Rules to detect constructs that are either broken, extremely confusing or prone to runtime errors.
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AvoidDirectAccessTriggerMap

Since: PMD 6.0.0

Priority: Medium (3)

Avoid directly accessing Trigger.old and Trigger.new as it can lead to a bug. Triggers should be bulkified and iterate through the map to handle the actions for each item separately.

//ArrayLoadExpression/TriggerVariableExpression | //ArrayLoadExpression/LiteralExpression

Example(s):

trigger AccountTrigger on Account (before insert, before update) {
   Account a = Trigger.new[0]; //Bad: Accessing the trigger array directly is not recommended.
   
   foreach ( Account a : Trigger.new ){   
        //Good: Iterate through the trigger.new array instead.
   }
}

This rule has the following properties:

Name Default Value Description
cc_categories [Style] Code Climate Categories
cc_remediation_points_multiplier 1 Code Climate Remediation Points multiplier
cc_block_highlighting false Code Climate Block Highlighting

Use this rule by referencing it:

<rule ref="category/apex/errorprone.xml/AvoidDirectAccessTriggerMap" />

AvoidHardcodingId

Since: PMD 6.0.0

Priority: Medium (3)

When deploying Apex code between sandbox and production environments, or installing Force.com AppExchange packages, it is essential to avoid hardcoding IDs in the Apex code. By doing so, if the record IDs change between environments, the logic can dynamically identify the proper data to operate against and not fail.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.errorprone.AvoidHardcodingIdRule

Example(s):

public without sharing class Foo {
    void foo() {
        //Error - hardcoded the record type id
        if(a.RecordTypeId == '012500000009WAr'){
            //do some logic here.....
        } else if(a.RecordTypeId == '0123000000095Km'){
            //do some logic here for a different record type...
        }
    }
}

This rule has the following properties:

Name Default Value Description
cc_categories [Style] Code Climate Categories
cc_remediation_points_multiplier 1 Code Climate Remediation Points multiplier
cc_block_highlighting false Code Climate Block Highlighting

Use this rule by referencing it:

<rule ref="category/apex/errorprone.xml/AvoidHardcodingId" />

EmptyCatchBlock

Since: PMD 6.0.0

Priority: Medium (3)

Empty Catch Block finds instances where an exception is caught, but nothing is done.
In most circumstances, this swallows an exception which should either be acted on or reported.

//CatchBlockStatement[./BlockStatement[count(*) = 0]]

Example(s):

public void doSomething() {
  ...
  try {
    insert accounts;
  } catch (DmlException dmle) {
    // not good
  }
}

This rule has the following properties:

Name Default Value Description
cc_categories [Style] Code Climate Categories
cc_remediation_points_multiplier 1 Code Climate Remediation Points multiplier
cc_block_highlighting false Code Climate Block Highlighting

Use this rule by referencing it:

<rule ref="category/apex/errorprone.xml/EmptyCatchBlock" />

EmptyIfStmt

Since: PMD 6.0.0

Priority: Medium (3)

Empty If Statement finds instances where a condition is checked but nothing is done about it.

//IfBlockStatement
 [BlockStatement[count(*) = 0]]

Example(s):

public class Foo {
  public void bar(Integer x) {
    if (x == 0) {
      // empty!
    }
  }
}

This rule has the following properties:

Name Default Value Description
cc_categories [Style] Code Climate Categories
cc_remediation_points_multiplier 1 Code Climate Remediation Points multiplier
cc_block_highlighting false Code Climate Block Highlighting

Use this rule by referencing it:

<rule ref="category/apex/errorprone.xml/EmptyIfStmt" />

EmptyStatementBlock

Since: PMD 6.0.0

Priority: Medium (3)

Empty block statements serve no purpose and should be removed.

//Method/ModifierNode[@Abstract!='true' and ../BlockStatement[count(*) = 0]]
| //Method/BlockStatement//BlockStatement[count(*) = 0]

Example(s):

public class Foo {

   private int _bar;

   public void setBar(int bar) {
        // empty
   }

}

This rule has the following properties:

Name Default Value Description
cc_categories [Style] Code Climate Categories
cc_remediation_points_multiplier 1 Code Climate Remediation Points multiplier
cc_block_highlighting false Code Climate Block Highlighting

Use this rule by referencing it:

<rule ref="category/apex/errorprone.xml/EmptyStatementBlock" />

EmptyTryOrFinallyBlock

Since: PMD 6.0.0

Priority: Medium (3)

Avoid empty try or finally blocks - what’s the point?

//TryCatchFinallyBlockStatement[./BlockStatement[count(*) = 0]]

Example(s):

public class Foo {
    public void bar() {
        try {
          // empty !
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

public class Foo {
    public void bar() {
        try {
            int x=2;
        } finally {
            // empty!
        }
    }
}

This rule has the following properties:

Name Default Value Description
cc_categories [Style] Code Climate Categories
cc_remediation_points_multiplier 1 Code Climate Remediation Points multiplier
cc_block_highlighting false Code Climate Block Highlighting

Use this rule by referencing it:

<rule ref="category/apex/errorprone.xml/EmptyTryOrFinallyBlock" />

EmptyWhileStmt

Since: PMD 6.0.0

Priority: Medium (3)

Empty While Statement finds all instances where a while statement does nothing.
If it is a timing loop, then you should use Thread.sleep() for it; if it is a while loop that does a lot in the exit expression, rewrite it to make it clearer.

//WhileLoopStatement[./BlockStatement[count(*) = 0]]

Example(s):

public void bar(Integer a, Integer b) {
  while (a == b) {
    // empty!
  }
}

This rule has the following properties:

Name Default Value Description
cc_categories [Style] Code Climate Categories
cc_remediation_points_multiplier 1 Code Climate Remediation Points multiplier
cc_block_highlighting false Code Climate Block Highlighting

Use this rule by referencing it:

<rule ref="category/apex/errorprone.xml/EmptyWhileStmt" />

MethodWithSameNameAsEnclosingClass

Since: PMD 5.5.0

Priority: Medium (3)

Non-constructor methods should not have the same name as the enclosing class.

This rule is defined by the following Java class: net.sourceforge.pmd.lang.apex.rule.errorprone.MethodWithSameNameAsEnclosingClassRule

Example(s):

public class MyClass {
    // this is OK because it is a constructor
    public MyClass() {}
    // this is bad because it is a method
    public void MyClass() {}
}

This rule has the following properties:

Name Default Value Description
cc_categories [Style] Code Climate Categories
cc_remediation_points_multiplier 1 Code Climate Remediation Points multiplier
cc_block_highlighting false Code Climate Block Highlighting

Use this rule by referencing it:

<rule ref="category/apex/errorprone.xml/MethodWithSameNameAsEnclosingClass" />