somethingGood(5)                // This is good

        // Space after "if", before "else"
        if (true != false) {
        } else if (true) {
        }
        
        // Use proper spacing
        User userInstance = new User([
            email: "admin@example.com",
            firstName: "John",
            lastName: "Doe"
        ])
        
        // Return statement are optional in Groovy but you must use return statement to increase code readability
        return "new.formulate.email@example.com"
    }

    /**
     * Although, Groovy doesn't respect Java generics but try using it every places where possible.
     * This helps in faster writing of code if you are using GGTS
     */
    List<String> getNames() {
        List<String> nameList = []

        // This is problematic
        (1..100).each {                 // Groovy closures uses "it" by default. Avoid using "it" variable and define some variable, this may cause some problems (see below)
            nameList << "Name $it"
        }

        // This is absolutely wrong
        (1..100).each {
            ["a", "b"].each {
                nameList << "Name $it"      // You will not be sure that "it" pointing to which loop
            }
        }

        // This is correct
        (1..100).each { number ->
            nameList << "Name $number"
        }

        return nameList
    }

    // Try to keep variables, functions organized if you are adding a new class file (for example). Use GGTS code organizer

    // Variables must be in lower camel case
    float commission_value // Underscores are rarely used by us but besides constants they should't be used in Groovy/Java at all.
    float commissionValue //
    
    String email
    
    // Don't use short names or names must be meaningful
    String f_name
    
    // Do use short names or names that are meaningful
    String fullName
    
    // All indentation must be of 4 spaces not a tab
}