From b5a8841d2459024c8f28620f7e84c8e1097133e4 Mon Sep 17 00:00:00 2001
From: Markus Staab <markus.staab@redaxo.de>
Date: Thu, 20 Nov 2025 16:50:07 +0100
Subject: [PATCH] Drop DOM dependency

---
 composer.json                                 | 132 +++++++++---------
 src/Report/Xml/BuildInformation.php           |  52 +++----
 src/Report/Xml/Coverage.php                   |  26 ++--
 src/Report/Xml/Facade.php                     |  89 ++++++++----
 src/Report/Xml/File.php                       |  54 ++-----
 src/Report/Xml/Method.php                     |  24 ++--
 src/Report/Xml/Node.php                       |  56 ++------
 src/Report/Xml/Project.php                    |  56 +++-----
 src/Report/Xml/Report.php                     |  70 +++-------
 src/Report/Xml/Source.php                     |  17 +--
 src/Report/Xml/Tests.php                      |  24 ++--
 src/Report/Xml/Totals.php                     |  94 +++++--------
 src/Report/Xml/Unit.php                       |  42 ++----
 .../BankAccount.php.xml                       |   2 +-
 ..._with_class_and_anonymous_function.php.xml |   2 +-
 .../source_with_ignore.php.xml                |   2 +-
 16 files changed, 301 insertions(+), 441 deletions(-)

diff --git a/composer.json b/composer.json
index 744507de0..259a58caa 100644
--- a/composer.json
+++ b/composer.json
@@ -1,67 +1,73 @@
 {
-    "name": "phpunit/php-code-coverage",
-    "description": "Library that provides collection, processing, and rendering functionality for PHP code coverage information.",
-    "type": "library",
-    "keywords": [
-        "coverage",
-        "testing",
-        "xunit"
-    ],
-    "homepage": "https://github.com/sebastianbergmann/php-code-coverage",
-    "license": "BSD-3-Clause",
-    "authors": [
-        {
-            "name": "Sebastian Bergmann",
-            "email": "sebastian@phpunit.de",
-            "role": "lead"
-        }
-    ],
-    "support": {
-        "issues": "https://github.com/sebastianbergmann/php-code-coverage/issues",
-        "security": "https://github.com/sebastianbergmann/php-code-coverage/security/policy"
-    },
-    "config": {
-        "platform": {
-            "php": "8.3.0"
-        },
-        "optimize-autoloader": true,
-        "sort-packages": true
-    },
-    "prefer-stable": true,
-    "require": {
-        "php": ">=8.3",
-        "ext-dom": "*",
-        "ext-libxml": "*",
-        "ext-xmlwriter": "*",
-        "nikic/php-parser": "^5.6.1",
-        "phpunit/php-file-iterator": "^6.0",
-        "phpunit/php-text-template": "^5.0",
-        "sebastian/complexity": "^5.0",
-        "sebastian/environment": "^8.0.3",
-        "sebastian/lines-of-code": "^4.0",
-        "sebastian/version": "^6.0",
-        "theseer/tokenizer": "^1.2.3"
-    },
-    "require-dev": {
-        "phpunit/phpunit": "^12.3.7"
-    },
-    "suggest": {
-        "ext-pcov": "PHP extension that provides line coverage",
-        "ext-xdebug": "PHP extension that provides line coverage as well as branch and path coverage"
-    },
-    "autoload": {
-        "classmap": [
-            "src/"
-        ]
-    },
-    "autoload-dev": {
-        "classmap": [
-            "tests/"
-        ]
+  "name": "phpunit/php-code-coverage",
+  "description": "Library that provides collection, processing, and rendering functionality for PHP code coverage information.",
+  "type": "library",
+  "keywords": [
+    "coverage",
+    "testing",
+    "xunit"
+  ],
+  "homepage": "https://github.com/sebastianbergmann/php-code-coverage",
+  "license": "BSD-3-Clause",
+  "authors": [
+    {
+      "name": "Sebastian Bergmann",
+      "email": "sebastian@phpunit.de",
+      "role": "lead"
+    }
+  ],
+  "support": {
+    "issues": "https://github.com/sebastianbergmann/php-code-coverage/issues",
+    "security": "https://github.com/sebastianbergmann/php-code-coverage/security/policy"
+  },
+  "config": {
+    "platform": {
+      "php": "8.3.0"
     },
-    "extra": {
-        "branch-alias": {
-            "dev-main": "12.4.x-dev"
-        }
+    "optimize-autoloader": true,
+    "sort-packages": true
+  },
+  "prefer-stable": true,
+  "require": {
+    "php": ">=8.3",
+    "ext-dom": "*",
+    "ext-libxml": "*",
+    "ext-xmlwriter": "*",
+    "nikic/php-parser": "^5.6.1",
+    "phpunit/php-file-iterator": "^6.0",
+    "phpunit/php-text-template": "^5.0",
+    "sebastian/complexity": "^5.0",
+    "sebastian/environment": "^8.0.3",
+    "sebastian/lines-of-code": "^4.0",
+    "sebastian/version": "^6.0",
+    "theseer/tokenizer": "dev-writer as 1.3-dev"
+  },
+  "require-dev": {
+    "phpunit/phpunit": "^12.3.7"
+  },
+  "suggest": {
+    "ext-pcov": "PHP extension that provides line coverage",
+    "ext-xdebug": "PHP extension that provides line coverage as well as branch and path coverage"
+  },
+  "autoload": {
+    "classmap": [
+      "src/"
+    ]
+  },
+  "autoload-dev": {
+    "classmap": [
+      "tests/"
+    ]
+  },
+  "extra": {
+    "branch-alias": {
+      "dev-main": "12.4.x-dev"
+    }
+  },
+  "repositories": [
+    {
+      "type": "vcs",
+      "url": "https://github.com/staabm/tokenizer"
     }
+  ]
 }
diff --git a/src/Report/Xml/BuildInformation.php b/src/Report/Xml/BuildInformation.php
index 654eecb31..b9375f228 100644
--- a/src/Report/Xml/BuildInformation.php
+++ b/src/Report/Xml/BuildInformation.php
@@ -9,63 +9,47 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
-use function assert;
 use function phpversion;
 use DateTimeImmutable;
-use DOMElement;
 use SebastianBergmann\Environment\Runtime;
+use XMLWriter;
 
