TestSuiteBuilder.php

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<?php
 
declare( strict_types = 1 );
 
namespace MediaWiki\Composer\PhpUnitSplitter;
 
class TestSuiteBuilder {
 
    private static function sortByTimeDescending( TestDescriptor $a, TestDescriptor $b ): int {
        if ( $a->getDuration() === $b->getDuration() ) {
            return 0;
        }
        return ( $a->getDuration() > $b->getDuration() ? -1 : 1 );
    }
 
    private static function smallestGroup( array $suites ): int {
        $min = 10000;
        $minIndex = 0;
        $groups = count( $suites );
        for ( $i = 0; $i < $groups; $i++ ) {
            if ( $suites[$i]["time"] < $min ) {
                $min = $suites[$i]["time"];
                $minIndex = $i;
            }
        }
        return $minIndex;
    }
 
    public function buildSuites( array $testDescriptors, int $groups ): array {
        $suites = array_fill( 0, $groups, [ "list" => [], "time" => 0 ] );
        $roundRobin = 0;
        usort( $testDescriptors, [ self::class, "sortByTimeDescending" ] );
        foreach ( $testDescriptors as $testDescriptor ) {
            if ( !$testDescriptor->getFilename() ) {
                // We didn't resolve a matching file for this test, so we skip it
                // from the suite here. This only happens for "known" missing test
                // classes (see PhpUnitXmlManager::EXPECTED_MISSING_CLASSES) - in
                // all other cases a missing test file will throw an exception during
                // suite building.
                continue;
            }
            if ( $testDescriptor->getDuration() === 0 ) {
                // If no explicit timing information is available for a test, we just
                // drop it round-robin into the next bucket.
                $nextSuite = $roundRobin;
                $roundRobin = ( $roundRobin + 1 ) % $groups;
            } else {
                // If we have information about the test duration, we try and balance
                // out the tests suites by having an even amount of time spent on
                // each suite.
                $nextSuite = self::smallestGroup( $suites );
            }
            $suites[$nextSuite]["list"][] = $testDescriptor->getFilename();
            $suites[$nextSuite]["time"] += $testDescriptor->getDuration();
        }
        return $suites;
    }
}