Variable reassignment check

tldr; Sonar plugin providing check that reports when local variable / method parameter is being reassigned.

Reassigning variables (oh, the irony) adds unnecessary layer of complexity to the code and, in most cases it means that the code could be better (for example, some parts could be extracted to another method).

Table of contents

• Introduction
• Examples
• Supported versions
• Usage

Examples

Noncompliant example

void foo(Bar bar) {
  String barName = bar.getName();
  if (barName == null) {
    barName = "defaultName"; // Noncompliant
  }
}

Compliant solution

void foo(Bar bar) {
  String barName = Optional.ofNullable(bar.getName()).orElse("defaultName");
}

Exceptions

• Variables defined in loop's parenthesis, for example for (int i=0; i < size; i++) {}
• Class members

Supported versions

Right now it was only tested on sonarqube-8.3.1, further info will be available soon.

Usage

Sonarqube docs describes very well how to install plugins.

This plugin is not available on the marketplace (it probably never will, one-rule plugin seems like an overkill to be honest, but maybe someday it will become part of something else), so you will have to go with Manual installation. The JAR file is available in releases tab.