 /**
  * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
  */
 final readonly class BuildInformation
 {
-    private DOMElement $contextNode;
-
     public function __construct(
-        DOMElement $contextNode,
+        XMLWriter $xmlWriter,
         Runtime $runtime,
         DateTimeImmutable $buildDate,
         string $phpUnitVersion,
         string $coverageVersion
     ) {
-        $this->contextNode = $contextNode;
-
-        $runtimeNode = $this->nodeByName('runtime');
+        $xmlWriter->startElement('build');
+        $xmlWriter->writeAttribute('time', $buildDate->format('D M j G:i:s T Y'));
+        $xmlWriter->writeAttribute('phpunit', $phpUnitVersion);
+        $xmlWriter->writeAttribute('coverage', $coverageVersion);
 
-        $runtimeNode->setAttribute('name', $runtime->getName());
-        $runtimeNode->setAttribute('version', $runtime->getVersion());
-        $runtimeNode->setAttribute('url', $runtime->getVendorUrl());
+        $xmlWriter->startElement('runtime');
+        $xmlWriter->writeAttribute('name', $runtime->getName());
+        $xmlWriter->writeAttribute('version', $runtime->getVersion());
+        $xmlWriter->writeAttribute('url', $runtime->getVendorUrl());
+        $xmlWriter->endElement();
 
-        $driverNode = $this->nodeByName('driver');
+        $xmlWriter->startElement('driver');
 
         if ($runtime->hasXdebug()) {
-            $driverNode->setAttribute('name', 'xdebug');
-            $driverNode->setAttribute('version', phpversion('xdebug'));
+            $xmlWriter->writeAttribute('name', 'xdebug');
+            $xmlWriter->writeAttribute('version', phpversion('xdebug'));
         }
 
         if ($runtime->hasPCOV()) {
-            $driverNode->setAttribute('name', 'pcov');
-            $driverNode->setAttribute('version', phpversion('pcov'));
+            $xmlWriter->writeAttribute('name', 'pcov');
+            $xmlWriter->writeAttribute('version', phpversion('pcov'));
         }
+        $xmlWriter->endElement();
 
-        $this->contextNode->setAttribute('time', $buildDate->format('D M j G:i:s T Y'));
-
-        $this->contextNode->setAttribute('phpunit', $phpUnitVersion);
-        $this->contextNode->setAttribute('coverage', $coverageVersion);
-    }
-
-    private function nodeByName(string $name): DOMElement
-    {
-        $node = $this->contextNode->appendChild(
-            $this->contextNode->ownerDocument->createElementNS(
-                Facade::XML_NAMESPACE,
-                $name,
-            ),
-        );
-
-        assert($node instanceof DOMElement);
-
-        return $node;
+        $xmlWriter->endElement();
     }
 }
diff --git a/src/Report/Xml/Coverage.php b/src/Report/Xml/Coverage.php
index 9462780be..3038eb143 100644
--- a/src/Report/Xml/Coverage.php
+++ b/src/Report/Xml/Coverage.php
@@ -9,7 +9,6 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
-use DOMElement;
 use XMLWriter;
 
 /**
@@ -17,20 +16,21 @@
  */
 final class Coverage
 {
-    private readonly DOMElement $contextNode;
+    private readonly XMLWriter $xmlWriter;
     private readonly string $line;
 
-    public function __construct(DOMElement $context, string $line)
-    {
-        $this->contextNode = $context;
-        $this->line        = $line;
+    public function __construct(
+        XMLWriter $xmlWriter,
+        string $line
+    ) {
+        $this->xmlWriter = $xmlWriter;
+        $this->line      = $line;
     }
 
     public function finalize(array $tests): void
     {
-        $writer = new XMLWriter;
-        $writer->openMemory();
-        $writer->startElementNs(null, $this->contextNode->nodeName, Facade::XML_NAMESPACE);
+        $writer = $this->xmlWriter;
+        $writer->startElement('line');
         $writer->writeAttribute('nr', $this->line);
 
         foreach ($tests as $test) {
@@ -39,13 +39,5 @@ public function finalize(array $tests): void
             $writer->endElement();
         }
         $writer->endElement();
-
-        $fragment = $this->contextNode->ownerDocument->createDocumentFragment();
-        $fragment->appendXML($writer->outputMemory());
-
-        $this->contextNode->parentNode->replaceChild(
-            $fragment,
-            $this->contextNode,
-        );
     }
 }
diff --git a/src/Report/Xml/Facade.php b/src/Report/Xml/Facade.php
index c3767088e..cba61f0c2 100644
--- a/src/Report/Xml/Facade.php
+++ b/src/Report/Xml/Facade.php
@@ -21,7 +21,6 @@
 use function strlen;
 use function substr;
 use DateTimeImmutable;
-use DOMDocument;
 use SebastianBergmann\CodeCoverage\CodeCoverage;
 use SebastianBergmann\CodeCoverage\Data\ProcessedClassType;
 use SebastianBergmann\CodeCoverage\Data\ProcessedFunctionType;
@@ -31,11 +30,11 @@
 use SebastianBergmann\CodeCoverage\Node\File as FileNode;
 use SebastianBergmann\CodeCoverage\PathExistsButIsNotDirectoryException;
 use SebastianBergmann\CodeCoverage\Util\Filesystem;
-use SebastianBergmann\CodeCoverage\Util\Xml;
 use SebastianBergmann\CodeCoverage\Version;
 use SebastianBergmann\CodeCoverage\WriteOperationFailedException;
 use SebastianBergmann\CodeCoverage\XmlException;
 use SebastianBergmann\Environment\Runtime;
+use XMLWriter;
 
