bkdotcom/PHPDebugConsole

Having too many return statements in a function increases the function's essential complexity because the flow of execution is broken each time a return statement is encountered. This makes it harder to read and understand the logic of the function.

Noncompliant Code Example

With the default threshold of 3:

function myFunction(){ // Noncompliant as there are 4 return statements
  if (condition1) {
    return true;
  } else {
    if (condition2) {
      return false;
    } else {
      return true;
    }
  }
  return false;
}

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

In PHP 4, any function with the same name as the nesting class was considered a class constructor. In PHP 5, this mechanism has been deprecated and the "__construct" method name should be used instead. If both styles are present in the same class, PHP 5 will treat the function named "__construct" as the class constructor.

This rule rule raises an issue for each method with the same name as the enclosing class.

Noncompliant Code Example

class Foo {
  function Foo(){...}
}

Compliant Solution

class Foo {
  function __construct(){...}
}

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

private methods that are never executed are dead code: unnecessary, inoperative code that should be removed. Cleaning out dead code decreases the size of the maintained codebase, making it easier to understand the program and preventing bugs from being introduced.

Noncompliant Code Example

public class Foo
{
  private function Foo() {}   // Compliant, private empty constructor intentionally used to prevent any direct instantiation of a class.

  public static function doSomething()
  {
    $foo = new Foo();
    ...
  }

  private function unusedPrivateFunction() {  // Noncompliant
  }
}

Compliant Solution

public class Foo
{
  private function Foo(){}   // Compliant, private empty constructor intentionally used to prevent any direct instantiation of a class.

  public static function doSomething()
  {
    $foo = new Foo();
  }
}

See

• CERT, MSC07-CPP. - Detect and remove dead code

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Having too many return statements in a function increases the function's essential complexity because the flow of execution is broken each time a return statement is encountered. This makes it harder to read and understand the logic of the function.

Noncompliant Code Example

With the default threshold of 3:

function myFunction(){ // Noncompliant as there are 4 return statements
  if (condition1) {
    return true;
  } else {
    if (condition2) {
      return false;
    } else {
      return true;
    }
  }
  return false;
}

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Shadowing fields with a local variable is a bad practice that reduces code readability: it makes it confusing to know whether the field or the variable is being used.

Noncompliant Code Example

class Foo {
  public $myField;

  public function doSomething() {
    $myField = 0;
    ...
  }
}

See

• CERT, DCL51-J. - Do not shadow or obscure identifiers in subscopes

The requirement for a final case default clause is defensive programming. The clause should either take appropriate action, or contain a suitable comment as to why no action is taken. Even when the switch covers all current values of an enum, a default case should still be used because there is no guarantee that the enum won't be extended.

Noncompliant Code Example

switch ($param) {  //missing default clause
  case 0:
    do_something();
    break;
  case 1:
    do_something_else();
    break;
}

switch ($param) {
  default: // default clause should be the last one
    error();
    break;
  case 0:
    do_something();
    break;
  case 1:
    do_something_else();
    break;
}

Compliant Solution

switch ($param) {
  case 0:
    do_something();
    break;
  case 1:
    do_something_else();
    break;
  default:
    error();
    break;
}

See

• MISRA C:2004, 15.0 - The MISRA C switch syntax shall be used.
• MISRA C:2004, 15.3 - The final clause of a switch statement shall be the default clause
• MISRA C++:2008, 6-4-3 - A switch statement shall be a well-formed switch statement.
• MISRA C++:2008, 6-4-6 - The final clause of a switch statement shall be the default-clause
• MISRA C:2012, 16.1 - All switch statements shall be well-formed
• MISRA C:2012, 16.4 - Every switch statement shall have a default label
• MISRA C:2012, 16.5 - A default label shall appear as either the first or the last switch label of a switch statement
• MITRE, CWE-478 - Missing Default Case in Switch Statement
• CERT, MSC01-C. - Strive for logical completeness
• CERT, MSC01-CPP. - Strive for logical completeness

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.

There is no good reason to create a new object to not do anything with it. Most of the time, this is due to a missing piece of code and so could lead to an unexpected behavior in production.

If it was done on purpose because the constructor has side-effects, then that side-effect code should be moved into a separate, static method and called directly.

Noncompliant Code Example

if ($x < 0) {
  new foo;  // Noncompliant
}

Compliant Solution

$var = NULL;
if ($x < 0) {
  $var = new foo;
}

Duplicated string literals make the process of refactoring error-prone, since you must be sure to update all occurrences.

On the other hand, constants can be referenced from many places, but only need to be updated in a single place.

Noncompliant Code Example

With the default threshold of 3:

function run() {
  prepare('action1');                              // Non-Compliant - 'action1' is duplicated 3 times
  execute('action1');
  release('action1');
}

Compliant Solution

ACTION_1 = 'action1';

function run() {
  prepare(ACTION_1);
  execute(ACTION_1);
  release(ACTION_1);
}

Exceptions

To prevent generating some false-positives, literals having less than 5 characters are excluded.