PHP fopen() error in testing - php

Question

I have the following file structure
src/functions.php
src/sample.csv
tests/functionsTest.php
In the functions.php, I have this function to read a csv file
<?php
function readCSV($csvFile){
$file_handle = fopen($csvFile, 'r');
while (!feof($file_handle) ) {
$line_of_text[] = fgetcsv($file_handle, 1024);
}
fclose($file_handle);
return $line_of_text;
}
?>
In the functionsTest.php file, I have
<?php
require_once('src/functions.php');
use phpunit\framework\TestCase;
class test extends TestCase {
public function testReadDataFromFile() {
$filename = "./sample.csv";
$data = readCSV($filename);
$this->assertEquals("test data", $data);
}
}
?>
When I run the test code using >phpunit tests/functionsTest.php, I get error saying
fopen(./sample.csv): failed to open stream: No such file or directory
But if I call the function from the same src/functions.php, I get the data
print_r(readCSV("sample.csv"));
So I tried to move the sample.csv file to the test folder -
tests/sample.csv
but still I get the same error
I think I am missing something simple.
Can anyone help me with this?

Answer 1

That's because the single dot . represents the current directory. Calling your script from tests/ and specifying . will look for sample.csv in your tests directory, when it's actually in src/.
You want to specify the directory using $filename = "../src/sample.csv";
Also note that you may want to use magic constants instead, or specify an absolute path to the file (e.g. /YourName/YourProject/src/sample.csv), instead of a relative one.
P.S. You can print out those magic constants like __FILE__ and __DIR__ when running your script to troubleshoot issues like this.