 /**
  * @phpstan-import-type TestType from CodeCoverage
@@ -66,15 +65,21 @@ public function process(CodeCoverage $coverage, string $target): void
 
         $report = $coverage->getReport();
 
+        $writer = new XMLWriter;
+        $writer->openUri($this->targetFilePath('index'));
+        $writer->setIndent(true);
+        $writer->setIndentString('  ');
         $this->project = new Project(
+            $writer,
             $coverage->getReport()->name(),
         );
 
         $this->setBuildInformation();
+
+        $this->project->startProject();
         $this->processTests($coverage->getTests());
         $this->processDirectory($report, $this->project);
-
-        $this->saveDocument($this->project->asDom(), 'index');
+        $this->project->finalize();
     }
 
     private function setBuildInformation(): void
@@ -119,7 +124,10 @@ private function processDirectory(DirectoryNode $directory, Node $context): void
             $directoryName = '/';
         }
 
-        $directoryObject = $context->addDirectory($directoryName);
+        $writer = $this->project->getWriter();
+        $writer->startElement('directory');
+        $writer->writeAttribute('name', $directoryName);
+        $directoryObject = $context->addDirectory();
 
         $this->setTotals($directory, $directoryObject->totals());
 
@@ -130,6 +138,7 @@ private function processDirectory(DirectoryNode $directory, Node $context): void
         foreach ($directory->files() as $node) {
             $this->processFile($node, $directoryObject);
         }
+        $writer->endElement();
     }
 
     /**
@@ -137,19 +146,26 @@ private function processDirectory(DirectoryNode $directory, Node $context): void
      */
     private function processFile(FileNode $file, Directory $context): void
     {
-        $fileObject = $context->addFile(
-            $file->name(),
-            $file->id() . '.xml',
-        );
+        $context->getWriter()->startElement('file');
+        $context->getWriter()->writeAttribute('name', $file->name());
+        $context->getWriter()->writeAttribute('href', $file->id() . '.xml');
+
+        $fileObject = $context->addFile();
 
         $this->setTotals($file, $fileObject->totals());
 
+        $context->getWriter()->endElement();
+
         $path = substr(
             $file->pathAsString(),
             strlen($this->project->projectSourceDirectory()),
         );
 
-        $fileReport = new Report($path);
+        $writer = new XMLWriter;
+        $writer->openUri($this->targetFilePath($file->id()));
+        $writer->setIndent(true);
+        $writer->setIndentString('  ');
+        $fileReport = new Report($writer, $path);
 
         $this->setTotals($file, $fileReport->totals());
 
@@ -161,6 +177,8 @@ private function processFile(FileNode $file, Directory $context): void
             $this->processFunction($function, $fileReport);
         }
 
+        $fileReport->getWriter()->startElement('coverage');
+
         foreach ($file->lineCoverageData() as $line => $tests) {
             if (!is_array($tests) || count($tests) === 0) {
                 continue;
@@ -169,17 +187,20 @@ private function processFile(FileNode $file, Directory $context): void
             $coverage = $fileReport->lineCoverage((string) $line);
             $coverage->finalize($tests);
         }
+        $fileReport->getWriter()->endElement();
 
         $fileReport->source()->setSourceCode(
             file_get_contents($file->pathAsString()),
         );
 
-        $this->saveDocument($fileReport->asDom(), $file->id());
+        $fileReport->finalize();
     }
 
     private function processUnit(ProcessedClassType|ProcessedTraitType $unit, Report $report): void
     {
         if ($unit instanceof ProcessedClassType) {
+            $report->getWriter()->startElement('class');
+
             $unitObject = $report->classObject(
                 $unit->className,
                 $unit->namespace,
@@ -189,6 +210,8 @@ private function processUnit(ProcessedClassType|ProcessedTraitType $unit, Report
                 (float) $unit->crap,
             );
         } else {
+            $report->getWriter()->startElement('trait');
+
             $unitObject = $report->traitObject(
                 $unit->traitName,
                 $unit->namespace,
@@ -200,6 +223,8 @@ private function processUnit(ProcessedClassType|ProcessedTraitType $unit, Report
         }
 
         foreach ($unit->methods as $method) {
+            $report->getWriter()->startElement('method');
+
             $unitObject->addMethod(
                 $method->methodName,
                 $method->signature,
@@ -210,11 +235,17 @@ private function processUnit(ProcessedClassType|ProcessedTraitType $unit, Report
                 (string) $method->coverage,
                 $method->crap,
             );
+
+            $report->getWriter()->endElement();
         }
+
+        $report->getWriter()->endElement();
     }
 
     private function processFunction(ProcessedFunctionType $function, Report $report): void
     {
+        $report->getWriter()->startElement('function');
+
         $report->functionObject(
             $function->functionName,
             $function->signature,
@@ -225,6 +256,8 @@ private function processFunction(ProcessedFunctionType $function, Report $report
             (string) $function->coverage,
             $function->crap,
         );
+
+        $report->getWriter()->endElement();
     }
 
     /**
@@ -232,15 +265,21 @@ private function processFunction(ProcessedFunctionType $function, Report $report
      */
     private function processTests(array $tests): void
     {
+        $this->project->getWriter()->startElement('tests');
+
         $testsObject = $this->project->tests();
 
         foreach ($tests as $test => $result) {
             $testsObject->addTest($test, $result);
         }
+
+        $this->project->getWriter()->endElement();
     }
 
     private function setTotals(AbstractNode $node, Totals $totals): void
     {
+        $totals->getWriter()->startElement('totals');
+
         $loc = $node->linesOfCode();
 
