Composer: Troubleshooting autoloading - composer-php

Question

I'm submitting this question because I have been searching on the topic of troubleshooting autoloading in Composer and can't seem to find anything straightforward. I added several classes to a library and then referenced them in a project. The project can't find the classes. Here are the pertinent facts:
• I've already been using the library in the project for some time.
• I double-checked the namespace declaration in the code file for the class in the library:
namespace \Library\Package\Subpackage;
class Widget { ...
• I double-checked the use statement that aliases the library and the instantiation:
use \Library\Package\Subpackage as Subpackage;
$e = new Subpackage\Widget();
• For grins, I altered the alias:
use \Library\Package\Subpackage\Widget as Widget;
$e = new Widget();
• For even more grins, I tried a direct reference:
$e = new \Library\Package\Subpackage\Widget();
• I also made sure to composer update and make sure the file is actually there, at the right path:
composer update
find . -name Widget.php
./vendor/organization/library/Package/Subpackage/Widget.php
• As a sanity check, I added a reference to another item in the same library but in a different subpackage.
$f = new \Library\Package2\Widget2(); // this works fine
• As an absolute last resort, I put the reference in a PHP file all by itself and ran that.
require_once __DIR__.'/vendor/autoload.php';
$e = new \Library\Package\Subpackage\Widget();
• And for the coup de grace, I wrote a unit test that checks every file in the library's vendor folder:
class AutoloadTest extends \PHPUnit\Framework\TestCase
{
public function classDataProvider()
{
$data = array();
$path = realpath('organization/library/Package/');
$directory_iterator = new \RecursiveDirectoryIterator($path);
$iterator_iterator = new \RecursiveIteratorIterator($directory_iterator);
foreach ($iterator_iterator as $iterator_result) {
$real_path = $iterator_result->getRealPath();
if (substr($real_path, -4, 4) != '.php') {
continue;
}
$split = explode('organization/library/Package/', $real_path);
$processed_path = substr($split[1], 0, -4);
$class_fqname = sprintf('\Library\%s', str_replace("/", '\\', $processed_path));
$data[] = array($class_fqname);
}
return $data;
}
public function test($class_name)
{
$assertion = class_exists($class_name) || trait_exists($class_name) || interface_exists($class_name);
$this->assertTrue($assertion, "$class_name is not recognized as a class, trait or interface.");
}
}
My questions are:
What is the most likely culprit?
What can I do with Composer to get tracing information about the paths that it is trying? Is there some way to feed Composer a path and have it tell me whether or not it can resolve it?

Answer 1

Extraneous backslash.
namespace \Library\Package\Subpackage;
^ oops!
Removing this backslash resolved the problem.
Ultimately, the unit test that I wrote helped me find and resolve the problem. So for the second part of my question, I'm offering the test class that I wrote. The provider receives pairs of the path to scan and the namespace in which the files belong. It scans the paths given and finds the classes in that namespace. The test checks asserts that each qualified-class name corresponds to a class, trait or interface. (Requires an autoloader to load the classes, of course.)
abstract class AutoloadTestBase extends \PHPUnit\Framework\TestCase
{
public function pathProvider()
{
$data = array();
foreach ($this->directories() as $directory_specification) {
list($path, $namespace) = $directory_specification;
if (empty($path)) {
continue;
}
$directory_iterator = new \RecursiveDirectoryIterator($path);
$iterator_iterator = new \RecursiveIteratorIterator($directory_iterator);
foreach ($iterator_iterator as $iterator_result) {
$real_path = $iterator_result->getRealPath();
$split1 = explode($path.'/', $real_path);
if (count($split1) < 2) {
continue;
}
$success = preg_match('/^(.+)\.php$/', $split1[1], $split2);
if (!$success || substr($split2[1], 0, 5) == 'Tests') {
continue;
}
$class_fqname = sprintf('%s\%s', $namespace, str_replace("/", '\\', $split2[1]));
$data[] = array($class_fqname);
}
}
return $data;
}
/**
* #dataProvider pathProvider
*/
public function test($class_name)
{
$assertion = class_exists($class_name) || trait_exists($class_name) || interface_exists($class_name);
$this->assertTrue($assertion, "$class_name is not recognized as a class, trait or interface.");
}
}
class AutoloadTest extends AutoloadTestBase
{
protected function directories()
{
return array(
array('Package1/Subpackage1','\Library1\Package1\Subpackage1'),
array('vendor/organization2/package2/Subpackage2','\Library2\Package2\Subpackage2')
);
}
}