CODEWITHSUNDEEP
checkstyle
Ivan Lymar
Ivan Lymar

Reputation: 2293

Checkstyle if statement rule

Is there any rule that I can use for restricting following if statements :

if ( null == name ) {
...
}

Basically, null should be always on the right side of statement e.g.

if ( name == null ) {
...
}

Upvotes: 1

Views: 450

Answers (1)

rveach
rveach

Reputation: 2201

Sevntu has a custom check called AvoidConstantAsFirstOperandInConditionCheck which does what you want.

$ cat TestClass.java
public class TestClass {
    void method() {
if ( null == name ) {} // violation
if ( name == null ) {} // OK
    }
}

$ cat TestConfig.xml
<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
          "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
          "https://checkstyle.org/dtds/configuration_1_3.dtd">

<module name="Checker">
    <property name="charset" value="UTF-8"/>

    <module name="TreeWalker">
<module name="com.github.sevntu.checkstyle.checks.coding.AvoidConstantAsFirstOperandInConditionCheck" />
    </module>
</module>

$ java -jar checkstyle-8.9-sevntu-1.29.0-all.jar -c TestConfig.xml TestClass.java
Starting audit...
[ERROR] TestClass.java:3: Constant have to be second operand of '=='. [AvoidConstantAsFirstOperandInCondition]
Audit done.
Checkstyle ends with 1 errors.

Upvotes: 2

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