         $totals->setNumLines(
@@ -251,6 +290,16 @@ private function setTotals(AbstractNode $node, Totals $totals): void
             $node->numberOfExecutedLines(),
         );
 
+        $totals->setNumMethods(
+            $node->numberOfMethods(),
+            $node->numberOfTestedMethods(),
+        );
+
+        $totals->setNumFunctions(
+            $node->numberOfFunctions(),
+            $node->numberOfTestedFunctions(),
+        );
+
         $totals->setNumClasses(
             $node->numberOfClasses(),
             $node->numberOfTestedClasses(),
@@ -261,15 +310,7 @@ private function setTotals(AbstractNode $node, Totals $totals): void
             $node->numberOfTestedTraits(),
         );
 
-        $totals->setNumMethods(
-            $node->numberOfMethods(),
-            $node->numberOfTestedMethods(),
-        );
-
-        $totals->setNumFunctions(
-            $node->numberOfFunctions(),
-            $node->numberOfTestedFunctions(),
-        );
+        $totals->getWriter()->endElement();
     }
 
     private function targetDirectory(): string
@@ -285,12 +326,4 @@ private function targetFilePath(string $name): string
 
         return $filename;
     }
-
-    /**
-     * @throws XmlException
-     */
-    private function saveDocument(DOMDocument $document, string $name): void
-    {
-        Filesystem::write($this->targetFilePath($name), Xml::asString($document));
-    }
 }
diff --git a/src/Report/Xml/File.php b/src/Report/Xml/File.php
index e6dd5c4ba..2d35582a8 100644
--- a/src/Report/Xml/File.php
+++ b/src/Report/Xml/File.php
@@ -9,66 +9,32 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
-use function assert;
-use DOMDocument;
-use DOMElement;
-use DOMNode;
+use XMLWriter;
 
 /**
  * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
  */
 class File
 {
-    protected readonly DOMDocument $dom;
-    private readonly DOMElement $contextNode;
-    private ?DOMNode $lineCoverage = null;
+    protected XMLWriter $xmlWriter;
 
-    public function __construct(DOMElement $context)
+    public function __construct(XMLWriter $xmlWriter)
     {
-        $this->dom         = $context->ownerDocument;
-        $this->contextNode = $context;
+        $this->xmlWriter = $xmlWriter;
     }
 
-    public function totals(): Totals
+    public function getWriter(): XMLWriter
     {
-        $totalsContainer = $this->contextNode->appendChild(
-            $this->dom->createElementNS(
-                Facade::XML_NAMESPACE,
-                'totals',
-            ),
-        );
-
-        assert($totalsContainer instanceof DOMElement);
-
-        return new Totals($totalsContainer);
+        return $this->xmlWriter;
     }
 
-    public function lineCoverage(string $line): Coverage
+    public function totals(): Totals
     {
-        if ($this->lineCoverage === null) {
-            $this->lineCoverage = $this->contextNode->appendChild(
-                $this->dom->createElementNS(
-                    Facade::XML_NAMESPACE,
-                    'coverage',
-                ),
-            );
-        }
-        assert($this->lineCoverage instanceof DOMElement);
-
-        $lineNode = $this->lineCoverage->appendChild(
-            $this->dom->createElementNS(
-                Facade::XML_NAMESPACE,
-                'line',
-            ),
-        );
-
-        assert($lineNode instanceof DOMElement);
-
-        return new Coverage($lineNode, $line);
+        return new Totals($this->xmlWriter);
     }
 
-    protected function contextNode(): DOMElement
+    public function lineCoverage(string $line): Coverage
     {
-        return $this->contextNode;
+        return new Coverage($this->xmlWriter, $line);
     }
 }
diff --git a/src/Report/Xml/Method.php b/src/Report/Xml/Method.php
index 1b5bdb28f..965ad5259 100644
--- a/src/Report/Xml/Method.php
+++ b/src/Report/Xml/Method.php
@@ -9,17 +9,17 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
-use DOMElement;
+use XMLWriter;
 
 /**
  * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
  */
 final readonly class Method
 {
-    private DOMElement $contextNode;
+    private XMLWriter $xmlWriter;
 
     public function __construct(
-        DOMElement $context,
+        XMLWriter $xmlWriter,
         string $name,
         string $signature,
         string $start,
@@ -29,21 +29,21 @@ public function __construct(
         string $coverage,
         string $crap
     ) {
-        $this->contextNode = $context;
+        $this->xmlWriter = $xmlWriter;
 
-        $this->contextNode->setAttribute('name', $name);
-        $this->contextNode->setAttribute('signature', $signature);
+        $this->xmlWriter->writeAttribute('name', $name);
+        $this->xmlWriter->writeAttribute('signature', $signature);
 
-        $this->contextNode->setAttribute('start', $start);
+        $this->xmlWriter->writeAttribute('start', $start);
 
         if ($end !== null) {
-            $this->contextNode->setAttribute('end', $end);
+            $this->xmlWriter->writeAttribute('end', $end);
         }
 
-        $this->contextNode->setAttribute('crap', $crap);
+        $this->xmlWriter->writeAttribute('crap', $crap);
 
-        $this->contextNode->setAttribute('executable', $executable);
-        $this->contextNode->setAttribute('executed', $executed);
-        $this->contextNode->setAttribute('coverage', $coverage);
+        $this->xmlWriter->writeAttribute('executable', $executable);
+        $this->xmlWriter->writeAttribute('executed', $executed);
+        $this->xmlWriter->writeAttribute('coverage', $coverage);
     }
 }
diff --git a/src/Report/Xml/Node.php b/src/Report/Xml/Node.php
index 86fe70df4..36b75bcfe 100644
--- a/src/Report/Xml/Node.php
+++ b/src/Report/Xml/Node.php
@@ -9,71 +9,37 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
-use function assert;
-use DOMDocument;
-use DOMElement;
+use XMLWriter;
 
