Using Conditional Statements with the Xdebug Extension - Extending the xdebug_start_code_coverage() and xdebug_get_code_coverage() functions (
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To be frank, the “xdebug_start_code_coverage()” and “xdebug_get_code_coverage()” functions really start to shine when used to keep track of which lines are executed by a PHP application based on a certain condition.
To exemplify this specific situation, I’m going to use the already familiar “User” class that you learned in the prior section, along with a simple script which will change its execution flow according to a semi-random value generated by the built-in PHP “rand()” function.
Of course, in this case, the “xdebug_start_code_coverage()” and “xdebug_get_code_coverage()” functions will be employed to keep track of which code block is executed by the script in question.
The code sample that shows how to use these functions with a basic conditional statement is as follows:
class User{
private $firstName;
private $lastName;
private $email;
public function __construct($firstName,$lastName,$email){
if(!$firstName){
throw new Exception('Invalid parameter First Name.');
}
if(!$lastName){
throw new Exception('Invalid parameter Last Name.');
}
if(!$email){
throw new Exception('Invalid parameter Email.');
}
$this->firstName=$firstName;
$this->lastName=$lastName;
$this->email=$email;
}
// get first name
public function getFirstName(){
return $this->firstName;
}
// get last name
public function getLastName(){
return $this->lastName;
}
// get email
public function getEmail(){
return $this->email;
}
}
xdebug_start_code_coverage();
$user=new User('John','Doe','john@domain.com');
if(rand(1,10)<5){
echo 'First Name :'.$user->getFirstName().'<br />';
echo 'Last Name :'.$user->getLastName().'<br />';
}
else{
echo 'Email :'.$user->getEmail().'<br />';
}
var_dump(xdebug_get_code_coverage());
/* displays the following when 'rand()' function returns a value < 5
First Name :John
Last Name :Doe
array
'/path/to/example/program_flow_debug.php' =>
array
8 => int 1
11 => int 1
14 => int 1
17 => int 1
18 => int 1
19 => int 1
20 => int 1
23 => int 1
36 => int 1
37 => int 1
38 => int 1
39 => int 1
40 => int 1
44 => int 1
*/
Definitely, the above example shows in a nutshell how useful the “xdebug_start_code_coverage()” and “xdebug_get_code_coverage()” functions can be when it comes to debugging conditional statements within a PHP script.
In this case, the “rand()” PHP native function is utilized in conjunction with an “if” conditional statement to create a simple situation where there are two blocks of code that can be invoked. Logically, this example shows the sequence of lines executed when the “rand()” function returns a value less than 5, in this way demonstrating the functionality of the “xdebug_start_code_coverage()” and “xdebug_get_code_coverage()” functions.
So far, so good, right? You hopefully understand how simple it is to debug conditional statements with the two functions shown before. The previous script would be rather incomplete, however, if I don’t show you the output it produces when the value returned by the “rand()” function is greater than 5.
Therefore, in the last section of this article I will represent this condition through a functional script, in this manner finishing this quick overview on using the “xdebug_start_code_coverage()” and “xdebug_get_code_coverage()” functions included with the X-debug extension.
Click on the link below and read the next few lines, please.
