bkdotcom/PHPDebugConsole

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.

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.

If you throw a general exception type, such as ErrorException, RuntimeException, or Exception in a library or framework, it forces consumers to catch all exceptions, including unknown exceptions that they do not know how to handle.

Instead, either throw a subtype that already exists in the Standard PHP Library, or create your own type that derives from Exception.

Noncompliant Code Example

throw new Exception();  // Noncompliant

Compliant Solution

throw new InvalidArgumentException();
// or
throw new UnexpectedValueException();

See

• MITRE, CWE-397 - Declaration of Throws for Generic Exception
• CERT, ERR07-J. - Do not throw RuntimeException, Exception, or Throwable

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.

Having two cases in a switch statement or two branches in an if chain with the same implementation is at best duplicate code, and at worst a coding error. If the same logic is truly needed for both instances, then in an if chain they should be combined, or for a switch, one should fall through to the other.

Noncompliant Code Example

switch ($i) {
  case 1:
    doSomething();
    break;
  case 2:
    doSomethingDifferent();
    break;
  case 3:  // Noncompliant; duplicates case 1's implementation
    doSomething();
    break;
  default:
    doTheRest();
}

if ($a >= 0 && $a < 10) {
  doTheThing();
else if ($a >= 10 && $a < 20) {
  doTheOtherThing();
}
else if ($a >= 20 && $a < 50) {
  doTheThing();  // Noncompliant; duplicates first condition
}
else {
  doTheRest();
}

if ($b == 0) {
  doOneMoreThing();
}
else {
  doOneMoreThing(); // Noncompliant; duplicates then-branch
}

var b = a ? 12 > 4 : 4;  // Noncompliant; always results in the same value

Compliant Solution

switch ($i) {
  case 1:
  case 3:
    doSomething();
    break;
  case 2:
    doSomethingDifferent();
    break;
  default:
    doTheRest();
}

if (($a >= 0 && $a < 10) || ($a >= 20 && $a < 50)) {
  doTheThing();
else if ($a >= 10 && $a < 20) {
  doTheOtherThing();
}
else {
  doTheRest();
}

doOneMoreThing();

b = 4;

or

switch ($i) {
  case 1:
    doSomething();
    break;
  case 2:
    doSomethingDifferent();
    break;
  case 3:
    doThirdThing();
    break;
  default:
    doTheRest();
}

if ($a >= 0 && $a < 10) {
  doTheThing();
else if ($a >= 10 && $a < 20) {
  doTheOtherThing();
}
else if ($a >= 20 && $a < 50) {
  doTheThirdThing();
}
else {
  doTheRest();
}

if ($b == 0) {
  doOneMoreThing();
}
else {
  doTheRest();
}

int b = a ? 12 > 4 : 8;

Exceptions

Blocks in an if chain that contain a single line of code are ignored, as are blocks in a switch statement that contain a single line of code with or without a following break.