 /**
  * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
  */
 abstract class Node
 {
-    protected readonly DOMDocument $dom;
-    private readonly DOMElement $contextNode;
+    protected readonly XMLWriter $xmlWriter;
 
-    public function __construct(DOMElement $context)
+    public function __construct(XMLWriter $xmlWriter)
     {
-        $this->dom         = $context->ownerDocument;
-        $this->contextNode = $context;
+        $this->xmlWriter = $xmlWriter;
     }
 
     public function totals(): Totals
     {
-        $totalsContainer = $this->contextNode()->firstChild;
-
-        if ($totalsContainer === null) {
-            $totalsContainer = $this->contextNode()->appendChild(
-                $this->dom->createElementNS(
-                    Facade::XML_NAMESPACE,
-                    'totals',
-                ),
-            );
-        }
-
-        assert($totalsContainer instanceof DOMElement);
-
-        return new Totals($totalsContainer);
+        return new Totals($this->xmlWriter);
     }
 
-    public function addDirectory(string $name): Directory
+    public function addDirectory(): Directory
     {
-        $dirNode = $this->dom->createElementNS(
-            Facade::XML_NAMESPACE,
-            'directory',
-        );
-
-        $dirNode->setAttribute('name', $name);
-        $this->contextNode()->appendChild($dirNode);
-
-        return new Directory($dirNode);
+        return new Directory($this->xmlWriter);
     }
 
-    public function addFile(string $name, string $href): File
+    public function addFile(): File
     {
-        $fileNode = $this->dom->createElementNS(
-            Facade::XML_NAMESPACE,
-            'file',
-        );
-
-        $fileNode->setAttribute('name', $name);
-        $fileNode->setAttribute('href', $href);
-        $this->contextNode()->appendChild($fileNode);
-
-        return new File($fileNode);
+        return new File($this->xmlWriter);
     }
 
-    protected function contextNode(): DOMElement
+    public function getWriter(): XMLWriter
     {
-        return $this->contextNode;
+        return $this->xmlWriter;
     }
 }
diff --git a/src/Report/Xml/Project.php b/src/Report/Xml/Project.php
index c81a6a933..750908c75 100644
--- a/src/Report/Xml/Project.php
+++ b/src/Report/Xml/Project.php
@@ -9,11 +9,9 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
-use function assert;
 use DateTimeImmutable;
-use DOMDocument;
-use DOMElement;
 use SebastianBergmann\Environment\Runtime;
+use XMLWriter;
 
 /**
  * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
@@ -22,19 +20,16 @@ final class Project extends Node
 {
     private readonly string $directory;
 
-    public function __construct(string $directory)
+    public function __construct(XMLWriter $xmlWriter, string $directory)
     {
-        $dom = new DOMDocument;
-        $dom->loadXML('<?xml version="1.0" ?><phpunit xmlns="https://schema.phpunit.de/coverage/1.0"><build/><project/></phpunit>');
+        $this->directory = $directory;
 
-        parent::__construct(
-            $dom->getElementsByTagNameNS(
-                Facade::XML_NAMESPACE,
-                'project',
-            )->item(0),
-        );
+        parent::__construct($xmlWriter);
 
-        $this->directory = $directory;
+        $this->xmlWriter->startDocument();
+
+        $this->xmlWriter->startElement('phpunit');
+        $this->xmlWriter->writeAttribute('xmlns', Facade::XML_NAMESPACE);
     }
 
     public function projectSourceDirectory(): string
@@ -48,15 +43,8 @@ public function buildInformation(
         string $phpUnitVersion,
         string $coverageVersion
     ): void {
-        $buildNode = $this->dom->getElementsByTagNameNS(
-            Facade::XML_NAMESPACE,
-            'build',
-        )->item(0);
-
-        assert($buildNode instanceof DOMElement);
-
         new BuildInformation(
-            $buildNode,
+            $this->xmlWriter,
             $runtime,
             $buildDate,
             $phpUnitVersion,
@@ -66,22 +54,24 @@ public function buildInformation(
 
     public function tests(): Tests
     {
-        $testsNode = $this->contextNode()->appendChild(
-            $this->dom->createElementNS(
-                Facade::XML_NAMESPACE,
-                'tests',
-            ),
-        );
-
-        assert($testsNode instanceof DOMElement);
+        return new Tests($this->xmlWriter);
+    }
 
-        return new Tests($testsNode);
+    public function getWriter(): XMLWriter
+    {
+        return $this->xmlWriter;
     }
 
-    public function asDom(): DOMDocument
+    public function startProject(): void
     {
-        $this->contextNode()->setAttribute('source', $this->directory);
+        $this->xmlWriter->startElement('project');
+        $this->xmlWriter->writeAttribute('source', $this->directory);
+    }
 
-        return $this->dom;
+    public function finalize(): void
+    {
+        $this->xmlWriter->endElement();
+        $this->xmlWriter->endDocument();
+        $this->xmlWriter->flush();
     }
 }
diff --git a/src/Report/Xml/Report.php b/src/Report/Xml/Report.php
index ee9b401de..8cdc71e44 100644
--- a/src/Report/Xml/Report.php
+++ b/src/Report/Xml/Report.php
@@ -9,11 +9,10 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
-use function assert;
 use function basename;
 use function dirname;
 use DOMDocument;
-use DOMElement;
+use XMLWriter;
 
 /**
  * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
@@ -22,8 +21,9 @@ final class Report extends File
 {
     private readonly string $name;
 
