Use PHPUnit's FilterMapper

.gitignore

@@ -2,3 +2,4 @@
 /composer.lock
 coverage
 .idea
+/.phpunit.result.cache

README.md

@@ -46,7 +46,8 @@ $shutDownCodeCoverage();
 </phpunit>
 ```
 
-Any configuration directive that's [available in PHPUnit](https://phpunit.de/manual/current/en/appendixes.configuration.html#appendixes.configuration.whitelisting-files) works for this library too.
+Most configuration directives that are [available in PHPUnit](https://phpunit.de/manual/current/en/appendixes.configuration.html#appendixes.configuration.whitelisting-files) work for this library too.
+If you notice that something doesn't work, please submit an issue.
 
 If you don't provide a PHPUnit configuration file, no filters will be applied, so you will get a coverage report for all the code in your project, including vendor and test code if applicable.
 

src/LiveCodeCoverage/CodeCoverageFactory.php

@@ -2,6 +2,7 @@
 
 namespace LiveCodeCoverage;
 
+use PHPUnit\TextUI\XmlConfiguration\CodeCoverage\FilterMapper;
 use PHPUnit\TextUI\XmlConfiguration\Configuration;
 use PHPUnit\TextUI\XmlConfiguration\Loader;
 use SebastianBergmann\CodeCoverage\CodeCoverage;
@@ -26,7 +27,6 @@ public static function createFromPhpUnitConfiguration($phpunitFilePath)
 
     private static function configure(CodeCoverage $codeCoverage, Configuration $configuration)
     {
-        $codeCoverageFilter = $codeCoverage->filter();
         $codeCoverageConfiguration = $configuration->codeCoverage();
 
         // The following code is copied from PHPUnit\TextUI\TestRunner
@@ -44,30 +44,11 @@ private static function configure(CodeCoverage $codeCoverage, Configuration $con
             }
         }
 
-        foreach ($codeCoverageConfiguration->directories() as $directory) {
-            $codeCoverageFilter->includeDirectory(
-                $directory->path(),
-                $directory->suffix(),
-                $directory->prefix()
-            );
-        }
-
-        foreach ($codeCoverageConfiguration->files() as $file) {
-            $codeCoverageFilter->includeFile($file->path());
-        }
-
-        foreach ($codeCoverageConfiguration->excludeDirectories() as $directory) {
-            $codeCoverageFilter->excludeDirectory(
-                $directory->path(),
-                $directory->suffix(),
-                $directory->prefix()
-            );
-        }
-
-        foreach ($codeCoverageConfiguration->excludeFiles() as $file) {
-            $codeCoverageFilter->excludeFile($file->path());
-        }
-
+        /*
+         * `FilterMapper` is not covered by PHPUnit's backward-compatibility promise, but let's use it instead of
+         * copying it.
+         */
+        (new FilterMapper())->map($codeCoverage->filter(), $configuration->codeCoverage());
     }
 
     /**