-    public function __construct(string $name)
+    public function __construct(XMLWriter $xmlWriter, string $name)
     {
+        /*
         $dom = new DOMDocument;
         $dom->loadXML('<?xml version="1.0" ?><phpunit xmlns="https://schema.phpunit.de/coverage/1.0"><file /></phpunit>');
 
@@ -31,18 +31,26 @@ public function __construct(string $name)
             Facade::XML_NAMESPACE,
             'file',
         )->item(0);
-
-        parent::__construct($contextNode);
+*/
+        parent::__construct($xmlWriter);
 
         $this->name = $name;
+
+        $xmlWriter->startDocument();
+        $xmlWriter->startElement('phpunit');
+        $xmlWriter->writeAttribute('xmlns', Facade::XML_NAMESPACE);
+        $xmlWriter->startElement('file');
+        $xmlWriter->writeAttribute('name', basename($this->name));
+        $xmlWriter->writeAttribute('path', dirname($this->name));
     }
 
-    public function asDom(): DOMDocument
+    public function finalize(): void
     {
-        $this->contextNode()->setAttribute('name', basename($this->name));
-        $this->contextNode()->setAttribute('path', dirname($this->name));
+        $this->xmlWriter->endElement();
+        $this->xmlWriter->endElement();
 
-        return $this->dom;
+        $this->xmlWriter->endDocument();
+        $this->xmlWriter->flush();
     }
 
     public function functionObject(
@@ -55,17 +63,8 @@ public function functionObject(
         string $coverage,
         string $crap
     ): void {
-        $node = $this->contextNode()->appendChild(
-            $this->dom->createElementNS(
-                Facade::XML_NAMESPACE,
-                'function',
-            ),
-        );
-
-        assert($node instanceof DOMElement);
-
         new Method(
-            $node,
+            $this->xmlWriter,
             $name,
             $signature,
             $start,
@@ -85,16 +84,7 @@ public function classObject(
         int $executed,
         float $crap
     ): Unit {
-        $node = $this->contextNode()->appendChild(
-            $this->dom->createElementNS(
-                Facade::XML_NAMESPACE,
-                'class',
-            ),
-        );
-
-        assert($node instanceof DOMElement);
-
-        return new Unit($node, $name, $namespace, $start, $executable, $executed, $crap);
+        return new Unit($this->xmlWriter, $name, $namespace, $start, $executable, $executed, $crap);
     }
 
     public function traitObject(
@@ -105,29 +95,11 @@ public function traitObject(
         int $executed,
         float $crap
     ): Unit {
-        $node = $this->contextNode()->appendChild(
-            $this->dom->createElementNS(
-                Facade::XML_NAMESPACE,
-                'trait',
-            ),
-        );
-
-        assert($node instanceof DOMElement);
-
-        return new Unit($node, $name, $namespace, $start, $executable, $executed, $crap);
+        return new Unit($this->xmlWriter, $name, $namespace, $start, $executable, $executed, $crap);
     }
 
     public function source(): Source
     {
-        $source = $this->contextNode()->appendChild(
-            $this->dom->createElementNS(
-                Facade::XML_NAMESPACE,
-                'source',
-            ),
-        );
-
-        assert($source instanceof DOMElement);
-
-        return new Source($source);
+        return new Source($this->xmlWriter);
     }
 }
diff --git a/src/Report/Xml/Source.php b/src/Report/Xml/Source.php
index 698a71b6d..e82b2c382 100644
--- a/src/Report/Xml/Source.php
+++ b/src/Report/Xml/Source.php
@@ -9,33 +9,26 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
-use DOMElement;
 use TheSeer\Tokenizer\NamespaceUri;
 use TheSeer\Tokenizer\Tokenizer;
 use TheSeer\Tokenizer\XMLSerializer;
+use XMLWriter;
 
 /**
  * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
  */
 final readonly class Source
 {
-    private DOMElement $context;
+    private XMLWriter $xmlWriter;
 
-    public function __construct(DOMElement $context)
+    public function __construct(XMLWriter $xmlWriter)
     {
-        $this->context = $context;
+        $this->xmlWriter = $xmlWriter;
     }
 
     public function setSourceCode(string $source): void
     {
-        $context = $this->context;
-
         $tokens = (new Tokenizer)->parse($source);
-        $srcDom = (new XMLSerializer(new NamespaceUri(Facade::XML_NAMESPACE)))->toDom($tokens);
-
-        $context->parentNode->replaceChild(
-            $context->ownerDocument->importNode($srcDom->documentElement, true),
-            $context,
-        );
+        (new XMLSerializer(new NamespaceUri(Facade::XML_NAMESPACE)))->appendToWriter($this->xmlWriter, $tokens);
     }
 }
diff --git a/src/Report/Xml/Tests.php b/src/Report/Xml/Tests.php
index 1760fdfa5..3fea6f4d3 100644
--- a/src/Report/Xml/Tests.php
+++ b/src/Report/Xml/Tests.php
@@ -9,9 +9,8 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
-use function assert;
-use DOMElement;
 use SebastianBergmann\CodeCoverage\CodeCoverage;
+use XMLWriter;
 
 /**
  * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
@@ -20,11 +19,11 @@
  */
 final readonly class Tests
 {
-    private DOMElement $contextNode;
+    private readonly XMLWriter $xmlWriter;
 
-    public function __construct(DOMElement $context)
+    public function __construct(XMLWriter $xmlWriter)
     {
-        $this->contextNode = $context;
+        $this->xmlWriter = $xmlWriter;
     }
 
     /**
@@ -32,17 +31,12 @@ public function __construct(DOMElement $context)
      */
     public function addTest(string $test, array $result): void
     {
-        $node = $this->contextNode->appendChild(
-            $this->contextNode->ownerDocument->createElementNS(
-                Facade::XML_NAMESPACE,
-                'test',
-            ),
-        );
+        $this->xmlWriter->startElement('test');
 
-        assert($node instanceof DOMElement);
+        $this->xmlWriter->writeAttribute('name', $test);
+        $this->xmlWriter->writeAttribute('size', $result['size']);
+        $this->xmlWriter->writeAttribute('status', $result['status']);
 
-        $node->setAttribute('name', $test);
-        $node->setAttribute('size', $result['size']);
-        $node->setAttribute('status', $result['status']);
+        $this->xmlWriter->endElement();
     }
 }
diff --git a/src/Report/Xml/Totals.php b/src/Report/Xml/Totals.php
index 28612f7aa..b0c57ec30 100644
--- a/src/Report/Xml/Totals.php
+++ b/src/Report/Xml/Totals.php
@@ -10,106 +10,86 @@
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
 use function sprintf;
-use DOMElement;
 use SebastianBergmann\CodeCoverage\Util\Percentage;
+use XMLWriter;
 
 /**
  * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
  */
 final readonly class Totals
 {
-    private DOMElement $linesNode;
-    private DOMElement $methodsNode;
-    private DOMElement $functionsNode;
-    private DOMElement $classesNode;
-    private DOMElement $traitsNode;
+    private XMLWriter $xmlWriter;
 
-    public function __construct(DOMElement $container)
+    public function __construct(XMLWriter $xmlWriter)
     {
-        $dom = $container->ownerDocument;
-
-        $this->linesNode = $dom->createElementNS(
-            Facade::XML_NAMESPACE,
-            'lines',
-        );
-
-        $this->methodsNode = $dom->createElementNS(
-            Facade::XML_NAMESPACE,
-            'methods',
-        );
-
-        $this->functionsNode = $dom->createElementNS(
-            Facade::XML_NAMESPACE,
-            'functions',
-        );
-
-        $this->classesNode = $dom->createElementNS(
-            Facade::XML_NAMESPACE,
-            'classes',
-        );
-
-        $this->traitsNode = $dom->createElementNS(
-            Facade::XML_NAMESPACE,
-            'traits',
-        );
-
-        $container->appendChild($this->linesNode);
-        $container->appendChild($this->methodsNode);
-        $container->appendChild($this->functionsNode);
-        $container->appendChild($this->classesNode);
-        $container->appendChild($this->traitsNode);
+        $this->xmlWriter = $xmlWriter;
     }
 
     public function setNumLines(int $loc, int $cloc, int $ncloc, int $executable, int $executed): void
     {
-        $this->linesNode->setAttribute('total', (string) $loc);
-        $this->linesNode->setAttribute('comments', (string) $cloc);
-        $this->linesNode->setAttribute('code', (string) $ncloc);
-        $this->linesNode->setAttribute('executable', (string) $executable);
-        $this->linesNode->setAttribute('executed', (string) $executed);
-        $this->linesNode->setAttribute(
+        $this->xmlWriter->startElement('lines');
+        $this->xmlWriter->writeAttribute('total', (string) $loc);
+        $this->xmlWriter->writeAttribute('comments', (string) $cloc);
+        $this->xmlWriter->writeAttribute('code', (string) $ncloc);
+        $this->xmlWriter->writeAttribute('executable', (string) $executable);
+        $this->xmlWriter->writeAttribute('executed', (string) $executed);
+        $this->xmlWriter->writeAttribute(
             'percent',
             $executable === 0 ? '0' : sprintf('%01.2F', Percentage::fromFractionAndTotal($executed, $executable)->asFloat()),
         );
+        $this->xmlWriter->endElement();
     }
 
     public function setNumClasses(int $count, int $tested): void
     {
-        $this->classesNode->setAttribute('count', (string) $count);
-        $this->classesNode->setAttribute('tested', (string) $tested);
-        $this->classesNode->setAttribute(
+        $this->xmlWriter->startElement('classes');
+        $this->xmlWriter->writeAttribute('count', (string) $count);
+        $this->xmlWriter->writeAttribute('tested', (string) $tested);
+        $this->xmlWriter->writeAttribute(
             'percent',
             $count === 0 ? '0' : sprintf('%01.2F', Percentage::fromFractionAndTotal($tested, $count)->asFloat()),
         );
+        $this->xmlWriter->endElement();
     }
 
     public function setNumTraits(int $count, int $tested): void
     {
-        $this->traitsNode->setAttribute('count', (string) $count);
-        $this->traitsNode->setAttribute('tested', (string) $tested);
-        $this->traitsNode->setAttribute(
+        $this->xmlWriter->startElement('traits');
+        $this->xmlWriter->writeAttribute('count', (string) $count);
+        $this->xmlWriter->writeAttribute('tested', (string) $tested);
+        $this->xmlWriter->writeAttribute(
             'percent',
             $count === 0 ? '0' : sprintf('%01.2F', Percentage::fromFractionAndTotal($tested, $count)->asFloat()),
         );
+        $this->xmlWriter->endElement();
     }
 
     public function setNumMethods(int $count, int $tested): void
     {
-        $this->methodsNode->setAttribute('count', (string) $count);
-        $this->methodsNode->setAttribute('tested', (string) $tested);
-        $this->methodsNode->setAttribute(
+        $this->xmlWriter->startElement('methods');
+        $this->xmlWriter->writeAttribute('count', (string) $count);
+        $this->xmlWriter->writeAttribute('tested', (string) $tested);
+        $this->xmlWriter->writeAttribute(
             'percent',
             $count === 0 ? '0' : sprintf('%01.2F', Percentage::fromFractionAndTotal($tested, $count)->asFloat()),
         );
+        $this->xmlWriter->endElement();
     }
 
     public function setNumFunctions(int $count, int $tested): void
     {
-        $this->functionsNode->setAttribute('count', (string) $count);
-        $this->functionsNode->setAttribute('tested', (string) $tested);
-        $this->functionsNode->setAttribute(
+        $this->xmlWriter->startElement('functions');
+        $this->xmlWriter->writeAttribute('count', (string) $count);
+        $this->xmlWriter->writeAttribute('tested', (string) $tested);
+        $this->xmlWriter->writeAttribute(
             'percent',
             $count === 0 ? '0' : sprintf('%01.2F', Percentage::fromFractionAndTotal($tested, $count)->asFloat()),
         );
+        $this->xmlWriter->endElement();
+    }
+
+    public function getWriter(): XMLWriter
+    {
+        return $this->xmlWriter;
     }
 }
diff --git a/src/Report/Xml/Unit.php b/src/Report/Xml/Unit.php
index fa97909c2..bfc5029c4 100644
--- a/src/Report/Xml/Unit.php
+++ b/src/Report/Xml/Unit.php
@@ -9,18 +9,17 @@
  */
 namespace SebastianBergmann\CodeCoverage\Report\Xml;
 
-use function assert;
-use DOMElement;
+use XMLWriter;
 
 /**
  * @internal This class is not covered by the backward compatibility promise for phpunit/php-code-coverage
  */
 final readonly class Unit
 {
-    private DOMElement $contextNode;
+    private XMLWriter $xmlWriter;
 
     public function __construct(
-        DOMElement $context,
+        XMLWriter $xmlWriter,
         string $name,
         string $namespace,
         int $start,
@@ -28,23 +27,17 @@ public function __construct(
         int $executed,
         float $crap
     ) {
-        $this->contextNode = $context;
+        $this->xmlWriter = $xmlWriter;
 
-        $this->contextNode->setAttribute('name', $name);
-        $this->contextNode->setAttribute('start', (string) $start);
-        $this->contextNode->setAttribute('executable', (string) $executable);
-        $this->contextNode->setAttribute('executed', (string) $executed);
-        $this->contextNode->setAttribute('crap', (string) $crap);
+        $this->xmlWriter->writeAttribute('name', $name);
+        $this->xmlWriter->writeAttribute('start', (string) $start);
+        $this->xmlWriter->writeAttribute('executable', (string) $executable);
+        $this->xmlWriter->writeAttribute('executed', (string) $executed);
+        $this->xmlWriter->writeAttribute('crap', (string) $crap);
 
-        $node = $this->contextNode->appendChild(
-            $this->contextNode->ownerDocument->createElementNS(
-                Facade::XML_NAMESPACE,
-                'namespace',
-            ),
-        );
-        assert($node instanceof DOMElement);
-
-        $node->setAttribute('name', $namespace);
+        $this->xmlWriter->startElement('namespace');
+        $this->xmlWriter->writeAttribute('name', $namespace);
+        $this->xmlWriter->endElement();
     }
 
     public function addMethod(
@@ -57,17 +50,8 @@ public function addMethod(
         string $coverage,
         string $crap
     ): void {
-        $node = $this->contextNode->appendChild(
-            $this->contextNode->ownerDocument->createElementNS(
-                Facade::XML_NAMESPACE,
-                'method',
-            ),
-        );
-
-        assert($node instanceof DOMElement);
-
         new Method(
-            $node,
+            $this->xmlWriter,
             $name,
             $signature,
             $start,
diff --git a/tests/_files/Report/XML/CoverageForBankAccount/BankAccount.php.xml b/tests/_files/Report/XML/CoverageForBankAccount/BankAccount.php.xml
index b49cdf8ed..fa5cab570 100644
--- a/tests/_files/Report/XML/CoverageForBankAccount/BankAccount.php.xml
+++ b/tests/_files/Report/XML/CoverageForBankAccount/BankAccount.php.xml
@@ -35,7 +35,7 @@
         <covered by="BankAccountTest::testDepositWithdrawMoney"/>
       </line>
     </coverage>
-    <source>
+    <source xmlns="https://schema.phpunit.de/coverage/1.0">
       <line no="1">
         <token name="T_OPEN_TAG">&lt;?php</token>
       </line>
diff --git a/tests/_files/Report/XML/CoverageForClassWithAnonymousFunction/source_with_class_and_anonymous_function.php.xml b/tests/_files/Report/XML/CoverageForClassWithAnonymousFunction/source_with_class_and_anonymous_function.php.xml
index 95d121dc8..5f488ee82 100644
--- a/tests/_files/Report/XML/CoverageForClassWithAnonymousFunction/source_with_class_and_anonymous_function.php.xml
+++ b/tests/_files/Report/XML/CoverageForClassWithAnonymousFunction/source_with_class_and_anonymous_function.php.xml
@@ -38,7 +38,7 @@
         <covered by="ClassWithAnonymousFunction"/>
       </line>
     </coverage>
-    <source>
+    <source xmlns="https://schema.phpunit.de/coverage/1.0">
       <line no="1">
         <token name="T_OPEN_TAG">&lt;?php</token>
       </line>
diff --git a/tests/_files/Report/XML/CoverageForFileWithIgnoredLines/source_with_ignore.php.xml b/tests/_files/Report/XML/CoverageForFileWithIgnoredLines/source_with_ignore.php.xml
index b862f3d1e..89c105012 100644
--- a/tests/_files/Report/XML/CoverageForFileWithIgnoredLines/source_with_ignore.php.xml
+++ b/tests/_files/Report/XML/CoverageForFileWithIgnoredLines/source_with_ignore.php.xml
@@ -22,7 +22,7 @@
         <covered by="FileWithIgnoredLines"/>
       </line>
     </coverage>
-    <source>
+    <source xmlns="https://schema.phpunit.de/coverage/1.0">
       <line no="1">
         <token name="T_OPEN_TAG">&lt;?php</token>
       </line>